Questions tagged [sar]
The sar tag has no usage guidance.
23
questions
8
votes
1answer
183 views
Layers misaligned in QGIS
I have two National Imagery Transmission Format Standard (NITF) files loaded into QGIS 3.10 and they should be the same coordinate system but for some reason I cannot figure why they are not aligned.
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1
vote
1answer
33 views
Manipulating Sentinel-1 SAR Imagery to get Pixel Information
For S1 SAR imagery data, how would I go about accessing the data of individual pixels? I need to analyze pixel intensity based on their lat and lon coordinates. I know this information is viewable in ...
0
votes
0answers
11 views
How can I Generate Pauli pseudo-color image from polSAR T3 .bin file?
I'm confused about the process of generating Pauli pseudo-color images in the polSAR research field. I've tried to use polSARpro software and look up its source code for understanding this process but ...
1
vote
0answers
26 views
SAR calculating distance between 2 points
I am playing around with ESA's SNAP software and Sentinel-1 data and I was curios if it is possible to measure the ground distance between 2 points in a radar image. For example let's say that I am ...
4
votes
1answer
45 views
Sentinel-1a real azimuth resolution
I was exploring this satellite's payload characteristics on ESA's website and I saw that it's azimuth resolution varies a lot. For example azimuth resolution for IW mode is 22m (https://sentinel.esa....
0
votes
1answer
16 views
Using GDAL for reading calibration and annotation data set
I have a Sentinel-1 .SAFE data which provides a wealth of information through .tiff images and also .xml files containing annotation and calibration information.
Following the instructions in the ...
2
votes
0answers
26 views
Synthetic Aperture Radar data format
I'm trying to learn about the SAR image formation process. From reference such as Carrara's Spotlight Synthetic Aperture Radar book, it appears that after various compensations, a direct 2D fft can ...
0
votes
1answer
90 views
Google Earth Engine - Blend Sentinel-1 SAR Images?
Does anybody know why I am getting these strips across my Sentinel-1 images and how to fix it?
I am using multiple images over Mozambique between January 1st and January 13th.
I want to use this ...
3
votes
0answers
131 views
Histogram matching in Google Earth Engine?
Does anyone know if there is a more GEE-friendly way of achieving this? I'm experimenting with S1 SAR image histogram matching in GEE and was wondering if foremost the code can be improved. Read here ...
0
votes
1answer
54 views
Calibration annotation data for Sentinel-1 images downloaded from Sentinel Hub?
I received some Sentinel-1 tiff images that were downloaded via the WCS service, so they're just the tiff files, not the full SAFE-format products. They're for the IW GRD product, and my ...
4
votes
1answer
50 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 ...
2
votes
1answer
684 views
SAR processing using Python
I would like to batch process Sentinel-1 images in Python.
Previously I have used SNAP (Sentinel-1 Toolbox) to apply Calibration, Multilooks, Speckle Filters, Terrain Correction and then export as a ...
0
votes
0answers
36 views
Projecting SAR GeoTIFF in azimuth & slant range coordinates
I'm newish to SAR imagery. We have SAR imagery generated from an airborne SAR platform that we are sharing with partners. We have been feeding them geotiffs of the imagery in WGS84 and EPSG:3857 for ...
0
votes
0answers
49 views
SAR processing - geocoding shapefile which is slant range
Is there any software (like snap, sarscape etc.) can be used to geocode shapefile (slant range) to shapefile (ground range) (like WGS84)?
If yes, which data is need for that?
By the way, the ...
0
votes
1answer
123 views
GDAL: Using gdallocationinfo on a rotated SAR image to get pixel value at Coordinates
Some information: I must not re-sample the image, the pixels are rotated, and the image opens in Arcmap just fine.
now, there are 15 GCPs on the raster (which make the pixels rotate)
Progress:
1.When ...
2
votes
2answers
852 views
How to mosaic multiple Sentinel-1 images in SNAP software?
I am trying to mosaic multiple sentinel sar images in esa snap software. The scenes are acquired from two adjacent tracks. I used the tool S1 slice wizard in snap under radar tool menu. But my images ...
5
votes
1answer
1k views
How to visualize inundation using Sentinel 1 SAR Data?
I am trying to visualize flooding after hurricane Harvey that made landfall on August 25-26 2017.
Based on this video, I've been able to obtain the basics of Sentinel-1 SAR imagery. Sentinel 1 comes ...
6
votes
1answer
183 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
votes
1answer
90 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
1answer
200 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 ...
3
votes
0answers
142 views
Understanding difference between collocation and coregistration?
I'm a little confused on this topic. I need to put 2 SAR images into same coordinate grid.
In ESA SNAP tool, there are 2 options:
coregistration: Radar->Coregistration->Coregistration
collocation: ...
1
vote
1answer
79 views
SAR spectral signatures for oil spill detection from different sensors
I have a rather general question about supervised classification for oil spill detection. I want to apply supervised classification on the ESA SNAP dark spot detection tool results. My question is: if ...
0
votes
2answers
157 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 ...
