Questions tagged [remote-sensing]

Collecting and interpreting information about the environment and the surface of the earth from a distance, primarily by sensing radiation that is naturally emitted or reflected by the earth's surface or from the atmosphere, or by sensing signals transmitted from a device and reflected back to it.

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2
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1answer
384 views

Calculation of fractional cover for each vegetation class at 30-m resolution matching MODIS swath in R

Currently I have a Landsat land cover map with 30-m resolution and I want to calculate the fractional cover for each vegetation class (forests, grasslands and croplands etc.) matching MODIS swath and ...
2
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1answer
928 views

Download AVHRR 1 km SST data

How to download NOAA AVHRR 1 km resolution sea surface temperature data? I need a SST 1 km image of the coast of Netherlands with at least 20 % valid pixels. After searching and searching I find the ...
2
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0answers
26 views

Register an image using mutual information

I want a procedure for registering two images based on their mutual information. I took a pair of georeferenced radar images of the same location, edited the metadata of one so its position was off by ...
4
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1answer
208 views

Does RapidEye level 3A imagery need any kind of preprocessing before applying classification?

I just got some rapideye images and I would like to know if there is need of any preprocessing before applying classification to it? I know that there isn't any automated way of, for example, applying ...
1
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0answers
149 views

Topographic correction in QGIS SAGA error: Input layers do not have the same grid extent

I have sentinel-2 layer images and one TIN image. I resampled the TIN to same spatial resolution in Layer 4 (10m). Both images are in the same reference system. But when I try to perform topographic ...
2
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1answer
126 views

Surface reflectance product - do I always need it?

There is a neat Surface Reflectance product of Landsat imagery. I know the difference between SR and raw products: SR presents calculated values, that are supposed to represent state of the Earth ...
10
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3answers
3k views

Raw Sentinel 2 jp2 to RGB geotiff

I'm looking for a way to merge Sentinel 2 jp2 band files(B02, B03, B04) and fix RGB colors. All should be done with bash or python script. For my example I work on these images. Ideally the solution ...
1
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0answers
101 views

Transect profile plot matlab

I have 3D matrix file where XYZ are lon,lat and height. I plot these XYZ value using scatter3. Now I want to plot profile of height (along a line in km) of the data where xaxis:distance along line in ...
4
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1answer
609 views

Landsat / MODIS spatio-temporal fusion: STARFM and software implementations

My main goal is to create Landsat/MODIS image pairs, perform an spatial-temporal fusion which leads to synthetic composites on dates between Landsat acquisition dates. This brought me to the paper ...
2
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2answers
390 views

Missing Landsat TM scenes for the year 2005?

I have searched Landsat TM images (path/row 149/37) for the year 2005 (1st Jan to 31 December 2005) on Glovis, Earth Explorer, Landsat Look and University of Maryland archive to work with. However, no ...
2
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0answers
263 views

Using python spectral package? [closed]

I found this tutorial about spectral using python and I will test kmeans classification using Landsat image. I don't understand some things about this tutorial. First thing I can't understand is about ...
1
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0answers
58 views

Using result raster of Semi-automatic classification to obtain spatial statistics?

I finished classification (use SACP in QGIS), and got a classificated raster. Now I want to obtain characteristics such as sum area of class, areas of different polygons separately, etc. I tried use ...
2
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1answer
2k views

Filter Image Collection by Multiple WRS Path/Rows in Google Earth Engine?

How can I filter an image collection in Google Earth Engine by multiple WRS paths/rows? This is an example of a filter using one path.row: var sr2011 = ee.ImageCollection('LANDSAT/LT5_SR') ....
1
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0answers
50 views

Loading MOPITT data into QGIS?

I have a problem importing Terra MOPITT data into QGIS (2.18) correctly. The data is in hdf5(HDFEOS) format. QGIS/GDAL imports the data, but the image is rotated by 90° and shifted. QGIS error: CRS ...
0
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2answers
527 views

Get ASTER full bands file

I am having some problems on downloading ASTER data. When I download a Landsat-8 scene, it cames with the full bands on it (14 band files), an metadata file and a quality file. I need to download ...
1
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1answer
54 views

Satellite image of agriculture land cover for some country [closed]

I am looking for a free satellite image of agriculture land cover for North Korea. Can someone guide me to any free resource. Is it available on earth Explorer, if yes, which image should I download....
1
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1answer
270 views

Landsat level-2 NDVI valid range with saturation

I have Landsat level-2 NDVI tiles I am using in ArcMap 10.4.1.; however, the level-2 NDVI data in ArcMap ranges from -5,189 to +20,000. The spectral image product guide (which I've linked) says that ...
2
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0answers
49 views

Is there an arXiv-like electronic archive used by the remote sensing community?

Mathematicians, physicists, and (theoretical) computer scientists use arXiv extensively to share their preprints. Indeed, one could say that it's the established way to share one's research. Is there ...
4
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5answers
2k views

Simple way to collect the Sentinel data of a given ROI?

If you wanted to collect all Sentinel satellite data for a given region of interest (ROI), say, for a given day or time frame - is there any simple way to do it? That means: Without having to download ...
-1
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1answer
442 views

Photomosaic non-georefferenced images using open-source software

I have a directory of images that were captured by drone. The images have GPS info in the EXIF tags but are not georefferenced and do not have world files. I would like to merge these photos into a ...
2
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0answers
157 views

ENVI shows colors of different RGB code the same in a bitmap image wrongly?

As you see in this picture which I've captured in MATLAB, there are two colors. Red with the RGB code (255,0,0) Brown with the RGB code (138,139,1) I've tried to show the same picture in ENVI, ...
16
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2answers
819 views

completing satellite imagery tiles when data coverage is less than 100%

I want to join several images (>=2) into one "best" image. Best is defined on low cloud cover and high data coverage. An example using free Sentinel satelite data follows. See http://sentinel-s2-...
1
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0answers
489 views

Automatically exporting time series of multiple polygons to .csv [duplicate]

I want to export data to a .csv file without having to display the chart. Similar to what is done here. I want to skip the chart-display part because I'm working with long times series and if I try ...
3
votes
1answer
504 views

How to sieve a raster with 1 and NaN values?

As a next step to my previous question "How to calculate where raster a is not equal to raster b?", I now want to sieve (using QGIS -> Raster -> Analysis -> Sieve, or gdal_sieve in the shell) a raster ...
0
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1answer
426 views

How to mosaic multiple modis tiles of several dates using mrt tool?

How to mosaic multiple tiles of Modis MOD13Q1 in loop. I have about 395 files of each tile from a total of four tiles. I am using linux operating system and therefore use shell script. I need to ...
1
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1answer
2k views

Processing LANDSAT 8 data in R (using packages Raster, RSToolbox, etc.) in order to calculate NDVI and land cover classification? [closed]

I am analyzing several LANDSAT scenes from the LANDSAT 8 OLI mission (18 in total, all from Jan 2017 - cloud cover < 20%). I now want to calculate the NDVI and do some land cover classification on ...
0
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0answers
49 views

Change DEM to match spatial extent and pixel size of unprojected RADARSAT image (ENVI)

I have a raw "Path Image" RADARSAT image as a CEOS file, which is by default not georeferenced and in units of Digital Numbers (DN). I'm trying to convert it to a projected geotiff in units of ...
1
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0answers
60 views

Is there any specific index for identifiying settlements in remote areas through Landsat or Sentinel images? [closed]

I am trying to identify (especially) small settlements in Nigeria that have no electrification. So is there any index that could help me detect households from Landsat or Sentinel images?
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0answers
105 views

Can NIR minus Red be used instead of NDVI with Drone Imagery

I have some CIR imagery collected by a vendor using a Cannon Powershot S110 NIR, from an eBee fixed wing platform, about 400 ft AGL. All images were stitched together by the vendor in Pix4D. I want to ...
2
votes
1answer
107 views

What possible explanations are there for a dramatic change in vegetation appearance in Sentinel 2 data?

I'm looking at land cover in an area of South East Asia. I pulled down Sentinel 2 imagery for Feb 2017, and used the QGIS SCP plugin to complete the land cover analysis, as per this tutorial: https://...
2
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1answer
297 views

Landsat Collection 1 Level-1 or Landsat Collection 1 Higher Level?

I want to use NDWI and NDVI index in my study for a time-series analysis using all products available (Landsat 5,7 and 8). Can I use the product Landsat Collection 1 Level 1 for my analysis or ...
1
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1answer
703 views

Principal Component Analysis in ENVI

I have a hyperspectral image on which I have performed PCA and now intend on using the output PCA components as an input into a classification. This is the first time I have done PCA, am i correct ...
1
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2answers
73 views

Pan-Sharp hillshade?

I have an SRTM-derived hillshade (30x30m) and a Quickbird scene (0.6x0.6m). Is it possible to kind of pan-sharp the hillshade to have the detail but also have the topography?
1
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0answers
67 views

Endmember selection when applying SAM, SVM and MLC to PCA

I intend to apply the Spectral Angle Mapper (SAM), Maximum Likelihood (MLC) and Support Vector Machine (SVM) algorithms on a hyperspectral dataset in ENVI but I am slightly confused as to how to ...
2
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2answers
368 views

Sentinel-2B API download

I tried downloading Sentinel-2B imagery from https://scihub.copernicus.eu/s2b with python urrlib2 but get HTTPError: Unauthorized on urllib2.open(). The same procedure works for https://scihub....
7
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2answers
1k views

Extracting building footprints from Sentinel-2 imagery

My attempt to extract building footprints from Sentinel-2 images using machine learning algorithm trained on Sentinel-2 images produced a lot of false positives and there is no sign that the algorithm ...
9
votes
2answers
324 views

Identifying Joshua trees with LiDAR data?

I'm working on a LiDAR project to determine where Joshua trees are located within a specified study area. Due to the vegetation cover being so sparse, there are really on 2 canopy species there, which ...
11
votes
1answer
815 views

Gram-Schmidt pan-sharpening in QGIS?

I need to perform Gram-Schmidt pan-sharpening, I don't have access to ArcGIS or ENVI so have been using QGIS. Is there any plug-in or similar capability that is available to perform Gram-Schmidt pan-...
2
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1answer
86 views

Performing crop classification without training points (sampling)?

Just theoretical (and maybe very silly) question - Is it possible to do crop classification (supervised or unsupervised) from multi-spectral camera or SAR without direct nexus with training points or ...
1
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1answer
255 views

ENVI FLAASH Error

I try to run FLAASH on a Landsat 8 image. I radiometrically corrected the image using FLAASH output parameters using ENVI 5.4. It gives me the error message: ACC error: modrd5:reading archive file ...
1
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0answers
44 views

LiDAR Lines Having Erratic Patterns [closed]

I have processed a LiDAR data and produced LAS files for an area that was flown by my team. We have processed some areas and the outputs were pretty good. I observed that we are now getting erratic ...
3
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2answers
2k views

Do clouds reflect NIR/Red bands

When using Landsat 8 imagery to calculate NDVI, will the NIR and Red bands be affected by cloud cover? In other words, will clouds produce a wrong NDVI calculation?
0
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0answers
614 views

Calculate reflectance for UAV images

I have high resolution images captured by a drone using a , they are RBG and NIR images. My question is how can I calculate the reflectance for the images, the values are currently in digital numbers (...
1
vote
1answer
108 views

Cleaning up polygon generated from NDVI raster

So I have NDVI raster files for about 1000 acres of vineyards we manage. What I have done is created a model that takes the NDVi raster, reclassifies it to isolate out the areas of high vigor, then ...
0
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2answers
500 views

Stop WriteRaster in a for loop in R

I just picked up R this summer. I created a nested for loop so that nls() will be performed in 24 raster layers and a new file will be created to save the data. In this example, I have a raster ...
3
votes
2answers
72 views

Select relevant bands from multiband raster?

I try to extract woodland areas from a greyscale orthophoto. I used the "Haralick Texture Extraction" from the Orfeo Tool Box to calculate texture properties of the greyscale orthophoto. As output I ...
1
vote
1answer
429 views

sound / noise pollution data

I'm looking for a geo-database on noise or sound pollution, ideally covering the area of one full country or more, e.g. measuring noise in dB. I am not interested in under-water noise pollution! I am ...
1
vote
1answer
59 views

Checking Vegetation height accuracy in urban areas

I have digitized vegetation as polygons covering the canopy of trees in urban areas. Are there any suggestions to check the accuracy of height. I have been manually validating with visual checks, ...
2
votes
1answer
1k views

How to use Landsat surface reflectance pixel quality band?

I'm using TIMESAT for time-series analysis and Landsat 7-8 Collection 1 images. Within this process I would like to use Landsat pixel quality band for assigning reliability degrees to the pixels using ...
1
vote
1answer
263 views

Timesat image output to ArcGIS

I processed MODIS MOD13Q1 NDVI times series (from 2000 to 2015) in Timesat. I specifically extracted start of season data and for each year (growth season) I was able to produce an image showing the ...