Suggestions on processing flow for ERS Level 1 IMP Product

Hello everyone,

I am looking for suggestions on processing ERS-1/2 SAR IM Precision L1 Product [SAR_IMP_1P] to Sigma0.

Following are the steps that I currently applied:

  • Apply Orbit File
  • Radiometric Calibration
  • Range Doppler Terrain Correction

Not sure if I miss any important step?

My main concern is that should I apply Remove Antenna Pattern Operator before RD Terrain Correction?

Besides, where can I find the two example XML graphs highlighted in yellow in the following figure (contents from SNAP Version 7.0.4 Help Contents for Range Doppler Terrain Correction):

Any helps will be appreciated!

Thank you in advance~

I think your current work flow is fine. You don’t need to apply Remove Antenna Pattern operator before RD Terrain Correction because Calibration has taken care of everything. The two graphs mentioned in the help have been removed for some reason. The help should be updated. You can create your own graph if you want. I’d suggest you process the product step by step because sometimes it’s faster that way than processing with a graph

Hello @jun_lu,

Thank you for your reply!

Regarding your suggestion on processing step by step faster than a graph, is it, in general, true for any kind of sensor’s data?
I just wonder the efficiency between different processing strategies:

  1. Process step by step using SNAP GUI.
  2. Process step by step using SNAP gpt (which will require “read” and “write” product for every gpt call).
  3. Process with a graph.
  4. Process step by step using snappy (which only needs one-time calling of “read” and “write” product).

My main concern is for Point 2~4 since I usually do bulk processing. Do you have any comment on this?

3 could be slow. All others are similar

I see~
Thank you :smiley: