Meaning Terrain Correction?
yes, terrain correction at best, given that your area has a suitable DEM for AutoDownload. SRTM is not available in all parts of the earth:
Thank you Sir Still Not possible I tried doing so but the same error persists: java.io.IOException: Can not export geometry. Could not find attribute range_shift.( mul count:0)
anothere workaround: have a look at the file itself, you can open it in MS Excel for example, and make a csv out of it to import it in any GIS.
Yes Sir! am trying that out. But It needs a lot of formatting… Its already in csv format.
Hello Sir!
I tried other data and it gets converted into a point shape file not direction. How to get the flow vector? As u had posted in another question… here Mistakes in Sentinel 1 Toolbox in Offset Tracking
the direction (angle) and the velocity (length) are given in the attribute table of your point file. You can either display your point as a line feature (e.g. an arrow) with a given angle or compute the vectors based on the attributes.
Will Surely Try this !!
Thanks Again
Hello There!
I Wanted to get the azimuth component of displacement using Offset results, which I found in the attribute table of the velocity data which I exported as (arrow) point data. I have given the rotation field as the heading. Is this correct to know the directions and the magnitude(of azimuth only)?
Thanks!
Hi!
Could somebody please tell me a way to remove the outliers (strange pixels) after offset tracking.
THANKS
can you please post a screenshot of your result so we get an idea about the outliers?
So, these two images are the part of one large outlet glacier in Antarctica. I am trying to calculate the montly velocity of this glacier.
In the first image, I want to remove the values more than 2.5 m/day and less than 0 m/day.
Also I want to create a time series analysis of this glacier for the whole year. I have calculated the velocities using the offset tracking and I plan to do the following processes.
- mosaic the two scenes.
- Create stack.
- Using value tool in the Qgis for time series analysis.
Please correct me if I am wrong or missing some steps here.
Thank you.
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you can prevent that already in the operator
Stacking in SNAP is not needed, simply open each date’s img file (in the data folder) in QGIS.
But if you want to remove the pixels afterwards, you can right-click on the raster and select Properties and define a valid pixel expression: Velocity_slv1_24Jun2017_HH > 0 AND Velocity_slv1_24Jun2017_HH < 2.5
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When I tried to remove the pixels, all it do is put whole value between 0 and 2.5 to 1 and rest to null. So, I can’t analyse the variation in the velocity.
don’t enter this expression in the band maths, this creates a binary raster (as this one, 1 where true, 0 where false) .
directly enter it in the valid pixel expression of the Velocity raster. Let us know if it works.
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Hi again!
I tried to mosaic the two scenes using Radar > Geometric > SAR - Mosaic. In the world view, it shows that it has been mosaicked. However, I get the product as shown in the figure. Is there a way to fix that or did I just do it wrong.
uncheck “weighted average of overlap” and “normalize”
It’s still the same result.
what is defined as nodata in your properties? Maybe you have to remove that, save your product afterwards (File > Save Product) and then run the mosaicing again
yes it worked.