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  1. 4 points
    geemap is a Python package for interactive mapping with Google Earth Engine (GEE), which is a cloud computing platform with a multi-petabyte catalog of satellite imagery and geospatial datasets. During the past few years, GEE has become very popular in the geospatial community and it has empowered numerous environmental applications at local, regional, and global scales. GEE provides both JavaScript and Python APIs for making computational requests to the Earth Engine servers. Compared with the comprehensive documentation and interactive IDE (i.e., GEE JavaScript Code Editor) of the GEE JavaScript API, the GEE Python API lacks good documentation and functionality for visualizing results interactively. The geemap Python package is created to fill this gap. It is built upon ipyleaflet and ipywidgets, enabling GEE users to analyze and visualize Earth Engine datasets interactively with Jupyter notebooks. geemap is intended for students and researchers, who would like to utilize the Python ecosystem of diverse libraries and tools to explore Google Earth Engine. It is also designed for existing GEE users who would like to transition from the GEE JavaScript API to Python API. The automated JavaScript-to-Python conversion module of the geemap package can greatly reduce the time needed to convert existing GEE JavaScripts to Python scripts and Jupyter notebooks. For video tutorials and notebook examples, please visit https://github.com/giswqs/geemap/tree/master/examples. For complete documentation on geemap modules and methods, please visit https://geemap.readthedocs.io/en/latest/source/geemap.html. Features Below is a partial list of features available for the geemap package. Please check the examples page for notebook examples, GIF animations, and video tutorials. Automated conversion from Earth Engine JavaScripts to Python scripts and Jupyter notebooks. Displaying Earth Engine data layers for interactive mapping. Supporting Earth Engine JavaScript API-styled functions in Python, such as Map.addLayer(), Map.setCenter(), Map.centerObject(), Map.setOptions(). Creating split-panel maps with Earth Engine data. Retrieving Earth Engine data interactively using the Inspector Tool. Interactive plotting of Earth Engine data by simply clicking on the map. Converting data format between GeoJSON and Earth Engine. Using drawing tools to interact with Earth Engine data. Using shapefiles with Earth Engine without having to upload data to one's GEE account. Exporting Earth Engine FeatureCollection to other formats (i.e., shp, csv, json, kml, kmz) using only one line of code. Exporting Earth Engine Image and ImageCollection as GeoTIFF. Extracting pixels from an Earth Engine Image into a 3D numpy array. Calculating zonal statistics by group (e.g., calculating land over composition of each state/country). Adding a customized legend for Earth Engine data. Converting Earth Engine JavaScripts to Python code directly within Jupyter notebook. Adding animated text to GIF images generated from Earth Engine data. Adding colorbar and images to GIF animations generated from Earth Engine data. Creating Landsat timelapse animations with animated text using Earth Engine. Searching places and datasets from Earth Engine Data Catalog. Using timeseries inspector to visualize landscape changes over time. Exporting Earth Engine maps as HTML files and PNG images. Searching Earth Engine API documentation within Jupyter notebooks. Installation To use geemap, you must first sign up for a Google Earth Engine account. geemap is available on PyPI. To install geemap, run this command in your terminal: pip install geemap geemap is also available on conda-forge. If you have Anaconda or Miniconda installed on your computer, you can create a conda Python environment to install geemap: conda create -n gee python conda activate gee conda install -c conda-forge geemap If you have installed geemap before and want to upgrade to the latest version, you can run the following command in your terminal: pip install -U geemap If you use conda, you can update geemap to the latest version by running the following command in your terminal: conda update -c conda-forge geemap Usage Important note: A key difference between ipyleaflet and folium is that ipyleaflet is built upon ipywidgets and allows bidirectional communication between the front-end and the backend enabling the use of the map to capture user input, while folium is meant for displaying static data only (source). Note that Google Colab currently does not support ipyleaflet (source). Therefore, if you are using geemap with Google Colab, you should use import geemap.eefolium. If you are using geemap with binder or a local Jupyter notebook server, you can use import geemap, which provides more functionalities for capturing user input (e.g., mouse-clicking and moving). Youtube tutorial videos GitHub page of geemap Documentation While working on a small project I found this. This is a quite new library, some features shown in the tutorial may not work as intended but overall a very good package. The tools make the code much cleaner and readable. Searching EE docs from notebook is not yet implemented. Check out the youtube channel, it's great.
  2. 3 points
    Our objective is to provide the scientific and civil communities with a state-of-the-art global digital elevation model (DEM) derived from a combination of Shuttle Radar Topography Mission (SRTM) processing improvements, elevation control, void-filling and merging with data unavailable at the time of the original SRTM production: NASA SRTM DEMs created with processing improvements at full resolution NASA's Ice, Cloud,and land Elevation Satellite (ICESat)/Geoscience Laser Altimeter (GLAS) surface elevation measurements DEM cells derived from stereo optical methods using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data from the Terra satellite Global DEM (GDEM) ASTER products developed for NASA and the Ministry of Economy, Trade and Industry of Japan by Sensor Information Laboratory Corp National Elevation Data for US and Mexico produced by the USGS Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) developed by the USGS and the National Geospatial-Intelligence Agency (NGA) Canadian Digital Elevation Data produced by Natural Resources Canada We propose a significant modernization of the publicly- and freely-available DEM data. Accurate surface elevation information is a critical component in scientific research and commercial and military applications. The current SRTM DEM product is the most intensely downloaded dataset in NASA history. However, the original Memorandum of Understanding (MOU) between NASA and NGA has a number of restrictions and limitations; the original full resolution, one-arcsecond data are currently only available over the US and the error, backscatter and coherence layers were not released to the public. With the recent expiration of the MOU, we propose to reprocess the original SRTM raw radar data using improved algorithms and incorporating ancillary data that were unavailable during the original SRTM processing, and to produce and publicly release a void-free global one-arcsecond (~30m) DEM and error map, with the spacing supported by the full-resolution SRTM data. We will reprocess the entire SRTM dataset from raw sensor measurements with validated improvements to the original processing algorithms. We will incorporate GLAS data to remove artifacts at the optimal step in the SRTM processing chain. We will merge the improved SRTM strip DEMs, refined ASTER and GDEM V2 DEMs, and GLAS data using the SRTM mosaic software to create a seamless, void-filled NASADEM. In addition, we will provide several new data layers not publicly available from the original SRTM processing: interferometric coherence, radar backscatter, radar incidence angle to enable radiometric correction, and a radar backscatter image mosaic to be used as a layer for global classification of land cover and land use. This work leverages an FY12 $1M investment from NASA to make several improvements to the original algorithms. We validated our results with the original SRTM products and ancillary elevation information at a few study sites. Our approach will merge the reprocessed SRTM data with the DEM void-filling strategy developed during NASA's Making Earth System Data Records for Use in Research Environments (MEaSUREs) 2006 project, "The Definitive Merged Global Digital Topographic Data Set" of Co-Investigator Kobrick. NASADEM is a significant improvement over the available three-arcsecond SRTM DEM primarily because it will provide a global DEM and associated products at one-arcsecond spacing. ASTER GDEM is available at one-arcsecond spacing but has true spatial resolution generally inferior to SRTM one-arcsecond data and has much greater noise problems that are particularly severe in tropical (cloudy) areas. At one-arcsecond, NASADEM will be superior to GDEM across almost all SRTM coverage areas, but will integrate GDEM and other data to extend the coverage. Meanwhile, DEMs from the Deutsches Zentrum für Luft- und Raumfahrt Tandem-X mission are being developed as part of a public-private partnership. However, these data must be purchased and are not redistributable. NASADEM will be the finest resolution, global, freely-available DEM products for the foreseeable future. data page: https://lpdaac.usgs.gov/products/nasadem_hgtv001/ news links: https://earthdata.nasa.gov/esds/competitive-programs/measures/nasadem
  3. 3 points
    Interesting application of WebGIS to plot Dinosaur database, and you can search how is your place in the past on the interactive globe Map. Welcome to the internet's largest dinosaur database. Check out a random dinosaur, search for one below, or look at our interactive globe of ancient Earth! Whether you are a kid, student, or teacher, you'll find a rich set of dinosaur names, pictures, and facts here. This site is built with PaleoDB, a scientific database assembled by hundreds of paleontologists over the past two decades. check this interactive webgis apps: https://dinosaurpictures.org/ancient-earth#170 official link: https://dinosaurpictures.org/
  4. 3 points
    link: https://press.anu.edu.au/publications/new-releases
  5. 3 points
    Interesting video on How Tos: WebOpenDroneMap is a friendly Graphical User Interfase (GUI) of OpenDroneMap. It enhances the capabilities of OpenDroneMap by providing a easy tool for processing drone imagery with bottoms, process status bars, and a new way to store images. WebODM allows to work by projects, so the user can create different projects and process the related images. As a whole, WebODM in Windows is a implementation of PostgresSQL, Node, Django and OpenDroneMap and Docker. The software instalation requires 6gb of disk space plus Docker. It seem huge but it is the only way to process drone imagery in Windows using just open source software. We definitely see a huge potential of WebODM for the image processing, therefore we have done this tutorial for the installation and we will post more tutorial for the application of WebODM with drone images. For this tutorial you need Docker Toolbox installed on your computer. You can follow this tutorial to get Docker on your pc: https://www.hatarilabs.com/ih-en/tutorial-installing-docker You can visit the WebODM site on GitHub: https://github.com/OpenDroneMap/WebODM Videos The tutorial was split in three short videos. Part 1 https://www.youtube.com/watch?v=AsMSoWAToxE Part 2 https://www.youtube.com/watch?v=8GKx3fz0qgE Part 3 https://www.youtube.com/watch?v=eCZFzaXyMmA
  6. 3 points
    7th International Conference on Computer Science and Information Technology (CoSIT 2020) January 25 ~ 26, 2020, Zurich, Switzerland https://cosit2020.org/ Scope & Topics 7th International Conference on Computer Science and Information Technology (CoSIT 2020) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of Computer Science, Engineering and Information Technology. The Conference looks for significant contributions to all major fields of the Computer Science and Information Technology in theoretical and practical aspects. The aim of the conference is to provide a platform to the researchers and practitioners from both academia as well as industry to meet and share cutting-edge development in the field. Authors are solicited to contribute to the conference by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe · Geographical Information Systems/ Global Navigation Satellite Systems (GIS/GNSS) Paper Submission Authors are invited to submit papers through the conference Submission system. Here’s where you can reach us : [email protected] or [email protected]
  7. 3 points
    The first thing to do before mapping is to set up the camera parameters. Before to set up camera parameters, recommended resetting the all parameters on camera first. To set camera parameters manually need to set to manual mode. Image quality: Extra fine Shutter speed: to remove blur from photo shutter speed should be set for higher value. 1200–1600 is recommended. Higher the shutter speed reduce image quality . if there is blur in the image increase shutter speed ISO: lower the ISO higher image quality. ISO between 160–300 is recommended. if there is no blur but image quality is low, reduce ISO. Focus: Recommended to set the focus manually on the ground before a flight. Direct camera to an object which is far, and slightly increase the focus, you will see on camera screen that image sharpness changes by changing the value. Set the image sharpness at highest. (slide the slider close to infinity point on the screen you will see the how image sharpness changes by sliding) White balance: recommended to set to auto. On surveying mission Sidelap, Overlap, Buffer have to be set higher to get better quality surveying result. First set the RESOLUTION which you would like to get for your surveying project. When you change resolution it changes flight altitude and also effects the coverage in a single flight. Overlap: 70% This will increase the number of photos taken during each flight line. The camera should be capable to capture faster. Sidelap: recommended 70% Flying with higher side-lap between each line of the flight is a way to get more matches in the imagery, but it also reduces the coverage in a single flight Buffer: 12% Buffer increases the flight plane to get more images from borders. It will improve the quality of the map source: https://dronee.aero/blogs/dronee-pilot-blog/few-things-to-set-correctly-to-get-high-quality-surveying-results
  8. 3 points
    The GeoforGood Summit 2019 drew its curtains close on 19 Sep 2019 and as a first time attendee, I was amazed to see the number of new developments announced at the summit. The summit — being a first of its kind — combined the user summit and the developers summit into one to let users benefit from the knowledge of new tools and developers understand the needs of the user. Since my primary focus was on large scale geospatial modeling, I attended the workshops and breakout sessions related to Google Earth Engine only. With that, let’s look at 3 new exciting developments to hit Earth Engine Updated documentation on machine learning Documentation really? Yes! As an amateur Earth Engine user myself, my number one complaint of the tool has been its abysmal quality of documentation spread between its app developers site, Google Earth’s blog, and their stack exchange answers. So any updates to the documentation is welcome. I am glad that the documentation has been updated to help the ever-exploding user base of geospatial data scientists interested in implementing machine learning and deep learning models. The documentation comes with its own example Colab notebooks. The Example notebooks include supervised classification, unsupervised classification, dense neural network, convolutional neural network, and deeplearning on Google Cloud. I found that these notebooks were incredibly useful to me to get started as there are quite a few non-trivial data type conversions ( int to float32 and so on) in the process flow. Earth Engine and AI Platform Integration Nick Clinton and Chris Brown jointly announced the much overdue Earth Engine + Google AI Platform integration. Until now, users were essentially limited to running small jobs on Google Colab’s virtual machine (VM) and hoping that the connection with the VM doesn’t time out (which usually lasts for about 4 hours). Other limitations include lack of any task monitoring or queuing capabilities. Not anymore! The new ee.Model() package let’s users communicate with a Google Cloud server that they can spin up based on their own needs. Needless to say, this is a HUGE improvement over the previous primitive deep learning support provided on the VM. Although it was free, one could simply not train, validate, predict, and deploy any model larger than a few layers. It had to be done separately on the Google AI Platform once the .TFRecord objects were created in their Google bucket. With this cloud integration, that task has been simplified tremendously by letting users run and test their models right from the Colab environment. The ee.Model() class comes with some useful functions such as ee.Model.fromAIPlatformPredictor() to make predictions on Earth Engine data directly from your model sitting on Google Cloud. Lastly, since your model now sits in the AI Platform, you can cheat and use your own models trained offline to predict on Earth Engine data and make maps of its output. Note that your model must be saved using tf.contrib.saved_model format if you wish to do so. The popular Keras function model.save_model('model.h5') is not compatible with ee.Model(). Moving forward, it seems like the team plans to stick to the Colab Python IDE for all deep learning applications. However, it’s not a death blow for the loved javascript code editor. At the summit, I saw that participants still preferred the javascript code editor for their non-neural based machine learning work (like support vector machines, random forests etc.). Being a python lover myself, I too go to the code editor for quick visualizations and for Earth Engine Apps! I did not get to try out the new ee.Model() package at the summit but Nick Clinton demonstrated a notebook where a simple working example has been hosted to help us learn the function calls. Some kinks still remain in the development— like limiting a convolution kernel to only 144 pixels wide during prediction because of “the way earth engine communicates with cloud platform” — but he assured us that it will be fixed soon. Overall, I am excited about the integration because Earth Engine is now a real alternative for my geospatial computing work. And with the Earth Engine team promising more new functions in the ee.Model() class, I wonder if companies and labs around the world will start migrating their modeling work to Earth Engine. Cooler Visualizations! Matt Hancher and Tyler Erickson displayed some new functionality related to visualizations and I found that it made it vastly simpler to make animated visuals. With ee.ImageCollection.getVideoThumbURL() function, you can create your own animated gifs within a few seconds! I tried it on a bunch of datasets and the speed of creating the gifs was truly impressive. Say bye to exporting each iteration of a video to your drive because these gifs appear right at the console using the print() command! Shown above is an example of global temperature forecast by time from the ‘NOAA/GFS0P25’ dataset. The code for making the gif can be found here. The animation is based on the example shown in the original blog post by Michael DeWitt and I referred to this gif-making tutorial on the developers page to make it. I did not get to cover all the new features and functionality introduced at the summit. For that, be on the lookout for event highlights on Google Earth’s blog. Meanwhile, you can check out the session resources from the summit for presentations and notebooks on topics that you are interested in. Presentation and resources Published in Medium
  9. 3 points
    Details geological-geophysical aspects of groundwater treatment Discusses regulatory legislations regarding groundwater utilization Serves as a reference material for scientists in geology, geophysics and environmental studies
  10. 2 points
    Hi Everyone, July 13–16, 2020 | The world’s largest, virtual GIS event (FREE this year) The 2020 Esri User Conference (Esri UC) is a completely virtual event designed to give users and students an interactive, online experience with Esri and the GIS community. Participate in sessions and view presentations that offer geospatial solutions, browse the online Map Gallery, watch the Plenary Session, and much more. Registration here : https://www.esri.com/en-us/about/events/uc/overview Enjoy
  11. 2 points
    the satellites from planet can now take imagery at 50cm, they changed their orbit in order to achieve better GSD SKYSAT IMAGERY NOW AVAILABLE Bring agility to your organization with the latest advancements in high-resolution SkySat imagery, available today. Make targeted decisions in ever-changing operational contexts with improved 50 cm spatial resolution and more transparency in the ordering process with the new Tasking Dashboard.
  12. 2 points
    for those like me who are not English mother tongue I recommend this site for translations (English - French - German - Italian - Spanish - Portuguese - Russian - Chinese - Japanese etc.)... fantastic and intuitive that is based on artificial intelligence https://www.deepl.com/ another interesting website https://www.linguee.com/
  13. 2 points
    A new set of 10 ArcGIS Pro lessons empowers GIS practitioners, instructors, and students with essential skills to find, acquire, format, and analyze public domain spatial data to make decisions. Described in this video, this set was created for 3 reasons: (1) to provide a set of analytical lessons that can be immediately used, (2) to update the original 10 lessons created by my colleague Jill Clark and I to provide a practical component to our Esri Press book The GIS Guide to Public Domain Data, and (3) to demonstrate how ArcGIS Desktop (ArcMap) lessons can be converted to Pro and to reflect upon that process. The activities can be found here. This essay is mirrored on the Esri GeoNet education blog and the reflections are below and in this video. Summary of Lessons: Can be used in full, in part, or modified to suit your own needs. 10 lessons. 64 work packages. A “work package” is a set of tasks focused on solving a specific problem. 370 guided steps. 29 to 42 hours of hands-on immersion. Over 600 pages of content. 100 skills are fostered, covering GIS tools and methods, working with data, and communication. 40 data sources are used, covering 85 different data layers. Themes covered: climate, business, population, fire, floods, hurricanes, land use, sustainability, ecotourism, invasive species, oil spills, volcanoes, earthquakes, agriculture. Areas covered: The Globe, and also: Brazil, New Zealand, the Great Lakes of the USA, Canada, the Gulf of Mexico, Iceland, the Caribbean Sea, Kenya, Orange County California, Nebraska, Colorado, and Texas USA. Aimed at university-level graduate and university or community college undergraduate student. Some GIS experience is very helpful, though not absolutely required. Still, my advice is not to use these lessons for students’ first exposure to GIS, but rather, in an intermediate or advanced setting. How to access the lessons: The ideal way to work through the lessons is in a Learn Path which bundle the readings of the book’s chapters, selected blog essays, and the hands-on activities.. The Learn Path is split into 3 parts, as follows: Solving Problems with GIS and public domain geospatial data 1 of 3: Learn how to find, evaluate, and analyze data to solve location-based problems through this set of 10 chapters and short essay readings, and 10 hands-on lessons: https://learn.arcgis.com/en/paths/the-gis-guide-to-public-domain-data-learn-path/ Solving Problems with GIS and public domain geospatial data 2 of 3: https://learn.arcgis.com/en/paths/the-gis-guide-to-public-domain-data-learn-path-2/ Solving Problems with GIS and public domain geospatial data 3 of 3: https://learn.arcgis.com/en/paths/the-gis-guide-to-public-domain-data-learn-path-3/ The Learn Paths allow for content to be worked through in sequence, as shown below: You can also access the lessons by accessing this gallery in ArcGIS Online, shown below. If you would like to modify the lessons for your own use, feel free! This is why the lessons have been provided in a zipped bundle as PDF files here and as MS Word DOCX files here. This video provides an overview. source: https://spatialreserves.wordpress.com/2020/05/14/10-new-arcgis-pro-lesson-activities-learn-paths-and-migration-reflections/
  14. 2 points
    Stop me if you’ve heard this before. DJI has introduced its latest enterprise powerhouse drone, the DJI Matrice 300 RTK. We learned a lot about the drone earlier this week due to a few huge leaks of specs, features, photos, and videos. But it’s worth looking at the drone again now that it’s official – and an incredible intro video. Also called the M300 RTK, this drone is an upgrade in every way over its predecessor, the M200 V2. That includes a very long flight time of 55 minutes, six-direction obstacle avoidance, and a doubled (6 pound) payload capability. That allows it to carry a range of powerful cameras, which we’ll get to in a bit. The drone is also built for weather extremes. IP45 weather sealing keeps out rain and dust. And a self-heating battery helps the drone to run in a broad range of temperatures, from -4 to 122 Fahrenheit. The DJI Matrice 300 RTK can fly up to 15 kilometers (9.3 miles) from its controller and still stream 1080p video back home. That video and other data can be protected using AES-256 encryption. The drone can also be flown by two co-pilots, with one able to take over for the other if any problem arises or a handoff scenario. A workhorse inspection drone All these capabilities are targeted to the DJI Matrice 300 RTK’s purpose as a drone for heavy-duty visual inspection and data collection work, such as surveys of power lines or railways. In fact, it incorporates many advanced camera features for the purpose. Smart inspection is a new set of features to optimize data collection. It includes live mission recording, which allows the drone to record every aspect of a flight, even camera settings. This allows workers to train a drone on an inspection mission that it will repeat again and again. With AI spot check, operators can mark the specific part of the photo, such as a transformer, that is the subject of inspection. AI algorithms compare that to what the camera sees on a future flight, so that it can frame the subject identically on every flight. An inspection drone is only as good as its cameras, and the M300 RTK offers some powerful options from DJI’s Zenmuse H20 series. The first option is a triple-camera setup. It includes a 20-megapixel, 23x zoom camera; a 12MP wide-angle camera; and a laser rangefinder that measures out to 1,200 meters (3,937 feet). The second option adds a radiometric thermal camera. TO make things simpler for operators, the drone provides a one-click capture feature that grabs videos or photos from three cameras at once, without requiring the operator to switch back and forth. Eyes and ears ready for danger With its flight time and range, the DJI Matrice 300 RTK could be flying some long, complex missions, easily beyond visual line of site (if its owner gets an FAA Part 107 waiver for that). This requires some solid safety measures. While the M200 V2 has front-mounted sensors, the M300 RTK has sensors in six directions for full view of the surroundings. The sensors can register obstacles up to 40 meters (98 feet) away. Like all new DJI drones, the M300 RTK also features the company’s AirSense technology. An ADS-B receiver picks up signals from manned aircraft that are nearby and alerts the drone pilot of their location. It’s been quite a few weeks for DJI. On April 27, it debuted its most compelling consumer drone yet, the Mavic Air 2. Now it’s showing off its latest achievement at the other end of the drone spectrum with the industrial grade Matrice 300 RTK. These two, very different drones help illustrate the depth of product that comes from the world’s biggest drone maker. And the company doesn’t show signs of slowing down, despite the COVID-19 economic crisis. Next up, we suspect, will be a revision to its semi-pro quadcopter line in the firm of a Mavic 3. It is available at DJI.It’s been quite a few weeks for DJI. On April 27, it debuted its most compelling consumer drone yet, the Mavic Air 2. Now it’s showing off its latest achievement at the other end of the drone spectrum with the industrial grade Matrice 300 RTK. These two, very different drones help illustrate the depth of product that comes from the world’s biggest drone maker. And the company doesn’t show signs of slowing down, despite the COVID-19 economic crisis. Next up, we suspect, will be a revision to its semi-pro quadcopter line in the firm of a Mavic 3. It is available at DJI. source: https://dronedj.com/2020/05/07/dji-matrice-300-rtk-drone-official/
  15. 2 points
    @intertronic, thanks for your input. I found a solution that suite my case better due to the fact that we are using both version of QGIS and also because I was looking for interoperability. Therefore I have decided to use QSphere. Most probably not well known around the globe. https://qgis.projets.developpement-durable.gouv.fr/projects/qsphere GUI quiete ugly but at least is doing the job. 😉 darksabersan
  16. 2 points
    DRONE MAKER DJI announced an update to its popular Mavic Air quadcopter today. The Mavic Air 2 will cost $799 when it ships to US buyers in late May. That's the same price as the previous Mavic Air model, so the drone stays as DJI's mid-range option between its more capable Mavic 2 and its smaller, cheaper Mavic Mini. The Mavic Air 2 is still plenty small, but the new version has put on some weight. DJI says that testing and consumer surveys suggested that most people don't mind lugging a few extra grams in exchange for a considerable upgrade in flight time and, presumably, better handling in windy conditions. Even better, thanks to a new rotor design and other aerodynamic improvements, DJI is claiming the Mavic Air 2 can remain aloft for 34 minutes—a big jump from the 21 minutes of flight time on the original Mavic Air. The Camera Eye he big news in this update is the new larger imaging sensor on the drone's camera. The Mavic Air 2's camera ships with a half-inch sensor, up from the 1 2/3-inch sensor found in the previous model. That should mean better resolution and sharper images, especially because the output specs haven't changed much. The new camera is still outputting 12-megapixel stills, but now has a bigger sensor to fill that frame with more detail. There's also a new composite image option that joins together multiple single shots into a large, 48-megapixel image. On the video side, there's some exciting news. The Mavic Air 2 is DJI's first drone to offer 4K video at 60 frames per second and 120 Mbps—previous DJI drones topped out at 30 fps when shooting in full 4K resolution. There are also slow-motion modes that slow down footage to four times slower than real life (1080p at 120 fps), or eight-times slower (1080 at 240 fps). Combine those modes with the more realistic contrast you get with the HDR video standard, and you have considerably improved video capabilities in a sub-$1,000 drone. More interesting in some ways is DJI's increasing forays into computational photography, which the company calls Smart Photo mode. Flip on Smart Photo and the Mavic Air 2 will do scene analysis, tap its machine intelligence algorithm and automatically choose between a variety of photo modes. There's a scene recognition mode where the Mavic Air 2 sets the camera up to best capture one of a variety of scenarios you're likely to encounter with drone photography, including blue skies, sunsets, snow, grass, and trees. In each case, exposure is adjusted to optimize tone and detail. The second Smart Photo mode is dubbed Hyperlight, which handles low-light situations. To judge by DJI's promo materials, this is essentially an HDR photography mode specifically optimized for low-light scenes. It purportedly cuts noise and produces more detailed images. The final smart mode is HDR, which takes seven images in rapid succession, the combines elements of each to make a final image with a higher dynamic range. One last note about the camera: The shape of the camera has changed, so if you have any lenses or other accessories for previous DJI drones, they won't attach to the Air 2. Automatic Flight for the People If you dig through older YouTube videos there's a ton of movies that play out like this: unbox new drone, head outside, take off, tree gets closer, closer, closer, black screen. Most of us just aren't that good at flying, and the learning curve can be expensive and steep. Thankfully drone companies began automating away most of what's difficult about piloting a quadcopter, and DJI is no exception. The company has added some new automated flight tricks to the Air's arsenal. DJI's Active Track has been updated to version 3.0, which brings better subject recognition algorithms and some new 3D mapping tricks to make it easier to automatically track people through a scene, keeping the camera on the subject as the drone navigates overhead to stay with them. DJI claims the Point of Interest mode—which allows you to select an object and fly around it in a big circle while the camera stays pointed at the subject—is better at tracking some of the objects that previous versions struggled with, like vehicles or even people. The most exciting new flight mode is Spotlight, which comes from DJI's high-end Inspire drone used by professional photographers and videographers to carry their DSLR cameras into the sky. Similar to the Active Track mode, Spotlight keeps the camera pointed a moving subject. But while Active Track automates the drone's flight, the new Spotlight mode allows the human pilot to retain control of the flight path for more complex shots. Finally, the range of the new Mavic Air 2 has been improved, and it can now wander an impressive six miles away from the pilot in ideal conditions. The caveat here is that you should always maintain visual contact with your drone for safety reasons. However, you aren't going to be able to see the Mavic Air 2 when it's two miles away, let alone six. Despite a dearth of competitors, DJI continues to put out new drones and improve its lineup as it progresses. The Mavic Air 2 looks like an impressive update to what was already one of our favorite drones, especially considering several features—the 60 fps 4K video and 34 minute flight time—even best those found on the more expensive Mavic 2 Pro. links: https://www.dji.com/id/mavic-air-2
  17. 2 points
    I like drones but just got more interested in this,
  18. 2 points
    Harvard Online Courses Advance your career. Pursue your passion. Keep learning. links: https://online-learning.harvard.edu/CATALOG/FREE
  19. 2 points
  20. 2 points
    Saw a similar news last month - Using Machine Learning to “Nowcast” Precipitation in High Resolution by Google. The result seemed pretty good. Here, A visualization of predictions made over the course of roughly one day. Left: The 1-hour HRRR prediction made at the top of each hour, the limit to how often HRRR provides predictions. Center: The ground truth, i.e., what we are trying to predict. Right: The predictions made by our model. Our predictions are every 2 minutes (displayed here every 15 minutes) at roughly 10 times the spatial resolution made by HRRR. Notice that we capture the general motion and general shape of the storm. The two method seem similar.
  21. 2 points
    With Huawei basically blocked from using Google services and infrastructure, the firm has taken steps to replace Google Maps on its hardware by signing a partnership with TomTom to provide maps, navigation, and traffic data to Huawei apps. Reuters reports that Huawei is entering this partnership with TomTom as the mapping tech company is based in the Netherlands — therefore side-stepping the bans on working with US firms. TomTom will provide the Chinese smartphone manufacturer with mapping, live traffic data, and software on smartphones and tablets. TomTom spokesman Remco Meerstra confirmed to Reuters that the deal had been closed some time ago but had not been made public by the company. This comes as TomTom unveiled plans to move away from making navigation hardware and will focus more heavily on offering software services — making this a substantial step for TomTom and Huawei. While TomTom doesn’t quite match the global coverage and update speed of Google Maps, having a vital portion of it filled by a dedicated navigation and mapping firm is one step that might appease potential global Huawei smartphone buyers. There is no denying the importance of Google app access outside of China but solid replacements could potentially make a huge difference — even more so if they are recognizable by Western audiences. It’s unclear when we may see TomTom pre-installed on Huawei devices but we are sure that this could be easily added by way of an OTA software update. The bigger question remains if people are prepared to switch from Google Maps to TomTom for daily navigation. resource: https://9to5google.com/2020/01/20/huawei-tomtom/
  22. 2 points
    January 3, 2020 - Recent Landsat 8 Safehold Update On December 19, 2019 at approximately 12:23 UTC, Landsat 8 experienced a spacecraft constraint which triggered entry into a Safehold. The Landsat 8 Flight Operations Team recovered the satellite from the event on December 20, 2019 (DOY 354). The spacecraft resumed nominal on-orbit operations and ground station processing on December 22, 2019 (DOY 356). Data acquired between December 22, 2019 (DOY 356) and December 31, 2019 (DOY 365) exhibit some increased radiometric striping and minor geometric distortions (see image below) in addition to the normal Operational Land Imager/Thermal Infrared Sensor (OLI/TIRS) alignment offset apparent in Real-Time tier data. Acquisitions after December 31, 2019 (DOY 365) are consistent with pre-Safehold Real-Time tier data and are suitable for remote sensing use where applicable. All acquisitions after December 22, 2019 (DOY 356) will be reprocessed to meet typical Landsat data quality standards after the next TIRS Scene Select Mirror (SSM) calibration event, scheduled for January 11, 2020. Landsat 8 Operational Land Imager acquisition on December 22, 2019 (path 148/row 044) after the spacecraft resumed nominal on-orbit operations and ground station processing. This acquisition demonstrates increased radiometric striping and minor geometric distortions observed in all data acquired between December 22, 2019 and December 31, 2019. All acquisitions after December 22, 2019 will be reprocessed on January 11, 2020 to achieve typical Landsat data quality standards. Data not acquired during the Safehold event are listed below and displayed in purple on the map (click to enlarge). Map displaying Landsat 8 scenes not acquired from Dec 19-22, 2019 Path 207 Rows 160-161 Path 223 Rows 60-178 Path 6 Rows 22-122 Path 22 Rows 18-122 Path 38 Rows 18-122 Path 54 Rows 18-214 Path 70 Rows 18-120 Path 86 Rows 24-110 Path 102 Rows 19-122 Path 118 Rows 18-185 Path 134 Rows 18-133 Path 150 Rows 18-133 Path 166 Rows 18-222 Path 182 Rows 18-131 Path 198 Rows 18-122 Path 214 Rows 34-122 Path 230 Rows 54-179 Path 13 Rows 18-122 Path 29 Rows 20-232 Path 45 Rows 18-133 After recovering from the Safehold successfully, data acquired on December 20, 2019 (DOY 354) and from most of the day on December 21, 2019 (DOY 355) were ingested into the USGS Landsat Archive and marked as "Engineering". These data are still being assessed to determine if they will be made available for download to users through all USGS Landsat data portals. source: https://www.usgs.gov/land-resources/nli/landsat/january-3-2020-recent-landsat-8-safehold-update
  23. 2 points
    just found this interesting articles on Agisoft forum : source: https://www.agisoft.com/forum/index.php?topic=7851.0
  24. 2 points
    one of my favorite image hosting, , this is their announcement : Rest in Peace TinyPic
  25. 2 points
    not necessary to excel environment but : https://github.com/orbisgis/h2gis/wiki/4.2-LibreOffice
  26. 1 point
    The United States Space Force’s GPS III program reached another milestone with the successful core mate of GPS III Space Vehicle 08 at Lockheed Martin’s GPS III Processing Facility in Waterton, Colorado, April 15. With core mate complete, the space vehicle was named in honor of NASA trailblazer and “hidden figure” Katherine Johnson. The two-day core mate consisted of using a 10-ton crane to lift and complete a 90-degree rotation of the satellite’s system module, and then slowly lowering the system module onto the satellite’s vertical propulsion core. The two mated major subsystems come together to form an assembled GPS III space vehicle. Despite the COVID-19 pandemic, the Space and Missile Systems Center (SMC) and its mission partner Lockheed Martin ensured that SV08 core mate took place, in accordance with all Centers for Disease Control and local guidelines to minimize exposure or transmission of COVID-19. The GPS III Processing Facility’s cleanroom high bay was restricted to only key personnel directly supporting the operation. “Core mate is the most critical of the GPS space vehicle single-line-flow operations,” said Lt. Col. Margaret Sullivan, program manager and materiel lead for the GPS III program. “Despite the restrictions presented by the COVID-19 pandemic, our team adapted and worked tirelessly to achieve this essential milestone.” Katherine Johnson. When the core mate operation is successfully completed, a GPS III satellite is said to be “born.” In keeping with the team’s tradition of naming GPS III satellites after famous explorers and pioneers, SV08 was named “Katherine Johnson” in honor of the trailblazing NASA mathematician and “human computer” who designed and computed orbital trajectories for NASA’s Mercury, Apollo and space shuttle missions. One of four African-American women at the center of the nonfiction book by Margot Lee Shetterly and the movie Hidden Figures, Johnson was awarded the Presidential Medal of Freedom in 2015 for her groundbreaking contributions to the U.S. space program. Other GPS III satellites have been named in honor of explorers including GPS III SV01 “Vespucci” after Amerigo Vespucci; GPS III SV02 “Magellan” after Ferdinand Magellan; and GPS III SV03 “Columbus” after Christopher Columbus. Next up, performance tests. The next step for the newly christened “Katherine Johnson” is the post-mate Systems Performance Test (SPT) scheduled to begin in August. SPT electrically tests the performance of the satellite during the early phase of build and provides a baseline test data set to be compared to post-environmental test data. GPS III SV08 is currently scheduled to launch in 2022. GPS III is the most powerful GPS satellite ever developed. It is three times more accurate and provides up to eight times improved anti-jamming capability over previous GPS satellites on orbit. GPS III brings new capabilities to users as a fourth civilian signal (L1C), designed to enable interoperability between GPS and international satellite navigation systems, such as Europe’s Galileo system. GPS III satellites will also bring the full capability of the Military Code (M-code) signal, increasing anti-jam resiliency in support of the warfighter. These continued improvements and advancements to the GPS system makes it the premier space-based provider of positioning, navigation, and timing services for more than four billion worldwide. GPS III SV03 to Launch June 30. Launched in December 2018 and August 2019, GPS III SV01 and SV02 became part of today’s operational constellation of 31 satellites, on January 13 and April 1, 2020 respectively. GPS III SV03 is scheduled to launch on June 30. The SMC, located at the Los Angeles Air Force Base, California, is the center of excellence for acquiring and developing military space systems. Its portfolio includes the GPS, military satellite communications, defense meteorological satellites, space launch and range systems, satellite control networks, space based infrared systems, and space situational awareness capabilities. source: https://www.gpsworld.com/gps-iii-sv-08-born-with-core-mate-complete-named-katherine-johnson/
  27. 1 point
    GRASS GIS was, for a long time, something I dismissed as ‘too complex’ for my everyday geospatial operations. I formulated any number of excuses to work around the software and could not be convinced it had practical use in my daily work. It was ‘too hard to set-up’, ‘never worked well with QGIS’, and ‘made my scripting processes a nightmare’. In this example we will: part 1: 1. Download a small piece of elevation data from the LINZ Data Service 2. Build a GRASS environment to process these data 3. Build a BASH script to process the catchments 4. Import the elevation into the GRASS environment 5. Perform some basic GRASS operations (fill and watershed) 6. Export raster format for viewing 7. Export the vector catchments to shapefile part 2: 1. Creating multiple watershed boundaries of different sizes with GRASS and using a basic loop in BASH for the process. 2. Clipping the original raster by the watershed boundaries using GDAL and SQL with a basic loop in BASH. links: part 1: https://xycarto.com/2020/05/03/basic-grass-gis-with-bash/ part 2: https://xycarto.com/2020/05/05/basic-grass-gis-with-bash-plus-gdal/ source code: https://github.com/xycarto/xycarto_code/tree/master/scripts/grass/GRASS_BASH_blog
  28. 1 point
    6x open positions (as of 24.04.2020) French site (simple put "GIS" or "Swisstopo" in the search area) https://www.stelle.admin.ch/stelle/fr/home/stellen/stellenangebot.html German https://www.stelle.admin.ch/stelle/de/home/stellen/stellenangebot.html
  29. 1 point
    recently founded this : how to install brewer in arcmap 10 https://frew.eri.ucsb.edu/private/ESM263/week/2/Using_ColorBrewer_with_ArcMap_10.html
  30. 1 point
    For those who were looking for a style editor like Mapbox for Esri basemaps, here is one. This is an interactive basemap style WYSIWYG editor readily usable with ArcGIS Developer account. How it works Start by selecting an existing Esri vector basemap (e.g. World Street Map or Light Gray Canvas) and then just begin customizing the layer colors and labels from there. You can edit everything from fill and text symbols to fonts, halos, patterns, transparency, and zoom level visibility. When you are finished, the styles are saved as an item in ArcGIS Online with a unique ID. The Map Viewer or any custom application can then reference the item to display the basemap. Design Tools The editor makes styling easy by allowing you to style many layers at once or by allowing you to search for individual layers of interest. Here are some of options available: Quick Edit – select all layers and style them at once Edit by Color – select and replace a color for one or more layers Edit Layer Styles – search for one or more layers to style Layer Editor – click the map or the layer list to perform detailed editing on a layer Quick edits Layer editor Try it! To start customizing a basemap sign into the ArcGIS for Developers website and click “New Basemap Style”. There are also new ArcGIS DevLabs for styling a vector tile basemap and displaying a styled vector basemap in your application. For more inspiration visit this showcase of some custom styles we have created. ArcGIS Vector Tile Style Editor
  31. 1 point
    A possible design flaw has surfaced by DJI Mavic Mini owners experiencing the propellers rubbing against the drone‘s body due to the lightweight and flexible design of the arms. It looks to be a known problem with people already working on fixes for it. Images have appeared on DJI’s community website with a user posting images of their Mavic Mini with what looks be marks caused by the propellers contacting the body. The user had shared that they recently started to notice the front set of propellers tend to hit the drone body, even if new ones were put on. He also stated it was more likely to happen when the drone is in sport mode. It looks like the cause of the problem is the flexibility in the arms used due to the weight restrictions DJI was able to keep within. The arms can flex due to the torque of the motors, causing the propellers to get closer to the drone body, and therefore rub against it. It looks to be a known problem for some as a company has already produced prop mounts that raise the height of the propellers just enough to clear the body fully. There are also designs on Thingeverse that replace the soft foam inserts in the arms with stiff 3D printed plastic. Both of these options will likely set the Mavic Mini over the 250-gram weight limit. source: https://dronedj.com/2020/03/24/dji-mavic-mini-design-flaw-pops-hit-done-body/
  32. 1 point
    https://support.micasense.com/hc/en-us/articles/115000831714-How-to-Process-MicaSense-Sensor-Data-in-Pix4D and https://support.micasense.com/hc/en-us/article_attachments/360036645134/Pix4D_to_Analysis.pdf
  33. 1 point
    sorry i cant see your picture, our country block imgur, really suck 😷
  34. 1 point
    Simple Analysis of Vegetative Trends in Earth Engine - SAVETREE - is a tool developed in Google Earth Engine for the Lassen Volcanic National park, it estimates tree mortality by fitting a linear trend to time serries data of a user chosen spectral index. The user can export their new map in the form of TIFF files,add historic fire layers, and the user can produce graphs which view the values in the time series for a particular pixel by clicking on the layer. Running SAVETREE Hit the “run” button in the center panel to make the widget appear. Using SAVETREE the user can do the following things: * Spectral Index: Choose from NDMI, NDVI, NDWI or NBR to select which spectral index you would like to create a linear regression layer for. The default is NDMI. * Area of interest: Choose from Lassen Volcanic National Park, Lassen National Forest, DEVELOP T2 Study Area, the Badger Planning area or choose Your asset (below) to perform the analysis on an asset you load yourself see Loading an Asset for instructions on loading your own asset. The default is LVNP. * End year and duration: The year must be in YYYY format, it is the last year of the duration of the analysis. The duration should be a number less than 20, with the most meaningful results coming from 3-7 years, it is the number of years it will create the time series for. For example, if you put in 1990 and a duration of 3, the analysis will be run on 1988, 1989, and 1990. The defaults are 2016 and 5. * Add Coefficient map: Performs the coefficient trend map analysis on the spectral index and area of interest for the duration you supplied ending with the year you specified and adds that layer to the map. * Add Bivariate map: Performs the Bivariate map analysis on the spectral index and area of interest for the duration you supplied ending with the year you specified and adds that layer to the map. * Reset Map: Clears all layers. Note: it does not reset the area of interest or any items in the widget. To reset the area of interest, choose a different area of interest from the dropdown before running a new analysis. * Fire history start and end years: These years must be in YYYY format. These numbers create a filter for the fire history data where the only data to be added to the map will be fires or treatments that occurred during those years. * Fire History Dataset: Select from FRAP Statewide Wildfire Dataset, RX fire, Other treatment, or load your own fire data asset. To load your own asset see Loading an Asset. The wildfire, rx fire and other treatments are FRAP datasets, for more details on the FRAP data and for the most up-to-date data sets please go to http://frap.fire.ca.gov/projects/fire_data/fire_perimeters_index * Export Coefficient Map: Exports the Coefficient trend layer as a TIFF file. See Exporting a Layer to get details on how to export layers to your Google Drive. * Export Bivariate Map: Exports the Bivariate map layer as a TIFF file. See Exporting a Layer to get details on how to export layers to your Google Drive. * Change Inspector: Click on any part of the Coefficient Trend or Bivariate Map layers and a graph of the change during each year for your duration for that particular point will appear at the bottom of the widget. Click the little box with the arrow in the upper right hand corner of the graph to open the graph in a new tab. You can download this graph from this new tab. SAVETREE was developed over two terms with DEVELOP: * Authors v1.0: Joshua Verkerke, Anna McGarrigle, John Dilger * Authors v2.0: Heather Myers, Anna McGarrigle, Peter Norton, Andrea Ferrer Download code
  35. 1 point
    The Gridded Population of the World (GPW) collection, now in its fourth version (GPWv4), models the distribution of human population (counts and densities) on a continuous global raster surface. Since the release of the first version of this global population surface in 1995, the essential inputs to GPW have been population census tables and corresponding geographic boundaries. The purpose of GPW is to provide a spatially disaggregated population layer that is compatible with data sets from social, economic, and Earth science disciplines, and remote sensing. It provides globally consistent and spatially explicit data for use in research, policy-making, and communications. For GPWv4, population input data are collected at the most detailed spatial resolution available from the results of the 2010 round of Population and Housing Censuses, which occurred between 2005 and 2014. The input data are extrapolated to produce population estimates for the years 2000, 2005, 2010, 2015, and 2020. A set of estimates adjusted to national level, historic and future, population predictions from the United Nation’s World Population Prospects report are also produced for the same set of years. The raster data sets are constructed from national or subnational input administrative units to which the estimates have been matched. GPWv4 is gridded with an output resolution of 30 arc-seconds (approximately 1 km at the equator). The nine data sets of the current release are collectively referred to as the Revision 11 (or v4.11) data sets. In this release, several issues identified in the 4.10 release of December 2017 have been corrected as follows: The extent of the final gridded data has been updated to a full global extent. Erroneous no data pixels in all of the gridded data were recoded as 0 in cases where census reported known 0 values. The netCDF files were updated to include the Mean Administrative Unit Area layer, the Land Area and Water Area layers, and two layers indicating the administrative level(s) of the demographic characteristics input data. The National Identifier Grid was reprocessed to remove artefacts from inland water. In addition, two attributes were added to indicate the administrative levels of the demographic characteristics input data, and the data set zip files were corrected to include the National Identifier Polygons shapefile. Two new classes (Total Land Pixels and Ocean Pixels) were added to the Water Mask. The administrative level names of the Greece Administrative Unit Centre Points were translated to English. Separate rasters are available for population counts and population density consistent with national censuses and population registers, or alternative sources in rare cases where no census or register was available. All estimates of population counts and population density have also been nationally adjusted to population totals from the United Nation’s World Population Prospects: The 2015 Revision. In addition, rasters are available for basic demographic characteristics (age and sex), data quality indicators, and land and water areas. A vector data set of the centrepoint locations (centroids) for each of the input administrative units and a raster of national level numeric identifiers are included in the collection to share information about the input data layers. The raster data sets are now available in ASCII (text) format as well as in GeoTIFF format. Five of the eight raster data sets are also available in netCDF format. In addition, the native 30 arc-second resolution data were aggregated to four lower resolutions (2.5 arc-minute, 15 arc-minute, 30 arc-minute, and 1 degree) to enable faster global processing and support of research communities that conduct analyses at these resolutions. All of these resolutions are available in ASCII and GeoTIFF formats. NetCDF files are available at all resolutions except 30 arc-second. All spatial data sets in the GPWv4 collection are stored in geographic coordinate system (latitude/longitude).
  36. 1 point
    really nice, is it possible to leverage into forecast? that would be interesting
  37. 1 point
    I have a project with autocad files fire up my Workstation Laptop (Dell Precission 5510) and load CAD data. Holly cr*p, this software run like a snail, 🤣 try to disable Hardware acceleration, yeah much better experience, but still laggy as old Arcgis Pro beta 😂 searching around and found this article: https://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/Optimize-Performance-within-Windows-7-Environments.html?_ga=2.205082898.303799305.1579712200-1066991414.1579712200 didnt have time to try all the suggestion yet, but, hey all GISArea members, do you use Autocad? how to improve your CAD Experience? share with me, 😉
  38. 1 point
    While many advancements have been made this last decade in automated classification of above surface features using remote sensing data, progress for detecting underground features has lagged in this area. Technologies for detecting features, including ground penetrating radar, electrical resistivity, and magnetometry exist, but methods for feature extraction and identification mostly depend on the experience of instrument user. One problem has been creating approaches that can deal with complex signals. Ground penetrating radar (GPR), for instance, often produces ambiguous signals that can have a lot different noise interference relative to the feature one wants to identify. One approach has been to apply approximation polynomials to classify given signals that are then inputs for an applied neural networks model using derived coefficients. This technique can help reduce noise and differentiate signals that follow clear patterns that vary from larger background signals. Differentiation of signals based on minimized coefficients are one way to simplify and better differentiate data signals.[1] Another approach is to use multilayer perceptron that has a nonlinear activation function which transforms the data. This is effectively a similar technique but uses different transform functions than other neural network models. Applications of this approach include being able to differentiate thickness of underground structures from surrounding sediments and soil.[2] Other methods have been developed to determine the best location to place source and receivers that can capture relevant data. In seismic research, the use of convolutional neural networks (CNNs) has been applied to determine better positioning of sensors so that better data quality can be achieved. This has resulted in very high precision and recall rates at over 0.99. Using a series of filtered layers, signals can be assessed for their data quality with that of manually placed instruments. The quality of the placement can also be compared to other locations to see if the overall signal capture improves. Thus, rather than focusing on mainly signal processing, this method also focuses on signal placement and capture that compares to other placements to optimize data capture locations.[3] One problem in geophysical data is inversion, where data points are interpreted to be the opposite of what they are due to a reflective signal that may hid the nature of the true data. Techniques using CNNs have also been developed whereby the patterning of data signals around a given inversion can be filtered and assessed using activation functions. Multiple layers that transform and reduce data to specific signals helps to identify where patterns of data suggest an inversion is likely, while checking if this follows patterns from other data using Bayesian learning techniques.[4] source: https://www.gislounge.com/automated-remote-sensing-of-underground-features/
  39. 1 point
    Interesting articles : North-South displacement field - 1999 Hector-Mine earthquake, California In complement to seismological records, the knowledge of the ruptured fault geometry and co-seismic ground displacements are key data to investigate the mechanics of seismic rupture. This information can be retrieved from sub-pixel correlation of optical images. We are investigating the use of SPOT (Satellite pour l'Observation de la Terre) satellites images. The technique developed here is attractive due to the operational status of a number of optical imaging programs and the availability of archived data. However, uncertainties on the imaging system itself and on its attitude dramatically limit its potential. We overcome these limitations by applying an iterative corrective process allowing for precise image registration that takes advantage of the availability of accurate Digital Elevation Models with global coverage (SRTM). This technique is thus a valuable complement to SAR interferometry which provides accurate measurements kilometers away from the fault but generally fails in the near-fault zone where the fringes get noisy and saturated. Comparison between the two methods is briefly discussed, with application on the 1992 Landers earthquake in California (Mw 7.3). Applications of this newly developped technique are presented: the horizontal co-seismic displacement fields induced by the 1999 Hector-Mine earthquake in California (Mw 7.1) and by the 1999 Chichi earthquake in Taiwan (Mw 7.5) have recently been retrieved using archive images. Data obtained can be downloaded (see further down) Latest Study Cases Sub-pixel correlation of optical images Following is the flow chart of the technique that as been developped. It allows for precise orthorectification and coregistration of the SPOT images. More details about the optimization process will be given in the next sections. Understanding the disparities measured from Optical Images Differences in geometry between the two images to be registered: - Uncertainties on attitudes parameters (roll, pitch, yaw) - Inaccuracy on orbital parameters (position, velocity) - Incidence angle differences + topography uncertainties (parallax effect) - Optical and Electronic biases (optical aberrations, CCD misalignment, focal length, sampling period, etc… ) » May account for disparities up to 800 m on SPOT 1,2,3,4 images; 50m for SPOT 5 (see [3]). Ground deformations: - Earthquakes, land slides, etc… » Typically subpixel scale: ranging from 0 to 10 meters. Temporal decorrelation: - Changes in vegetation, rivers, changes in urban areas, etc… » Correlation is lost: add noise to the measurement – up to 1m. » Ground deformations are largely dominated by the geometrical artifacts. Precise registration: geometrical corrections SPOT (Systeme pour l'Observation de la Terre) satellites are pushbroom imaging systems ([1],[2]): all optical parts remain fixed during acquisition and the scanning is accomplished by the forward motion of the spacecraft. Each line in the image is then acquired at a different time and submitted to the different variations of the platform. The orthorectification process consists in modeling and correcting these variations to produce cartographic distortion free images. It is then possible to accurately register images and look for their disparities using correlation techniques. Attitude variations (roll, pitch, and yaw) during the scanning process have to be integrated in the image model (see [1],[2]). Errors in correcting the satellite look directions will result in projecting the image pixels at the wrong location on the ground: important parallax artifacts will be seen when measuring displacement between two images. Exact pixel projection on the ground is achieved through an optimization algorithm that iteratively corrects the look directions by selecting ground control points. An accurate topography model has to be used. What parameters to optimize? - Initial attitudes values of the platform (roll, pitch, yaw), - Constant drift of the attitude values along the image acquisition, - Focal length (different value depending on the instrument , HRG1 – HRG2), - Position and velocity. How to optimize: Iterative algorithm using a set of GCPs (Ground Control Points). GCPs are generated automatically with a subpixel accuracy: they result from a correlation between an orthorectified reference frame and the rectified image whose parameters are to be optimized. A two stages procedure: - One of the image is optimized with respect to the shaded DEM (GCP are generated from the correlation with the shaded DEM). The DEM is then considered as the ground truth. No GPS points are needed. - The other image is then optimized using another set of GCP resulting from the correlation with the first image (co-registration). Measuring co-seismic deformation with InSAR, a comparison A fringe represents a near-vertical displacement of 2.8 cm SAR interferogram (ERS): near-vertical component of the ground displacement induced by the 1992 Landers earthquake [Massonnet et al., 1993]. No organized fringes in a band within 5-10 km of the fault trace: displacement sufficiently large that the change in range across a radar pixel exceeds one fringe per pixel, coherence is lost. http://earth.esa.int/applications/data_util/ndis/equake/land2.htm » SAR interferometry is not a suitable technique to measure near fault displacements The 1992 Landers earthquake revisited: Profile in offsets and elastic modeling show good agreement From: [6] - Measuring earthqakes from optical satellite images, Van Puymbroeck, Michel, Binet, Avouac, Taboury - Applied Optics Vol. 39, No 20, 10 July 2000 Other applications of the technique, see [4], [5]. » Fault ruptures can be imaged from this technique Applying the precise rectification algorithm + subpixel correlation: The 1999 Hector-Mine earthquake (Mw 7.1, California) Obtaining the Data (available in ENVI file Format. Load banbs as gray scale images. Bands are: N/S offsets, E/W offsets, SNR): Raw and filtered results: HectorMine.zip Pre-earthquake image: SPOT 4, acquisition date: 08-17-1998 Ground resolution: 10m Post-earthquake image: SPOT 2, acquisition date: 08-18-2000 Ground resolution: 10m Offsets measured from correlation: Correspond to sub-pixel offsets in the raw images. Correlation windows: 32 x 32 pixels 96m between two measurements So far we have: - A precise mapping of the rupture zone: the offsets field have a resolution of 96 m, - Measurements with a subpixel accuracy (displacement of at most 10 meters), - Improved the global georeferencing of the images with no GPS measurements, - Improved the processing time since the GCP selection is automatic, - Suppressed the main attitude artifacts. The profiles do not show any long wavelength deformations (See Dominguez et al. 2003) We notice: - Linear artifacts in the along track direction due to CCD misalignments, Schematic of a DIVOLI showing four CCD linear arrays. - Some topographic artifacts: the image resolution is higher than the DEM one, - Several decorrelations due to rivers and clouds, - High frequency noise due to the noise sensitivity of the Fourier correlator (See Van Puymbroeck et al.). Conclusion Subpixel correlation technique has been improved to overcome most of its limitations: » Precise rectification and co-registration of the images, » No more topographic effects (depending on the DEM resolution), » No need for GPS points – independent and automatic algorithm, » Better spatial resolution (See Van Puymbroeck et al.) To be improved: » Stripes due to the CCD’s misalignment, » high frequency noise from the correlator, » Process images with corrupted telemetry. » The subpixel correlation technique appears to be a valuable complement to SAR interferometry for ground deformation measurements. References: [1] SPOT 5 geometry handbook: ftp://ftp.spot.com/outgoing/SPOT_docs/geometry_handbook/S-NT-73-12-SI.pdf [2] SPOT User's Handbook Volume 1 - Reference Manual: ftp://ftp.spot.com/outgoing/SPOT_docs/SPOT_User's Handbook/SUHV1RM.PDF [3] SPOT 5 Technical Summary ftp://ftp.spot.com/outgoing/SPOT_docs/technical/spot5_tech_slides.ppt [4] Dominguez S., J.P. Avouac, R. Michel Horizontal co-seismic deformation of the 1999 Chi-Chi earthquake measured from SPOT satellite images: implications for the seismic cycle along the western foothills of Central Taiwan, J. Geophys. Res., 107, 10 1029/2001JB00482, 2003. [5] Michel, R. et J.P., Avouac, Deformation due to the 17 August Izmit earthquake measured from SPOT images, J. Geophys. Res., 107, 10 1029/2000JB000102, 2002. [6] Van Puymbroeck, N., Michel, R., Binet, R., Avouac, J.P. and Taboury, J. Measuring earthquakes from optical satellite images, Applied Optics Information Processing, 39, 23, 3486–3494, 2000. Publications: Leprince S., Barbot S., Ayoub F., Avouac, J.P. Automatic, Precise, Ortho-rectification and Co-registration for Satellite Image Correlation, Application to Seismotectonics. To be submitted. Conferences: F Levy, Y Hsu, M Simons, S Leprince, J Avouac. Distribution of coseismic slip for the 1999 ChiChi Taiwan earthquake: New data and implications of varying 3D fault geometry. AGU 2005 Fall meeting, San Francisco. M Taylor, S Leprince, J Avouac. A Study of the 2002 Denali Co-seismic Displacement Using SPOT Horizontal Offsets, Field Measurements, and Aerial Photographs. AGU 2005 Fall meeting, San Francisco. Y Kuo, F Ayoub, J Avouac, S Leprince, Y Chen, J H Shyu, Y Kuo. Co-seismic Horizontal Ground Slips of 1999 Chi-Chi Earthquake (Mw 7.6) Deduced From Image-Comparison of Satellite SPOT and Aerial Photos. AGU 2005 Fall meeting, San Francisco. source: http://www.tectonics.caltech.edu/geq/spot_coseis/
  40. 1 point
    I am enthusiastic how I can create extension same as GIS.XL for LibreOffice instead of Microsoft Excel!? I am going to know where should I start? http://www.gisxl.com/Features The GIS.XL add-in provides features and functions for work with spatial data directly inside the Excel environment. Add-in includes a standard interface, familiar from other GIS programs - Map and Legend. Combine Excel (tabular data) and spatial (map) data in layers.
  41. 1 point
    This is the real challenges for Huawei how to convince their user to use this new operating system. But nothing is impossible...
  42. 1 point
    Klau Geomatics has released Real-Time Precise Point Positioning (PPP) for aerial mapping and drone positioning that enables 3 to 5 cm initial positioning accuracy, anywhere in the world, without any base station data or network corrections. With this, you Just need to fly your drone at any distance, anywhere. The system allows to navigate with real-time cm level positioning or geotag your mapping photos and Lidar data. You don’t need to think about setting up a base station, finding quality CORS data or setting up an RTK radio link. You don’t need to be in range of a CORS station, you can fly autonomously, in remote areas, long corridors, unlimited range, it just works, giving you centimetre level accuracy, anywhere. Now, with this latest satellite-based positioning technology, 3 to 5cm accuracy can be achieved, anywhere in the world, with no base station. KlauPPP leverages NovAtel’s industry-leading technology to achieve this quantum leap in PPP accuracy. NovAtel PPP and Klau Geomatics hardware/software system is now the simplest, most convenient and accurate positioning system for UAVs and manned aircraft. The bundled solution enables accurate positioning in any published or custom coordinate system and datum. This technology is very applicable to surveying, mapping, navigation and particularly the emerging drone inspection industry, starting to realize that absolute accuracy is essential to analyze change over time in 3D assets. A BVLOS parcel delivery drone can now travel across a country and arrive exactly on it’s landing pad. No range limitations, no base station requirements or radio links. Highly accurate autonomous flight. Large scale enterprise drone companies can deploy their fleet of operators with a simple, mechanical workflow to capture accurate, repeatable data, without the complications of the survey world; of RTK radio links and network connections or logging base station data within a range of each of their many projects. Now they have a simple consistent operation that just works, every time, every location. “Just as Klau Geomatics led the industry from RTK and GCPs to PPK, we now lead the charge to PPP as the next technology for simple, accurate drone operations”, says Rob Klau, Director of Klau Geomatics source : http://geomatics.com.au/
  43. 1 point
    Hi Darksabersan, the links are dead, could you reactivate and perhaps upload to a different site like Mega.nz, please? thanks
  44. 1 point
    TopoMapCreator (beta) A set of GIS tools that helps creating topographic map TopoMapCreatorThe TopoMapCreator consists of of 5 Programs: MapCreator, GeoToolsCmd, TopoMap, EcwToMobile and ExtendedMapCreator. More information for example about how to install it, you find under TopoMapCreator. Now read, what the 5 Programs are doing: 1. ExtendedMapCreatorExtendedMapCreator is a Desktop-Program, that creates "Topographic Maps" from OSM, NASA and ESA. You simply define a map extent by dragging over a browsable word map, click on start and wait till the GeoTIFF, ECW, GALILEO, ORUXMAPS or NAVIMAP files got created. ExtendedMapCreator is based on the Mapnik-Renderer, nevertheless all data downloading and processing is fully automatic. Click on ExtendedMapCreator to read more about the Program! 2. MapCreatorMapCreator is a GIS toolset. The tools have the common goal to create Topographic Maps. Currently it consists of 10 tools: The GeoreferencingTool georeferences scanned map series. The EcwHillshaderTool adds hillshades to a map. The SrtmHillshadesTool creates hillshades. The EcwToMobileTool converts a map to a Smartphone App Format. The GeonamesToShapeTool creates a shapefile from a GeoNames file. The ShapeToOsmTool creates an OSM file from shapefiles. The WarpEcwTool warps (reprojects) huge maps. The RussianMapsCreatorTool downloads and processes Russian maps. The QgisToEcwTool makes a Print-Screen of a qGis view. The USGSTopoMapTool downloads and processes USGS maps. Click on any of the tools to know more about it! 3. GeoToolsCmdGeoToolsCmd provides the same GIS toolset as the MapCreator, but accessible over the Command-Prompt. With GeoToolsCmd it is possible to write batch files. 4. TopoMapTopoMap is simple Desktop-Program to download specific Maps. 5. EcwToMobileEcwToMobile is a simple Desktop-Program to convert an ECW file to a Mobile App Format. The program is redundant to the EcwToMobileTool. darksabersan.
  45. 1 point
  46. 1 point
    Which WEBGIS Software can be used with Google Cloud??
  47. 1 point
    The Klencke Atlas is one of the world's biggest: it measures 176 x 231 cm when open. It takes its name from Joannes Klencke, who presented it to Charles II on his restoration to the British thrones in 1660. Its size and its 40 or so large wall maps from the Golden Age of Dutch mapmaking were supposed to suggest that it contained all the knowledge in the world. At another level, it was a bribe intended to spur the King into granting Klencke and his associates trading privileges and titles. Charles, who was a map enthusiast, appreciated the gift. He placed the atlas with his most precious possessions in his cabinet of curiosities, and Klencke was knighted. Later generations have benefited too. The binding has protected the wall maps which have survived for us to enjoy - unlike the vast majority of other wall maps which, exposed to light, heat and dirt when hung on walls, have crumbled away. visit : https://www.bl.uk/collection-items/klencke-atlas
  48. 1 point
    I getting some images of a oil palm estate taken from a DIY drone. The image is stitch and mosaic. Has anyone done automated tree counting on these images. Seen some examples using eCognition but that was with multi-spectral images.
  49. 1 point
    look at maxmax website, they do NIR conventions on cameras that can fit on drones. Did a canon compact with them 100%. Try imageJ (free software), run the NDVI settings you will get some data. Or use a blue filter on your camera, you will get usable images for NDVI. I got good data with dessert palms from RGB images in eCognition, but you have o play with the analysis a bit! Having a NIR layer will make life easy for you. Good Luck
  50. 1 point
    If you have a very-high resolution image (< 1m ) and it has only 3 spectral bands in the visible spectrum (Red, Green, Blue - RGB) with no additional infrared bands (NIR), the best option to extract trees is to use an OBIA method ( > eCognition is one of the best OBIA softwares). So, for your task, me I would use eCognition.


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