S1C relative orbit number formula

Microwave Toolbox
1

Hello.
Does someone know the formula for retrive S1C relative orbit number? On the ESA official wepages seems to be not published yet (only the one for S1B and S1A is present).
I’m trying to process an unwrapped interferograms timeseries with MintPy and it seem that the code still not support S1C. Anyway it seem that it just doesn’t know how to retrive S1C relative orbit number…

2

I suggest to check the official S-1 site maintained by ESA.

3

There had been a discussion on this in this forum before at https://forum.step.esa.int/t/s1c-relative-orbit-number-formula/44851

4

The relative orbit number is directly annotated in the manifest of each Sentinel-1 product.

For instance

      <safe:orbitReference>
        <safe:orbitNumber type="start">58233</safe:orbitNumber>
        <safe:orbitNumber type="stop">58233</safe:orbitNumber>
        <safe:relativeOrbitNumber type="start">61</safe:relativeOrbitNumber>
        <safe:relativeOrbitNumber type="stop">61</safe:relativeOrbitNumber>
        <safe:cycleNumber>347</safe:cycleNumber>
        <safe:phaseIdentifier>1</safe:phaseIdentifier>

Alternatively the formula to compute relative orbit number from absolute orbit number is provided in the Sentinel-1 product specification

in section 3.5.1.1

However only the formulas for S1A/B/C are provided as the product specification did not evolve since launch of Sentinel-1D. (A change is planned)

Waiting for this update the current formulas are provided here

S1-A: Relative Orbit Number = mod (Absolute Orbit Number orbit - 73, 175) + 1
S1-B: Relative Orbit Number = mod (Absolute Orbit Number orbit - 27, 175) + 1
S1-C: Relative Orbit Number = mod (Absolute Orbit Number orbit - 172, 175) + 1
S1-D: Relative Orbit Number = mod (Absolute Orbit Number orbit - 42, 175) +1