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.
52
questions
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1answer
33 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 ...
1
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0answers
16 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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0answers
24 views
Convert grib to image using custom color scale?
I'm working on generating full color radar maps from a grib file. Example of the output I'm trying to create is here: https://boozedog.com/stuff/colorful.png
Here's the input grib I'm using: https://...
0
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1answer
192 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 ...
0
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0answers
45 views
SNAP Problem with Graph builder
I have a model in Snap that suppose to correct my sentinel 1 image. I have saved the model and load it again and now whenever I try to run the model I get red message on the bottom that the process ...
0
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0answers
43 views
Converting Level-2 NEXRAD to NetCDF
I need to convert Level-2 NEXRAD files (from https://mesonet-nexrad.agron.iastate.edu/level2/raw/) to NetCDF.
I am currently on a Linux system.
Has anyone had any success doing this?
5
votes
1answer
81 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 ...
0
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1answer
41 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
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1answer
186 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 ...
2
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1answer
119 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
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1answer
110 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
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1answer
248 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
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1answer
92 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 ...
0
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1answer
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
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0answers
27 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 ...
0
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2answers
177 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 ...
1
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2answers
628 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 ...
1
vote
1answer
94 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
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1answer
1k 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. ...
1
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0answers
96 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 ...
1
vote
1answer
295 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
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0answers
185 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 ...
2
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0answers
166 views
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 ...
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2answers
48 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
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1answer
624 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 ...
2
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1answer
2k views
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 ...
4
votes
1answer
459 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
2answers
560 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
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1answer
132 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
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0answers
320 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) ) ...
1
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1answer
1k views
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 ...
7
votes
1answer
6k views
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 ...
2
votes
1answer
95 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 ...
4
votes
1answer
522 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
1answer
5k 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
1answer
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 ...
5
votes
1answer
510 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 ...
3
votes
1answer
828 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 ...
1
vote
1answer
225 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 ...
1
vote
1answer
2k views
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
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0answers
239 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
1answer
176 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
1answer
468 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 ...
0
votes
1answer
2k views
Ground Penetrating Radar (GPR) to ESRI raster format
can anyone recommend a software package to convert ground penetrating radar data (in .dzt format) into an ESRI raster format? - Preferably free software.
I have come across ZondST2D, but as far as I ...
11
votes
5answers
28k 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?
3
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1answer
452 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 ...
1
vote
3answers
3k 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 ...
2
votes
1answer
2k views
Python package for processing GRIB data in windows
I would like to know what python packages can be used to process GRIB (Gridded Binary) data on a Windows system. I know there is something called pygrib, but to use that I have to use cygwin windows ...
1
vote
1answer
201 views
Finding Normal to a given point in ECEF coordinates
I have a point of reference called Ground Reference Point (GRP) given in Earth Centred Earth Fixed (ECEF) coordinates as given below:
(1.4892e+6, 6.1102e+6, 1.0637e+6) (all distances in meters)
I ...
2
votes
1answer
235 views
Applications and methods for TerraSAR X
People who already used or are familiar with TerraSAR X, can you point out:
Main applications and methods
Open source software tools
