Hello, I have a problem with the Alos Palsar L1.1 data. I downloaded an Alos Palsar L1.1 scene from ASF and opened it in SNAP. I did calibration, deskewing and terrain correction. But the scene is about 100 meter displaced. I also tried the Orthorectification Tutorial workflow from esa (calibration, multilooking, speckle filter, deskewing, terrain correction) but that leads to an even worse displacement of the scene.
Does anyone have a hint what I could do?
Can you please post the ID of the ALOS product in here?
Or better, a description of the date and location, so we can download the image and test.
The ID is ALPSRP074090290, the date 20070615 and the image scene center coordinates are 15.328, -15.048
I can’t get results for this point and date:
Oh sorry …its the other way round -15.048, 15.328
These are the coordinates of the POLYGON((-15.4009 14.9742,-14.438 14.9742,-14.438 15.7488,-15.4009 15.7488,-15.4009 14.9742))
I downloaded the product and observe a similar shift. Probably, the orbit information is imprecise.
You can try to apply SAR Simulation Terrain Correction instead (use SRTM 1 Sec) and select high cross correlation accuracies. In my case (I only used a subset), this slightly improved the geolocation, although it still not perfect. Worth some trial-and-error runs with different parameters.
Ok I will try this. Thank you.