Geographic Information Systems

Questions tagged [imagery]

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Imagery refers to raster based datasets acquired from sensors on satellites or aircraft.

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11
votes
12answers
34k views

Redefining nodata value into zero in QGIS?

I have an image which i cliped with an AOI polygon. The contour area was set to pixel value = 0 and I have a nodata value of -32768. I want to redefine the nodata value into zero. I used to do this ...
3
votes
1answer
3k views

How to split multiband image into image tiles using Rasterio?

I have been using this answer on GIS SE to split 3-band (RGB) imagery into 256x256 3-band image tiles: import os, gdal in_path = '/path/to/indata/' input_filename = 'dtm_5.tif' out_path = '/path/to/...
27
votes
6answers
13k views

Programmatically retrieving Landsat 8 Satellite Images?

I have not been able to find out this myself, but is there a way to programmatically access Landsat 8 Satellite Images? I know that I can go to USGS EarthExplorer to search and browse through the ...
33
votes
7answers
4k views

Work flow for georeferencing imagery using open source tools?

Does anyone have a recommendation for a work flow for georeferencing high resolution aerial photography using open source tools? Comparison of user friendliness and robustness between Quantum GIS ...
10
votes
4answers
6k views

What causes shiny artifacts in Google Maps imagery?

Do you know what causes artifacts like this one? Source: http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=embelgasse+wien&aq=&sll=37.0625,-95.677068&sspn=60....
1
vote
2answers
3k views

TRMM data download

I need help in downloading 7 day composite TRMM data (Geo-Tiff) like this for past 10 yrs of the SE ASIA region. It is way too confusing where to obtain the data, I wanted to analyze the precipitation ...
13
votes
1answer
12k views

Scale 16 bit to 8 bit within range using GDAL

I am looking to scale a 16bit unsigned tiff image to an 8bit image using GDAL (OSGeo4W). However I want to constrain the pixel values so that they stay within the range of the 8bit imagery. What I ...
4
votes
2answers
11k views

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

I need to convert a multi-band PNG image into a single-band raster, for analysis and visualisation. How can I do this in ArcGIS Desktop 10.2?
5
votes
2answers
3k views

Is it possible to determine Collection Date of ESRI World Imagery Basemap

It seems like it was possible to do this with Google Imagery if I recall but is there any way to determine the date of collection of Esri's World Imagery basemap (or other basemaps) at a given ...
20
votes
1answer
35k views

Panchromatic Image association with high spatial resolution

How and Why is a Panchromatic Satellite Image associated with high spatial resolution? I googled and found that it is a single band image, but then why is it called pan-chromatic(All Colors). Does it ...
18
votes
7answers
6k views

Seeking Satellite Imagery Providers? [closed]

I'm building a web application - my requirements are: Must have global satellite imagery. Must have easy to use API's that are capable of geoJSON data imports, mouse and keyboard gestures, etc. To ...
14
votes
2answers
72k views

Identifying image location?

I have a satellite image of only one part of some city with a lot of vegetation. I need to find out where is that image taken. Is there any way to find out where it is taken on Google Maps, Google ...
18
votes
3answers
2k views

Alternative vegetation indices

I have been using NDVIs with limited success to identify trees in the central Great Plains region of the USA. The problem I have been encountering is that reflectance from farm fields/pastures have ...
8
votes
3answers
4k views

Poor image quality of raster pyramid files in ArcGIS Desktop (no anti-aliasing)?

There are several GeoTIFF files (size ~7000x7000 px) which I try to open in ArcGIS Desktop 10.0. I have already created raster pyramids for them (.ovr files) using geoprocessing tool but their quality ...
7
votes
5answers
2k views

Georeferencing aerial photos when only centroid is known using ArcGIS for Desktop or ERDAS Imagine?

I have heaps of aerial photos that need to be georeferenced. I have access to ArcMap and ERDAS. All I am given is an excel sheet with the centroid coordinates of each image. Each photo covers ...
7
votes
1answer
270 views

Determining Bounding Points of UAV Images

I know the EXIF data from drones contains the GPS point central to the photo to provide photo location. What I'd like is to determine the lat/lon of the four corners of the image. I've done a pretty ...
6
votes
2answers
1k views

Extracting RGB values from aerial photo and assigning to LAS file with FME?

I need to extract the RGB Values from imagery and assign to a .las file in order to display 3d landscape with "real" colours. I have an unlicenced LAStools, FME 2017 and ArcGIS 10.3.1 at hand. I ...
4
votes
4answers
5k views

Where to download 4 band NAIP imagery?

I seem to recall USGS Earthexplorer providing current and historic 4 band NAIP imagery over the last few years. It appears that these data have been migrated to the National Map. However, the ...
4
votes
1answer
4k views

Clipping MrSID files in ArcGIS Desktop?

Does anyone have experience subsetting/clipping a large NAIP imagery file in MrSID format? Some of the NAIP files we have are by county and they have really large file sizes. The files are from the ...
3
votes
3answers
2k views

Which Software can derive building footprints from imagery?

I'm looking for a software solution that can process large areas of imagery to produce building footprints. For the area of interest, I can source either satellite stereo pairs or oblique imagery. I ...
3
votes
2answers
686 views

SPOT NDVI time series

I have 423 spot.vgt ndvi from first April 1998 till 31 Dec 2009. I want to know how to stack these NDVI to have one image for time series analysis? Or better to ask how is it possible to analyze a ...
2
votes
0answers
701 views

Google Satellite Imagery Offset in QGIS

I am using Google Satellite imagery as a base map to capture the vector data in QGIS 3.2.2 for past couple of months. Yesterday i noticed that the google imagery has offset issue in some locations ...
8
votes
1answer
6k views

What lens and camera settings are recomended for UAV (drone) aerial imagery capture? [closed]

I have been toying with the idea of purchasing/bowrrowing a UAV and attempting to capture my own aerial imagery. I have pretty good DSLR Canon gear and several lenses but I am wondering what lens, ...
6
votes
2answers
1k views

Using Custom Aerial Raster Imagery with OpenLayers 3 or 4

Currently, openlayers supports bing maps, however this is not an ideal option for a commercial application. What would be ideal is to have the ability to host and serve ariel imagery like NASA blue ...
5
votes
2answers
1k views

Extract certain area of contours/satellite images

I have 2 satellite images (jpeg2000 format) and 2 xyz-files from the same area. I am trying to extract certain region from the area including contour lines and the satellite image in order to import ...
4
votes
1answer
6k views

Calculating raster statistics for each band in QGIS?

i need to calculate raster statistics for RGBN (4 channels, multiband image) rasters in QGIS. In Arcgis if you use "calculate statistics" in ArcCatalog, statistics are calculated for every image ...
3
votes
1answer
2k views

Convert 3-band raster imagery to distinct vector zones in ArcGIS

So much like the title says I would like to convert a 3-band infrared image TIF file of vegetation into distinct vector feature zones using ArcGIS. I'm guessing the only way to do this is with ...
3
votes
1answer
2k views

How to list raster bands?

I am interested in looping through a directory and listing only the red bands (Band 1) from 4-band NAIP imagery. From there I would like to mosaic all of the band 1 layers into a new single band ...
3
votes
2answers
4k views

How to convert GeoTIFF to grayscale and add gaussian blur?

I have a giant GeoTIFF I'd like to convert to grayscale and add a gaussian blur to. As far as I know, GDAL can strip two of the three color bands and call it grayscale, which might work, but is there ...
2
votes
1answer
103 views

NASA world view (EOSDIS) coverage delay per day - scanning footprint issue?

I noticed that in NASA world view web site it's take some time to get per day world wide coverage. I made some calculations: The source is Aqua & Terra satellites Both have orbital period ...
2
votes
3answers
2k views

Is there a source for leaf-off aerial imagery?

I am looking for leaf-off imagery for Oklahoma, Kansas and Texas. 1m leaf-off imagery would be ideal, although any substitute would be helpful. I need fairly high resolution imagery to distinguish ...
2
votes
0answers
2k views

Automated testing for GIS apps

There are several commercial and opensource tools for regression automation. While many of them could be employed to test GIS apps, they fall short, at times, dealing with the unique characteristics ...
2
votes
1answer
491 views

Writing custom Prepare Scripts for Open Data Cube?

How do I write custom prepare scripts for the Open Data Cube format ? The docs say the following: We expect that many new Data Cube instances will require custom prepare scripts to be written. It ...
1
vote
0answers
324 views

Load MrSID file in QGIS 2.2 on Ubuntu 13.10 [duplicate]

Is there a way to do this? I have tried a number of the write ups on this, and it appears that libgdal-mrsid-src no longer exists. Is there any other workaround? USDA NAIP imagery is sent as MrSID.
1
vote
2answers
4k views

Making Leaflet image overlay draggable? [closed]

I simply want to make a georeferenced imageOverlay draggable in leaflet. I found several unanswered posts (e.g. here and here). Since it is easy to make markers draggable, someone tried to adapt the ...
1
vote
1answer
2k views

How to determine the bands from an aerial image?

I received a set of aerial images taken with a Canon camera, I don´t know which kind of lens it has, or if it has been modified. After performing split image algorithm in Qgis, I get four new files: ...
0
votes
1answer
383 views

KMZ with orthomosaic shows white squares with red Xs when zooming in Google Earth Pro?

Every time in the morning when I first open my Google Earth Pro, Why does my kmz that has an orthomosaic show white squares with red X's when you zoom in? Here is a screenshot: I tried to clear out ...
6
votes
2answers
801 views

Wavelet vs Discrete compression for imagery

What is the main reasons to choose wavelet (jp2, sid, ecw) instead of discrete (JPEG) compression methods for raster data? Lets limit this question to aerial imagery and lossy compression. Why ...
5
votes
2answers
7k views

How to visualize multiband imagery using rasterio?

How do I plot a satellite image using rasterio? I'm able to plot the individual bands but not the entire image. Is there a way to combine the separate R, G, B numpy arrays to create a standard RGB ...
5
votes
2answers
595 views

Pictometry Accuracy and/or Alternative

I'm looking for some insights into the accuracy (x,y,z) of oblique imagery from Pictometry in terms of providing accurate measurements for property evaluation. Is the high cost of this product ...
3
votes
1answer
3k views

How do I convince gdal2tiles to output pngs with transparency?

I have a tiff that was created with Pix4dmapper. This tiff has coordinates embedded (as seen in the logs below) (I think that makes it a geotiff?) as well as a tfw file associated with it. Opening ...
3
votes
2answers
2k views

Where can I find non-rectified stereo satellite imagery?

I'm looking for free (as in beer and as in commercial-use-friendly freedom) sources of stereo satellite imagery. I assume that such imagery should not be rectified since that would remove the benefits ...
3
votes
2answers
563 views

Geographically Semi-accurately georeferencing image with limited information [closed]

It is possible to semi-accurately georeference an image given only the following information? I'd like to do this programmatically. Center point of terrain, Lat/Lng (WGS84) Pitch of camera FOV ...
2
votes
0answers
352 views

Add basemap copyright in QGIS?

I am using the QuickMapServices plugin for basemap imagery and was wondering if I can add a QGIS legend that includes default copyright information? I know this can be done in ArcMap...!
2
votes
1answer
1k views

Adding Esri imagery to QGIS using “services.argisonline.com”

I'm trying to add this particular imagery in QGIS: http://services.arcgisonline.com/arcgis/rest/services/World_Imagery/MapServer/3 But when i write the phyton srcipt i get the message that the URL ...
2
votes
1answer
182 views

Determining Longitude and Latitude of each corner of image

With this information below, including image size, longitude/latitude (of upper left I assume, maybe center), Resolution, and altitude - can I derive the Long/Lat of each corner of the image? "size":[...
1
vote
2answers
2k views

Using ESRI World Imagery (for Export)?

I would like to download some of the ESRI World Imagery using this however when I try to add the layer to an online map I get "The layer, World Imagery (for Export), cannot be added to the map". I've ...
1
vote
1answer
423 views

Importing World Map image changes color in ArcMap?

I am having a hard time finding a world relief map with "lighter" ocean colors that will actually display as such in Arc. This is the image I download from the web but this is how it displays in ...
1
vote
1answer
213 views

Avoiding Esri basemap (Bing imagery) to update?

In my ongoing research, I intend to map transformations. That implies that, based on the ESRI basemap from Bing imagery, I draw certain features (in different layers) as they are today and as they are ...
1
vote
1answer
266 views

Increase contrast of merged Planet Labs scenes

I've download a few PlanetScope scenes from Celaya, MX. Taken alone they have a good contrast. Then I've merged them with gdalbuildvrt, which lowered the contrast: Link I've thought, that I could ...

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