Why apply orbit?

s1tbx
#1

Hi!

I read from the help document, it writes “The orbit file provides accurate satellite position and velocity information. Based on this information, the orbit state vectors in the abstract metadata of the product are updated.”

Then I am wondering when will the orbit files are used, during the Radiometric Calibration or Terrain Correction? But After I applied orbit files, I didn’t find any difference of DNs. What did it change after updating the orbit files?

Thank you!

#2

As you already quoted, “the orbit state vectors in the abstract metadata of the product are updated”. Accurate orbits are needed during precise geometric operations, for example terrain correction.