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  1. Eternal fascination of the satellites.... You cannot penetrate hundreds and thousands of meters of water with an actual and reliable (from the satellite body) energy..... As an example the light from the sun is completely adsorbate after something, perhaps around a hundred meters. At the moment they are some methods of investigation, from an airborne platform by a special LIDAR, Green LIDAR.... But only for the near shore areas...... PS. I am seeing a demand like this: "I want to undertake a study concerning old prospecting using satellite data. Was requesting more information in regard to the same." Keep in mind, the satellites (some) are offering only some clues for prospective areas. No gold or diamonds mines, just like that, jumping from a satellite data package....
  2. @rahmansunbeam Thanks for the tip. I will check..... The project is not available now, long market story. But I know the place by heart..... That hole after the ridge was a nightmare for me because of a critical chain of exclusion ( a pipe, crossing the mountains, at a limited angle, a maximum elevation, etc). But as I wrote before, I made some merges of the two data sets SRTM and ASTER. The result was something like a smallpox affected skin, but with a perfect rectangular pattern. Obvious a offset of the elevations. I observed this on large surfaces. Sorry to discard all, so I cannot say which one one was up and which down, I think I remember, something of meters order of magnitude, almost 10 m.
  3. Ambitious........ To merge SRTM and Aster.... Personally I worked with SRTM and ASTER somewhere in west Africa, near the Ecuador, - 2 latitude area. 5000 sqkm the biggest exploration permit. ASTER was full of artifacts, something like "small circular spots" (difficult to understand the origin, perhaps the clouds traces) and lines/shadows in a rectangles grid, probably the connections at the limit of the original data tiles, the swats. Also, big "holes" with more than 200 m elevation drop, almost vertical, from a mountain ridge. Not existing in SRTM; because it was a critical area, we checked with a "macete" team in the the jungle; no such huge hole there. Also it was a regular elevation offset, some goods meters among the datasets. Joining the grids I obtained largely a DEM showing me the relief, but full of spots (dots) in a regular grid. The dots were obvious generated by one of the grids, with an vertical offset.
  4. I think is related to the two main option for surfaces calculus from MI. They are exposed , as an example, at general settings in older MI: you have the option to calculate a surface in "cartesian" or "spherical" . In the new versions this is more hidden. In your case, I think that you are working in a long/lat system, perhaps WGS84; this one is entering in the so called spherical calculus, and you have this as implicit (the screen capture). The cartesian calculus are exposed as options. You must chose, evaluate carefully what you need, what you are targeting in the project. You will make unhappy an engineer if you are offering him a map with degrees... m.....seconds. In reverse, a sailor if you are offering him metric coordinates....
  5. Usually they are more..... In happy cases, from the state...Otherwise, a militia....
  6. Hi Paolo, Remember from my text: "collect around 200 l of alluvial, concentrate by panning, then carefully observe the heavy minerals associations". I saw some papers telling about 100 kg (the minimal I think). We were more conservative and prudent in some projects. It is a large quantity; depending on on the pan size, at least 10- 20 pans to wash. Finally, depending on the area, you will obtain some hundreds of grams of heavy minerals; among them, a lot without significance, like magnetite. And then, in less quantities: pyrope and eclogitic garnet, chrome diopside, picroilmenite, chromite; and, to a lesser extent, olivine . The indicators. These are the indicators about a kimberlite body. The kimberlite is decomposing fast and will leave this mineral traces in the alluvial, but diluted with other minerals, depending on the distance. It is what you are searching. Personal (from some sustained field experience, and also a lot of study for Remote Sensing or GIS) I don't think that you can discriminate those minerals, in such small quantities, basis on remote sensing, in alluvials. To few, in order to have a significant spectral signature. See an article, about the kimberlites* As a good help, starting from the satellite data, you can do a geomorphological analysis. Discriminate well and precise the hydrographic network, then to locate some favorable areas (terraces, dejection cones), for heavy minerals concentration. Among them, beside the indicators, you can find, or not, diamonds (3.52 SG). It is what I done, in my projects. Not Angola, but nearby. Then, to start exploring, as I wrote before, on the ground. Or direct mining, with the risks of acquiring heavy equipment and be without enough reserves. I don't know if you have an exclusive license; if yes, can you send me the coordinates, in order to see what it is available (satellite) for that area ? If you are prospecting, and the area is confidentially, please send something like an nearby area, one-two hundreds kilometers distance. They are some new satellite data and I want to see the confidence, if you are agreed. Regards, Iulian * http://www.hgimaging.com/PDF/Kruse_IEEE2000_Kimberlites.pdf "Higher spatial resolution data (1.6m AVIRIS and 4m HyMap acquired in 1998 and 1999, respectively) are being used to map additional detail. Poor exposures, vegetation cover, and weathering, however, make identification of characteristic kimberlite minerals difficult except where exposed by mining. "
  7. Hi Paolo Are you asking (or your employer) miracles from remote sensing, and especially with free resources, like LandSat. Have you check the cloud coverage in your target area ? You can identify only favorable areas (alluvial fields like meanders, cone shapes, etc). At the Landsat resolution will be difficult..... Then, quatre quatre pieds, meaning foots on the ground and sampling. It is a long process painful lounge and expensive: collect around 200 l of alluvial, concentrate by panning, then carefully observe the heavy minerals associations. A lot of samples like this...... Observation there in the field and also in specialized and expensive laboratories (they are experts specialized in heavy minerals microscopy). I am sure you know all these..... You can have/or not diamonds, or kimberlite indicator minerals. Keep in mind that perhaps only one of ten kimberlites bodies is "pregnant" with diamonds Regards, Iulian
  8. @Capricorn Perhaps you haven't understand. I am not giving data to other to post processing. Just sending people to work in the field according to our goals. I suppose also your urban planing layouts are put in place by some people, starting with the architects, engineers etc and finishing with the last shovel guy. I am returning to the definition: GIS.... Geographical Information Systems. That System from the end is including far, far more than a collection of maps, layouts, etc. ArcInfo maybe it is ended far more powerful, full of analyses capabilities, etc. But it was started on exclusive Unix machines. At ESRI they recovered slowly, migrating late, during the end of '90 to Windows machines. But as you said, we have only the core. Nothing to go, lets say, beneath the the surface. Of earth, water..... @batiporky Low technical users, loosing market ? I know some attempt of ESRI to enter on specialized markets...... and..... So: Exploration, mining: MapInfo/Discover (they are all now, ENCOM-Discover-MapInfo at the same company), Surpac, Vulcan, MicroMine Oil (exploration-production): Petrel, Kingdom Geophysics: Geosoft, Surfer Engineering: Underground water, foundations, etc Just count the possible business figures and try to find the ArcGIS or QGIS corespondent modules. Also, you will discover that they are a lot of highly specialized "low level" experts working in multi trillions industries....... Successful, with high tech results..... and without ArcGIS or QGIS. As I wrote before, beware to what you are targeting, to the appropriate software.... and to the GIS definition
  9. I can tell that MI+Discovery is an essential tool in the exploration and mining industry. Example: I can generate in less than a hour a grid for soil geochemistry and in the second hour to load in the GPS units the coordinates and send people to work. No such module in Arc. And they are a lot of such specialized modules in MI/Discover It is not about the core MI vs Qgis,it is about the final products. Same in geophysics, you will never find Qgis or Arc, you will find products processed in Geosoft..... Same in the oil industry. Other families, not Qgis or Arc So, see what you are targeting......
  10. I converted one time a grid in an ers format and the altitudes were exploded. In which step do you have these inflated elevations ?
  11. Probably is expensive: http://www.photosat.ca/mapping-services/30cm-accuracy-topography-mining.php?&utm_source=infomine-mining-com&utm_medium=web-ad&utm_campaign=mining-com-world-map
  12. Forget. A lot of Garmins are using also a barometer sensor. The 72 I think, it has a menu for skydiving...... But on a tablet is different of course
  13. Using a GPS, a Garmin 62sc on a boat near the shore: the error was less than 6 m. Error in theory, because they are other factors also: tide, the error of GPS system itself...... Place: Africa, 2 degrees south from equator
  14. You can try ecw compression format. It was real increasing the speed. Some simple thinks, digitizing large scanned maps. But the speed of redrawing was real fast after compression. Your software must support the ecw format Regards
  15. I think W32 is a dead end...Only 3.something gb memory used by the system, So, only an office Pc or something. The most interesting for me is the multi core capacity
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