Sentinel-1 calibration and local incidence angle

s1tbx
#21

Hi @mengdahl,

Thanks for your reply. Since the calibration is applied on the intensity, can I assume that the original phase is preserved?If so, I guess I could apply:
I_beta_cal = sqrt(Intensity_Beta)*cos(phase_original)
Q_beta_cal = sqrt(Intensity_Beta)*sin(phase_original)

Is that correct?

Valentina

#22

Hi Valentina,

Just for my understanding, why do you want a complex version of beta? It has always been assumed that user want to use beta, sigma0 and gamma as a non-complex value.

Peter

#23

Hi @peter.meadows ,

I am studying and exploring the various SAR measurements and looking at the polarimetric properties.
Therefore I need to know I and Q.

Do you know if the phase changes as well, when applying the radiometric calibration?

Valentina

#24

Hi @vale,

Do you know if the phase changes as well, when applying the radiometric calibration?

There is no change in phase when performing radiometric calibration for ESA SAR mission such as ERS, Envisat ASAR and Sentinel-1.

Peter

1 Like
#25

Hi, I have read the document. is the linear interpolation only solution to get the sigma0 value of particular pixels? because the data is arranged such that sigma0 of 40 pixels in 25612 linesā€¦ so i don any idea about how to perform interpolation ?
Help in this regardā€¦
Already i have disussed the same but i keep on trying to get the sigma0 of 4*4 pixels and its DN valuesā€¦

#26

if you want to reduce the radiometric distortions caused by topography you can also calibrate to Beta0 in SNAP and then use the Terrain Flattening operator.