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38 votes
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Panchromatic Image association with high spatial resolution

Panchromatic images are created when the imaging sensor is sensitive to a wide range of wavelengths of light, typically spanning a large part of the visible part of the spectrum. Here is the thing, ...
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  • 10.8k
29 votes

Scale 16 bit to 8 bit within range using GDAL

If you don' want the values above 255 to be cut, you need to scale them down. For that purpose gdal_translate provides the option -scale: From the Manual: -scale [src_min src_max [dst_min dst_max]]...
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  • 6,089
17 votes

Redefining nodata value into zero in QGIS

In QGIS, you can use Raster Calculator with the following calculation: ("your_raster" != -32768) * "your_raster" With this calculation, if the cell value is -32768 you will get a 0 in that cell and ...
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  • 3,500
16 votes

Redefining nodata value into zero in QGIS

The simplest one-step and, IMO, most consistently reliable solution to reclassifying NoData to zero is to use the Reclassify Grid Values tool (SAGA) in the processing toolbox. After selecting the ...
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16 votes

Spatial resolution of Google Earth Imagery

The resolution of imagery in Google Earth varies depending on the source of the data. When you zoom out, you will see the nice, pretty global coverage produced from a mosaic of many Landsat scenes, ...
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14 votes
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completing satellite imagery tiles when data coverage is less than 100%

For images of the same location but different dates, I would rather talk about compositing than mosaicing (which combines images from different extents into a larger image). You will find a lot of ...
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  • 48.6k
11 votes

Identifying image location?

IMAGE REVERSE SEARCH WITH GOOGLE IMAGES Doing a reverse search using images.google.com I found this link from wikimedia commons: https://commons.wikimedia.org/wiki/File:M%C3%...
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11 votes
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Programmatically retrieving Landsat 8 Satellite Images?

I saw a blog post from developmentseed for their command line utility landsat-util. Power tools for Satellite Imagery The landsat-util can be forked from github and compiled from source unless your ...
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10 votes
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Flattening multi-band raster to single-band raster in ArcMap?

I found this good discussion at http://www.cartotalk.com/index.php?showtopic=7109 and thought it would be useful to add to GIS.stackexchange for posterity. in ArcMap 10.2, choose > Windows > Image ...
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  • 20.5k
9 votes

Where can i download a good World image in GeoTIFF?

I was able to georeference an xglobe image using gdal_translate gdal_translate -a_srs WGS84 -a_ullr -180 +90 +180 -90 xglobe-2400.jpg xglobe-2400.tiff
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  • 191
9 votes

Spatial resolution of Google Earth Imagery

Maybe is to late to answer the specific question, but I hope that will help someone else: To identify a platform the historical imagery of Google Earth (GE): Turn ON Layers -> More -> SPOT Image OR ...
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  • 3,226
8 votes

Redefining nodata value into zero in QGIS

Having the same problem, in the end I used Python directly -- you may have to adjust numpy.where for your specific purpose. In the case below, the pixel values are kept as they are if they are >= 0, ...
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  • 653
8 votes

Mosaicking rasters in GRASS GIS

You can use r.patch for that (see help file) You probably want to set the region first to encompass all raster layers, after which you can use r.patch to 'mosaic' the layers. The following example is ...
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  • 1,673
8 votes
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Is it possible to determine Collection Date of ESRI World Imagery Basemap

You can do this with the Identify tool, just use it to click the World Imagery layer and it will tell you a few things about the imagery, including the date it was collected:
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  • 12k
8 votes

comparison of Historical aerial photographs to today's satellite images

Your biggest issue will be that aerial photographs from the 50s may well be in black and white and this doesn't provide good basis for standard classification, such as the tutorial linked by @...
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8 votes
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Is there an online catalog for declassified Soviet Union Spy Satellite images (Zenit-4, Resurs-F1, Okean)?

As others have shown interest for this question I'll answer it using the information I've been able to gather so far: There might be more than one archive or old Soviet Union imagery. As there were ...
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8 votes
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How to visualize multiband imagery using rasterio?

The Rasterio Plotting documentation describes how to visualize multiband imagery. For example, using 4-band NAIP imagery: import rasterio from rasterio.plot import show src = rasterio.open("path/to/...
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  • 50.2k
8 votes
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Should I always choose Sentinel-2 atmospheric-corrected imagery?

Atmospheric correction is particularly usefull if you need consistency between dates and/or adjacent tiles. Some studies showed that the use of atmospherically corrected images improve the subsequent ...
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  • 48.6k
7 votes
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What lens and camera settings are recomended for UAV (drone) aerial imagery capture?

All of the specific answers I can come up with would have likely already occurred to you as a photographer. A low distortion lens with a shorter focal length (based on your prospective altitude). High ...
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  • 15.5k
7 votes
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Download MODIS data for Mexico

you can find the H and V index in all MODIS product file name. These indices refer to the grid below (from the MODIS Website). For instance you have H8V6 (MOD17A3.A2000001.h08v06.055.2011276103801.hdf)...
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7 votes
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How to know which satellite took the image?

According to https://www.digitalglobe.com/sites/default/files/ISD_External.pdf you should have a field called satellite with a mnemonic like: “QB02”, “WV01”, “WV02”, “WV03”, “GE01”, “Aerial” Which ...
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  • 11.8k
7 votes
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How to split multiband image into image tiles using Rasterio?

Below is a simple example (rasterio 1.0.0 or later, won't work in 0.3.6). There might be better/simpler ways (and there is an easier way if your raster is internally tiled and the tile block sizes ...
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  • 51.8k
7 votes
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Using rasterio to crop image using pixel coordinates instead of geographic coordinates

You can use a window -rasterio.windows.Window to read by pixel offsets. The georeferencing can be easily calculated from the window using the source dataset window_transform method. import random ...
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7 votes
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Noisy lines in all scenes for Landsat 7?

You should read about the Landsat 7 ETM+ SLC-off data This refers to all Landsat 7 images collected after May 31, 2003, when the Scan Line Corrector (SLC) failed. These products have data gaps, but ...
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6 votes
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Colour matching satellite imagery from different time periods

The effects you are seeing are atmospheric effects due to differences in atmospheric aerosols, sun angle, and Rayleigh scattering. Since you have two scenes of the same location, though at different ...
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6 votes
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Satellites to retrieve UV bands

The US Naval Research Laboratory has developed the "Special Sensor Ultraviolet Spectrographic Imager" (SSUSI). Versions of it have been aboard DMSP satellites since 2003, improving in accuracy. It ...
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6 votes
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Making Leaflet image overlay draggable?

A simple workaround is to bind the imageOverlay to a draggable Polygon (thanks to w8r for this idea, developer of Leaflet.Path.Drag) var poly1 = [ [40.71222, -74.22655], [40.77394, -74.22655]...
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  • 133
5 votes
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Clipping MrSID files in ArcGIS Desktop?

The short answer is you can't produce a clipped sid image in ArcGIS 10, the format is proprietary. But you should be able to produce a clipped jpeg 2000 (jp2) which is similar. A typical sid ...
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  • 1,310
5 votes
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Filling in missing values in raster using R

I am the author of the R package gapfill, which is a flexible tool to predict missing values in spatio-temporal remote sensing data sets. https://CRAN.R-project.org/package=gapfill It could be helpful ...
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  • 211
5 votes

Flattening multi-band raster to single-band raster in ArcMap?

Suggestion from Stephen Lead is sufficient for grayscaled rasters but not for coloured rasters (e.g. DOF). If you want to preserve the colours (conversion is quite good) then use Copy Raster tool and ...
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