Questions tagged [radar]

A method of detecting distant objects and determining their position, velocity, or other characteristics by analysis of very high frequency radio waves reflected from their surfaces.

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Difference between Ground Resolution and Ground Range Resolution and their relationships

I'm curious about what relationship does ground range resolution have with ground resolution. I was reading "Nano-Satellite Swarm for SAR Applications: Design and Robust Scheduling" when ...
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Computing RCS from Envisat WV data

I need to obtain sigma0 (backscatter) from WVI or WVS SAR ENVISAT data. However, I don`t found that value on metadata and I also did not found other values to compute by myself. For instance, on ...
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Convert radar parameters to polygon

I have the following list of parameters for a given radar: Latitude Longitude Coverage lateral Coverage horizontal Max Range Power Emitted I would like to convert these parameters to some type of ...
2 votes
0 answers
36 views

Diffraction figure in Sentinel 1

I observed what I inteprete as a diffraction figure in Sentinel 1 data, and I have no idea what this is. You can se it if you go to 50.27252991423117, 38.04210455975978, the date of 2022-01-06, and ...
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3 votes
1 answer
99 views

Removing pixels of a GeoTIFF based on a scalebar

I wonder if it is possible to remove the pixels from a GeoTIFF based on a threshold of an scale bar using GDAL. For example I would like to remove the data below approx 12dBZ on the picture attached, ...
3 votes
1 answer
2k views

Adding weather radar data to leaflet from website

I am looking to add a specific layer from this website (https://www.iweathernet.com/total-rainfall-map-24-hours-to-72-hours) to a leaflet map in R. I have tried the code below, but the data does not ...
0 votes
0 answers
363 views

OpenLayers 6.x: Incorrect Static Image Location On Map -- React NextJS

VvI have been searching across the interwebs to find an answer to my problem that was answered a decade ago for a much older version of OpenLayers. I am trying to overlay a NWS Radar mosaic on top of ...
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1 vote
1 answer
76 views

Understand radar scan data

I have an exercice consisted on: X is a binary with raw data from the Austrian radar services. Each radar station scans 16 vertical surfaces with a displacement of 1 km. The file contains the ...
2 votes
0 answers
31 views

Complex SAR values in Interferogram

By what I understand, a "standard" slc from a SAR has complex values for each pixel. Here the phasor consists of the magnitude and the relative phase. What I don't understand is the complex nature of ...
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1 answer
1k views

How to solve "Collection query aborted after accumulating over 5000 elements"?

I am trying to sample image and to get scatter plot of its' two bands- NDVI and db from senttinel 1. For some reason, probably because of the size of the shapefile, I get the error: Error ...
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5 votes
1 answer
860 views

What do horizontal (H) and vertical (V) polarization mean for satellite radar?

I'm reading about synthetic aperture radar (SAR), and one of the basic concepts is that the transmitted and received signals can have "horizontal" (H) or "vertical" (V) polarization, but I can't find ...
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1 answer
69 views

What does "Ensemble average for a given window of pixels" mean?

Can someone please let me know what does "ensemble average for a given window of pixels" mean when calculating a coherency or covariance matrix? I have taken this sentence from a paper "Polarimetric ...
6 votes
1 answer
224 views

InSAR processing: why can't we just compute distances directly from time delays?

My question can be very basic, but even after studying quite a few tutorials on InSAR processing, I still do not understand one thing: if we know a wavelength, speed of light, a time delay it takes ...
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2 votes
1 answer
166 views

WhiteboxTools returns nan rasters when lee filtering large radarsat images

I am attempting to run the following code from WhiteboxTools: .\whitebox_tools.exe --run="LeeFilter" --input='imagery_HV_orig.tif' --output='imagery_HV_filtr.tif' --filterx=5 --filtery=5 --sigma=10.0 ...
2 votes
1 answer
242 views

How to calculate an incidence angle raster for a radarsat 2 scene using gdal / python?

I want to make a raster band that gives the incidence angle for each pixel in a radarsat-2 scene. I know this is possible using the information given in the product.xml file (below), but I'm not ...
2 votes
1 answer
486 views

Error in orthorectification of Radarsat-2 scenes with GDAL and RPC + DEM information

I am trying to use a DEM rational polynomial coefficient (RPC) information to orthorectify radarsat-2 images with GDAL 2.2.1. I have successfully done this with Orbview-3 images using the tutorial ...
0 votes
1 answer
165 views

Colorize radar imagery so it looks like optical imagery

Here is an imagery from a radar satellite Is it possible to colorize a radar image, so it looks like and enables the same kinds of analysis as for an image captured from an optical satellite (simple ...
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1 answer
5k views

How to make customized radar chart in R? [closed]

I am a beginner in R language and trying to make this picture. I tried radar. I tried using radarchart (radarchart(data)) but I do not know how to modify the picture. Here is my data: A B ...
0 votes
0 answers
33 views

Where do those cloud data overlay images come from

Certain time-based (rain) cloud data appears on different sites and apps. This gives the impression that the rain and cloud data is available (for free or licensable), and that multiple sites make use ...
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2 answers
271 views

Sun-synchronus orbit for SAR satellite

I have been following the news about the launch of the PAZ satellite (a SAR imaging sensor). The orbit will be sun-synchronous. I know this is important for optical sensors to make sure they have the ...
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1 vote
3 answers
2k views

Why side looking?

While reading about remote sensing systems I notice about the side looking approach. I got the idea, it means the sensor does not look directly down to Earth. But I still do not understand why. Here ...
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1 vote
1 answer
116 views

Incidence angle of geographic cordination

I am processing Sentinel 1 data with ENVI SARscape (can process also with gamma if it helps me) for earthquake inversion. Due to the fact that I want to use ascending and descending acquisition, I am ...
1 vote
1 answer
3k views

Terrain correction / Orthorectification with gdal

Since MODIS Imagery Orthorectification (Open Source) had no answer, I will try to get one here with a similar problem: I got some raster datasets with GCPs in lat/lon, but without height information. ...
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1 vote
0 answers
116 views

Weather radar imagery

Are there any services besides the NOAA that offer weather radar imagery for free? Some of the issues our users have with the images from nowcoast/radar_meteo_imagery_nexrad_time are the colors and ...
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1 vote
1 answer
338 views

Low Recall for Radar Image Flood Classification

I am following the example here to learn how to classify flood images. I am using a single band of the Sentinel-1 radar imagery. I am able to build and train my model without trouble. The problem is ...
2 votes
0 answers
194 views

Radar incidence angle of different images [closed]

I am beginning in radar traitement, I want to know if working with radar image with differents incidence angle is not correct for result, Could the radar image have the same incidence angle for ...
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Meaning of Spatial resolution (m) = 2 rng?

I'm reading a catalog about SAR sensors. On page 17, it is said that: I've read the PolSAR data format for UAVSAR before, But not the other documentations related to InSAR, because I didn't ...
0 votes
2 answers
52 views

Source of radar imagery for coastal areas [closed]

For my final year research project I need radar images of coastal areas. And can anyone help me to find links where I can download such data free for research purposes?
2 votes
1 answer
1k views

Why are there holes in these radar blobs?

I was recently looking at a live weather radar online and I noticed several "holes" in the radar blobs usually near the center of the blob. I also noticed that in a few cases that the holes stayed in ...
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2 votes
1 answer
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Calibration error for Sentinel 1 image in SNAP toolbox

I am working with a Sentinel 1 SLC IW image (VV+VH) and trying to calibrate the data in the SNAP toolbox. However, it keeps returning the error "cannot construct data buffer" Does anyone have any ...
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4 votes
1 answer
556 views

Is there a way to use the GDAL C++ API to find areas of overlap between two SAR images?

I have a bunch of SAR images (about 1 GB each) on which i need to do some image processing. Each image is georeferenced and there is significant overlap between each pair of images in the set ie. one ...
1 vote
2 answers
651 views

How to extract coherence and covariance matrices of TerraSAR-X data?

I have obtained quad-polarized level 1b TerraSAR-X data from DLR. When I tried to read the data using PolSARpro, I understood that it is only capable of reading SSC format But my data is in MGD (...
-1 votes
1 answer
142 views

About PolSDP software for SAR processing [closed]

Can anybody help me to find PolSDP software or provide a link from where I can download.
3 votes
0 answers
340 views

Import GPS SINEX (for velocity analysis) into Sarscape or processing with others software

I try to import GPS snx. into Sarscape 5.2 (use GPS Import tool) and getting error 115) ) gps_type : [sinex] 116) ) generate_kml : [OK] 117) ) generate_shape : [OK] 118) ) ...
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1 answer
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How to open SMAP's Surface Moisture data files

I downloaded surface moisture data from Nasa's Soil Moisture Active Passive (SMAP) sensor website (https://nsidc.org/data/smap/smap-data.html). For each processing level (1-4), three types of files ...
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8 votes
1 answer
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SAR - Using the Intensity or the Amplitude for the classification

In a Sentinel-1 Level 1 Ground Range Detected SAR data product, Intensity = Amplitude * Amplitude. Should the intensity image or the amplitude image be used for radiometric calibration when using ...
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2 votes
1 answer
101 views

Rigorous geometrical models for InSAR imagery?

I'm looking for rigorous geometrical models for InSAR imagery. I'm familiar with the rigorous models for SAR images, but I don't know the model for InSAR. I searched through the internet, but I didn't ...
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4 votes
1 answer
853 views

what does it mean to store cross products in SAR product data file?

I'm reading the UAVSAR data format For definition of two types of file we have: MLC files (.mlc): calibrated multi-looked cross products, floating point format, three files8 bytes per pixel, three ...
6 votes
1 answer
8k views

What is multilooking?

Today I found a video on youtube for multilooking the data with NEST (Next ESA SAR Toolbox) and it seems that it produces square pixel out of rectangular SAR pixels. Does it operate as simply as ...
2 votes
1 answer
2k views

Why is azimuth resolution worse than range resolution in Sentinel1 (SAR) [duplicate]

Why is the azimuth resolution in Sentinel (SAR sensor) worse than the range resolution? The table in this link gives the resolution for SLC products aquired in the different aquisition modes. In ...
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5 votes
1 answer
652 views

Why does the peak of a mountain appear bright on Radar images?

Why does the top of a mountain appear bright on a SAR (radar) image. I know that the peak of a mountain is subject to a layover effect, thus appearing closer on the radar image than the bottom part of ...
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3 votes
1 answer
1k views

Reading Synthetic Aperture Radar raster images using python

Is it possible to read and modify Synthetic Aperture Radar raster images using python? gdal is not able to understand their Type which is Binary (application/octet-stream). One can find sample radar ...
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1 vote
1 answer
244 views

Understanding InSAR interferometry?

I understand that the result of InSAR interferometry yields a LoS deformation and if deformation in the vertical or horizontal is to be computed, it should require additional gps observations at the ...
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1 answer
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Extract Differential Interferometry from SENTINEL-1 image

I downloaded some SLC images from scihub.esa.int . And I want to extract Differencial Interferometry from them by using SNAP-ESA software. How can I do it ?
0 votes
0 answers
246 views

How to visualize a C-band SAR sensor measurement

Files: \measurement\s1a-iw2-slc-vv-20141205t171642-20141205t171705-003587-0043c5-002.tiff Size is 24435, 13472 Coordinate System is `' Metadata: AREA_OR_POINT=Area TIFFTAG_DATETIME=2014:12:05 21:...
2 votes
1 answer
208 views

Geo referencing RADARSAT-1 image

I have lots of RADARSAT-1 file in GeoTiff format along with meta data where corner coordinates are available. Corner coordinates are for image portion(except the black portion). But, radar image has ...
3 votes
1 answer
603 views

I can't get my OpenLayers radar overlay to display correctly

I've tried to overlay a radar image on my map so that I can show the current radar for the United states. However, whenever I load the map, I can't seem to get the projection to look correct. Here's ...
13 votes
5 answers
31k views

Free radar (SAR) satellite data [closed]

I'm looking for free (non-commercial use) sources of radar (SAR) satellite imagery. Does anyone know of sources?
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3 votes
1 answer
486 views

Creating ALOS PALSAR 1.0 level JAXA Orthorectified K & C Mosaic interferometry

JAXA is providing free access to PALSAR 50m Orthorectified K & C Mosaic. The files are not in the typical PALSAR format. I'm looking for apps that can read and export this data. Is it possible ...
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1 vote
3 answers
4k views

Lowrance sl2 format... is it GIS data and/or can it be made into GIS data

I have been asked to investigate if Lowrance SL2 (side-scan sonar) format can be put into maps for reports. As I understand it the SL2 format comprises 3 "bands" left-down-right and is more of a ...