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slcp2cod

This repository contains jobs to convert S1-SLCP products to Coherence 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` (Recommended defaults)
`overriding_azimuth_looks`	(Optional) Azimuth looks to override SLCP's range 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` (Recommended defaults)
`min_match`	Minimum number of CODs to created. Priority of creation is based on temporal baseline. (See Notes below)	int	`1` (Recommended defaults)
`min_overlap`	Minimum ratio of overlap between pre-event_SLCP and co-event_SLCP. Should be < 1. (See Notes below)	float	`0.3` (Recommended defaults)

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):

$COD=COR_{preeventslcp}-COR_{coeventslcp}$

where COR = Coherence of given co-registered SLCP

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