slcp2pm (LAR)

SLC Pair to Log Amplitude Ratio

This repository contains jobs to convert S1-SLCP products to Log Amplitude Ratios (LARs) for creating Flood Proxy Maps v1 (FPMv1).

A LAR is created based on the below pairing system, using 2 SLCs --> 1 SLCP --> 1 FPM:

Note: Since SLCP:LAR is 1:1, the pairing of SLCPs is not required to make LARs. Hence, user simply needs to facet on target SLCPs to execute the LAR job on.

Job 1: S1 Log Amplitude Ratio

• Type: Iterative

• Facet: SLCPs to create LARs from

• User inputs:

  Fields	Description	Type	Example
  lar_range_looks	Range looks to create LARs. (Overrides looks in SLCP's metadata)	int	7
  lar_azimuth_looks	Azimuth looks to create LARs. (Overrides looks in SLCP's metadata)	int	2

• Important outputs:

  Product	Description	Example
  Log Amplitude Ratio Products	Geocoded, multilooked LARs	logr_[burst][range_lks][az_lks].float.geo
  Amplitude Products	Geocoded, multilooked amplitudes stored in 2 bands. Band 1 - Master scene's amp. Band 2 - Slave scene's amp.	amp_[subswath][range_lks][az_lks].amp.geo

Notes on S1 Log Amplitude Ratio

The LARs in this PGE are computed as such (from log_ratio.py):

• (Latest) From dataset v2.0 onwards:

  

  where A = Amplitudes of SLCs of the given date in the co-registered SLCPs

  => Negative values / darker pixels correspond to decreased amplitudes in the post-event scene and possible open-water flood.

• Before dataset v2.0 (v1.x etc):

  

  where A = Amplitudes of SLCs of the given date in the co-registered SLCPs

  => Positive values / brighter pixels correspond to decreased amplitudes in the post-event scene and possible open-water flood.

How to use the raw code for standalone use

How to create log amplitude ratio images from ARIA SLC_PAIR products:

1. Go to src.

   ./compile.sh

2. Set environment variables. See set_env_variable.sh for details.
3. Then modify slcp2lar_S1.sh and run it.

Authors

• Sang-Ho Yun - initial work