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17

GPS was built with military uses in mind during the Cold War. In 1983, Korean Air flight 007 was shot down by Soviet interceptors over Kamchatka when it went off-course. All passengers and crew aboard the civilian flight, including a sitting US congressman, were killed. Amid the ensuing controversy, President Reagan announced that GPS would be made available ...


15

I agree with @vascobnunes opinion but if you want to define certain objects you have to use LANDSAT TM because more classification needs more bands as (R, G, B, NIR, MIR, TIR, FIR)... and my choice is that you should use LANDSAT TM (I gave same information in the following explanation) for vegetation. The important thing in this case is that you should look ...


13

I have used OpenCV in the past to train for object detection for geo. Orfeo Toolbox is a good open source choice as Vascobnunes pointed out. For a closed-source version, you can take a look at Feature Analyst (that also has an ArcGIS extension). At the end, it boils down to training a support vector machine. There are several libraries that you can use for ...


13

Unfortunately I can't view that video from Canada but based on the screen shot I believe something like that could be rendered in Pov-Ray. A while back I asked a question about how to generate a high resolution rendering of the globe and @scw suggested I try Pov-Ray. Using this guide I was able to create custom globes with a combination of my own inputs ...


12

If you can, use GIS software, which is designed with this problem in mind: instead of reading the entire dataset into memory, it will only sample the image to create a display and no more. Something like QGIS should allow you to visualize the data, and provides ways of exporting the view, as one approach to creating a downscaled version. Another option is ...


10

If you only have SPOT 5 and Landsat TM to choose from, money is not a problem and for a small area of 30 000ha, I would agree that SPOT5 is the best choice, although Landsat would have some strong advantages: SPOT5: 2,5 m spatial resolution 3 spectral bands (Green, Red, Near Infra-red) about 2,64€ per sqkm for new acquisitions good revisit time biggest ...


9

There is a plugin in QGIS called Image Boundary. It is a great tool. Within this tool there is an option for "Valid Pixels" which will omit the black edges of a satellite image, for example.


8

Imagery is expensive to capture and produce, which effectively limits its production to commercial entities and governments. Most of the commercial satellites don't carry consistent global coverage and generate income by selling access to scenes, including their resale to the providers you listed. That leaves government options in the free category: perhaps ...


8

GPS is a public service made free to access so that the country can collectively improve its knowledge of the technology. As in the case of the internet, this presents an opportunity for the more industrious among us to diversify its application at a faster rate. And when someone succeeds in finding a new and useful purpose for GPS, money is circulated. In ...


8

Glovis is one of the best places to start compiling free satellite imagery. For a new user, LANDSAT imagery is a great place to start - you will be able to find data covering the 1970's to present day. There is also a wealth of information available for working with this data. For example, if you are using ArcGIS you can quickly learn how to develop a ...


7

Some things to consider: 1) Is the aerial imagery going to come stitched together already or are you going to have to manually stitch and post-process each image. You'll probably have to post process the satellite imagery. 2) When was the imagery acquired? For many features (e.g. rock outcrops) you're going to want leaf-off imagery. 3) Was the imagery ...


7

http://www.google.com/permissions/geoguidelines.html is pretty clear and simple


7

The first is "Create Vector". The bitmap [Raster] is translated to vector notation as soon as possible. That is, each single bit is converted into four directional vectors, joined as a square. The second is "Simplify Vector". The vector field is simplified by checking for duplicates and removing the vectors that are lying on top of each other (these would ...


7

I am afraid satisfying roof detection cannot be achieved with only one single satellite image. You should try to use other sources of information. The following article describes a method using a DEM + aerial image pairs + cadastral data: M. Durupt, F. Taillandier. Automatic Building Reconstruction from a Digital Elevation Model and Cadastral Data: An ...


7

There are published coefficients available for MSS, TM5 ETM+7, QuickBird and IKONOS but I do not believe that anybody has derived coefficients for Rapid Eye. Here is a paper that describes how the authors derived the coefficients for Quickbird (http://www.asprs.org/a/publications/proceedings/pecora16/Yarbrough_L.pdf).


6

One of the most simple ways to characterize vegetation from imagery is to utilize NDVI. In short, NDVI takes the difference from the spectral band with the highest EMR reflectance (nIR) and the spectral band with the lowest reflectance (red) and normalizes this value by dividing by the sum of the highest reflectance (nIR) band and the lowest reflectance ...


6

You can get Sentinel-1 data from scihub.esa. Requires only registration (And most likely, non-commercial use). As Sentinel-1 has just become operational the archive is not very extensive but should grow quite quickly. You can set request data-access propospal on Alaska Satellite Facility. Some data open access. For ALOS-PALSAR you must be a resident of the ...


5

have you tried the orfeo toolbox?


5

You are better off using a remote sensing application. Of course, you need to have the raster imagery on your computer. There are tons of methods that can help you determine woodland areas, such as: using Neural Networks, trained patches of imagery, supervised/unsupervised segmentation and classification. I'm not sure if this solves your problem, but it's a ...


5

Is is possible that LIDAR has been flown recently in the area? You can extract buildings this way... LIDAR would most likely be too expensive to fly yourself, probably at least 8-12k for an area that size. http://knol.google.com/k/aerial-extraction-of-roof-surfaces-for-solar-analysis# Found that article, may be of some help.


5

In QGIS, use the Clipper raster tool, under the Raster-> Extraction menu. See: How to clip a raster with vector boundaries? You may have issues trying to clip data in a plugin layer (e.g. Openlayers) because the Clipper function requires a input graphic file (raster) from disk. Your best bet is to get the satellite imagery directly from the source and ...


5

The following code will take an input raster, get it's extent, and insert that extent into a polygon featureclass: import arcpy r = arcpy.Raster(in_raster) point = arcpy.Point() array = arcpy.Array() corners = ["lowerLeft", "lowerRight", "upperRight", "upperLeft"] cursor = arcpy.InsertCursor(fc) feat = cursor.newRow() for corner in corners: ...


5

List of all website providing free Satellite images available here on this site http://www.indiaremotesensing.com/p/download-gis-data_6.html


5

Assuming you have the distance from the observer to the satellite--without which the problem has no definite solution--then this amounts to solving three subproblems, using the strategy of computing the satellite's geocentric Cartesian (x,y,z) coordinates. In the following, a is the semimajor axis (6,378,137.0 meters in WGS 84) and b is the semiminor axis ...


5

As someone who did feature capture from imagery for a while, I would caution you against expecting a pool at a spring. The majority of the ones I've encountered (both in capture and on the ground in person) don't have one. We often referred to ancillary sources to suggest/confirm a spring. Depending on your purposes, USGS quad sheets or hydrography datasets ...


5

Only managed to find a couple of sources for SAR images and data: You can download SAR images from here which are mostly focused on ecological sites such as forests: You can download SAR samples from here which contain fairly large datasets (note: the last 4 links at the bottom of the SAR section are dead) Hope this helps.


4

The OpenAerialMap project was abandoned, but has recently been restarted. It will be an amalgamation of free datasets from different areas of the planet, with global datasets for areas with nothing more detailed. The global datasets used are i-cubed, and the NASA imagery. The current list of datasources used by the projects can be found here. The source ...


4

Here's a page that discusses several models of GPS that are known to work in balloon applications: http://ukhas.org.uk/guides:gps_modules It looks like the COCOM limits are imposed differently by manufacturers - some use an altitude 'OR' speed limit check, the others use 'AND'. My next question would be just how much 3D accuracy you would get out of a GPS ...


4

These probably aren't exactly the droids you're looking for, but the ASTER DEM is constructed using stereographic correlation. Hirano et al describe the process for creating the DEM using stereo pairs. The only problem with ASTER is that its stereographic capabilities come from specific off-nadir tasked data collection. So unless you want to shell out big ...


4

You can buy high resolution satellite images from DigitalGlobe or GeoEye. You are not limited to these two map providers. There are too many options outside of these. You can also try Google Earth Pro for exporting images and with your license you can use Google Earth Pro images and data for marketing purposes as long as this data is not sold to any third ...



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