Jump to content

Our forum made possible by displaying online advertisements to our visitors.

Please consider supporting us by disabling your ads blocker.

Arhanghelul

Members
  • Content count

    347
  • Joined

  • Last visited

  • Days Won

    10

Arhanghelul last won the day on September 25 2016

Arhanghelul had the most liked content!

Community Reputation

119 Famous

1 Follower

About Arhanghelul

  • Rank
    Lecturer

Profile Information

  • Gender
    Male
  • Location
    Kingdom of Heaven (RO, east Europe)
  • Interests
    NIHIL SINE DEO ET .....GIS ! :)
  1. Gatewing - Photogrametry Tech

    Yes, I know that my question has no connection to your topic. But i was curious to know: what methods/softwares do you use for semi-automatic/vectorizing and image post-processing ?
  2. Gatewing - Photogrametry Tech

    What about image processing softwares ? Drones/UAV sistems produce a large volume of information (optical images, LIDAR, etc). For example, how do you extract all the elements from a large orthomosaic over an urban area or a less complex landscape (forest & built up areas) ? Manual vectorization or semi/automatic vectorization ?
  3. Where to download historical SPOT imagery?

    In EarthExplorer i see that SPOT 1-4 archive images are free to download only for US, but for Europe are not. So, is there another way to search and download the SPOT 1-4 archive satellite images for Europe ?
  4. Question: Where can I find and donwload free SPOT satelite images ? I have read a year ago that the SPOT1-4 archive will be free, similar to Landsat archive. What is the status for SPOT images ? Download links for SPOT ?
  5. Landsat 9 Will Launch 2020

    I don't think so. If satellite imagery with <2 m in spatial resolution would be free to download like Landsat, then private company like DigitalGlobe, Aibuse and others what they will sell to coustomers ?
  6. ERDAS vs ENVI

    And remember that you will also need to learn how to use the softwares. eCognition Developer it has a lot of algorithms and functions, good for change detection using high resolution images (under 5 m, from commercial satellites and images from UAV/drones).
  7. 260/250 mb/s This is almost half of the maximum speeds of my ADATA Pro SP550 series SSD, because my laptop mainboard is limited to max. 3Gb/s. But still, is much faster compared to my HDD...
  8. I have just replaced my 320 GB HDD-drive 5400 rpm with a 240 SSD from ADATA in my leptop. Now the multiresolution segmentation algorithm in eCognition Developper is working better, is much more faster and the maximum image size to process has increased from 4000x4000 pixels to 7000x7000 pixels (I am using the same CPU and RAM configuration). So, now i see that SSD's are more efficient thant classic HDD's.
  9. Orthorectification Step by Step

    Where do you have ERDAS 2016 ? Share a download link, please.
  10. Hello ! I would like to know what would be the best and the medium PC configuration required to run eCognition Developer in good performance. I read on eCognition forum that this software needs a lot of RAM memory, especially when we use the Multiresolution segmentation algorithm (MRS). It also needs a good CPU and plenty of hard drive space on the computer. These problems can be solved by using eCognition Server, but most of us have a crack license only for eCognition Developer. So we are limited to the performance of our PC's. I am looking to buy a new PC and I would like to know what would be the best configuration to run eCognition Developer in good performance. Can you give me some general tips ? What CPU to use (Intel, AMD, Gz) ? Mainboard, the type and the RAM producer ? HDD or SSD ? My budget: @1500 USD (without the LCD monitor or any other peripherals parts) Thanks, my friends !
  11. Where can I find some international online GIS & Remote Sensing courses organized by institutions or companies that issue graduation diplomas for their students ? Thank you !
  12. extraction of built-up area from images

    Maybe there is a problem of content of moisture in the soil that makes buildings and soil very similar, so maybe you should select another Landsat scene from a dry season. Have you tested with another Landsat scene for your area of interest ?
  13. extraction of built-up area from images

    NDBI = Normalized Difference Built-up Index search the formula for Landsat in Google You can't escape the problem of mixt pixels between built-up and bare soil. These 2 elements have similar spectral signatures. You can only maximize the spectral differentiation by using derivates like NDVI, NDBI, NDWI, etc.... as aditional bands in Landsat scene classification. There is some other supervised methos to better separate the elements, like Spectral Angle Mapper (SAM) , etc, etc. search on internet and on ENVI help page, on sub-pixel classification methos. Another method is to use OBIA > eCognition. OBIA is based on image segmentation. Segmentation is grouping similar spectral pixels into objects. Then you classify these pixel groups based on their spectral signature, shape, area, texture, position into the image, etc. OBIA is similar to visual image interpretation and classification But some research articles say that OBIA is inferior to traditional per-pixel classification methods (supervised and unsupervised) in the case of medium and low spatial resolution images like Landsat, ASTER, SPOT 1-4, MODIS, etc. OBIA works better on high-resolution images like WorldView-2&3, Quickbird, Pleiades, IKONOS, orthophotos, etc (<5 m spatial resolution). These images are much better for built-up area extraction compared to Landsat. So, in your case, my friend, it depends on the accuracy of the classification that you want to obtain !
  14. How to classify polygons by shape?

    This is an interesting topic. I have also asked myself how to integrate landscape metrics into eCognition to classify different building shapes in urban areas from high-resolution images and to estimate the degree of urban landscape fragmentation. If someone has a solution to this problem, please share !
  15. UAV sensor

    I have found this: https://event38.com/product/custom-ngb-filter-glass-for-diy-camera-conversion/ and this: http://mosaicmill.com/products/hardware/NDVI-cameras.html?gclid=CLeNrpGHu8wCFTUW0wodsJoPaQ and this: http://www.mapir.camera/blogs/news/49522051-the-leaf-filter-test Who is using one of the filters to his UAV ?
×

Important Information

By using this site, you agree to our Terms of Use.