slcp2cod

This repository contains jobs to convert S1-SLCP products to Coherenece Differences (CODs) for creating Damage Proxy Maps v1 (DPMv1).

A COD is created based on the below pairing system, using 3 SLCs --> 2 SLCPs --> 1 COD:

Associated job:

Job 1: S1 COD - Network Selection

This job does network selection / pairing of pre-event SLCPs with the co-event SLCP in the specified AOI to submit to the S1 COD job (Job 2 below) to create CODs

• Type: Individual

• Facet: Not needed

• User inputs:

  Fields	Description	Type	Example
  dataset_tag	Suffix dataset tag to append at the end of the dataset id for differentiating events or settings	string	'standard'
  project	Project category for possible queue propagation later	enum	'ariamh'
  slcp_version	SLCP version to pair CODs for. Default is v1.2	string	'v1.2'
  aoi_name	Dataset ID of AOI to find SLCPs for CODs creation based on AOI's coordinates, start, end and event time.	string	'AOI_Japan_Earthquake'
  track_number	(Optional) Specific track number (only one allowed) of SLCPs overlapping AOI to process CODs for. If not specified, creates CODs for all tracks overlapping AOI.	int	171
  overriding_range_looks	(Optional) Range looks to override SLCP's range looks to create CODs in the format: subswath1, subswath2, subswath3. If not specified, uses the range looks stored in SLCP for all subswaths.	int,int,int	16,16,16
  overriding_azimuth_looks	(Optional) Azimuth looks to override SLCP's azimuth looks to create CODs in the format: subswath1, subswath2, subswath3. If not specified, uses the azimuth looks stored in SLCP for all subswaths.	int,int,int	4,4,4
  min_match	Minimum number of CODs to created. Priority of creation is based on temporal baseline. (See Notes below)	int	1
  min_overlap	Minimum ratio of overlap between pre-event_SLCP and co-event_SLCP. Should be < 1. (See Notes below)	float	0.7

• Important outputs:

  • No products will be directly generated, only S1-COD jobs will be submitted based on pairing results. (Expect 1 job for each subswath)

• Notes:

  • The COD network selector pairs SLCPs to submit to the S1-COD job based on the following workflow:

    1. Gather pre-event_SLCPs + co-event_SLCPs from GRQ. Search criteria:

       1. SLCPs are pre-event if SLCP_end_time < AOI_event_time
       2. SLCPs are co-event if SLCP_start_time < AOI_event_time < SLCP_end_time

    2. Match pre-event_SLCP and co-event_SLCP pairs if:

       1. pre-event_SLCP[‘master_time’] - co-event_SLCP[‘master_time’] < 1 day
       2. area_intersect(pre-event_SLCP,co-event_SLCP) / area(co-event_SLCP) > min_overlap

    3. Creates and returns minmatch or valid SLCP pairs for COD based on shortest temporal baseline, where

       • temporal baseline = co-event_SLC['slave_time'] - pre-event_SLCP['slave_time']

  Hence, if there are multiple pre-event SLCPs as per the following:

  • If minmatch = 1, only COD 1's job will be submitted
  • If minmatch = 2, both COD 2 and COD 1 will be submitted

Job 2: S1 COD

• Type: Individual

• Facet: Not needed

• User inputs:

  Fields	Description	Type	Example
  dataset_tag	Suffix dataset tag to append at the end of the dataset id for differentiating events or settings	string	'standard'
  project	Project category for possible queue propagation later	enum	'ariamh'
  url1	Pre-event SLCP dataset's s3 url	string	s3://s3-<region>.amazonaws.com:80/ <bucket_name>/datasets/slc_pair/v1.2/ <year>/<month>/<day>/<S1-SLCP_ID>
  url2	Co-event SLCP dataset's s3 url	string	s3://s3-<region>.amazonaws.com:80/ <bucket_name>/datasets/slc_pair/v1.2/ <year>/<month>/<day>/<S1-SLCP_ID>
  overriding_range_looks	(Optional) Range looks to override SLCP's range looks to create CODs for that specific SLCP subswath.	int	16
  overriding_azimuth_looks	(Optional) Azimuth looks to override SLCP's azimuth looks to create CODs for that specific SLCP subswath.	int	4

• Important outputs:

  Product	Description	Example
  Coherence Difference	Geocoded, multilooked CODs. Band 1 - Pre-event SLCP's Amplitude. Band 2 - Coherence Difference (pre-event - co-event).	diff_cor_[burst]_[range_lks]_[az_lks].cor.geo
  Pre-event SLCP Coherence	2-Band geocoded, multilooked coherence (COR) of pre-event SLCP. Band 1 - Amplitude. Band 2 - Coherence.	cor_[burst]_[range_lks]_[az_lks].cor.geo
  Co-event SLCP Coherence	2-Band geocoded, multilooked coherence (COR) of co-event SLCP. Band 1 - Amplitude. Band 2 - Coherence.	cor2_[burst]_[range_lks]_[az_lks].cor.geo

• Notes:

  • The CODs in this PGE are computed as such (from burst_coherence_diff.py):

    

    where COR = Coherence of given co-registered SLCP

    => Positve values correspond to decreased coherence after event and possible damage due to event.