GAMMA Questions

Hi all,
I have some questions concerning the IPTA results, they are quite simple but I need to have some information from you to assess the quality of my results:

- Which is an acceptable geolocation error of PS for the C-band Sentinel-1 data processed at full resolution? According to your sentinel processing experience, how big is your PS geolocation error?

- is the column 'height' produced with the table from disp_prt command, representing the height of the PS reflection above the reference datum or the height of the DTM used for the topographic phase removal?

- why the first acquisition in the time series table is not equal to 0 for all the PS? is this due to the filter which we apply during IPTA which affect the phase of the reference point too?

Thanks!

Alessandro