LT-1 Geocoded GeoTIFF Production Update (2026-06-28)

Decision

The LT-1 production button must produce a usable geocoded GeoTIFF, not only prepare LandSAR Input_Data for later D-InSAR work.

The current implemented production path is:

LT-1 source asset
  -> radar_data record
  -> SAR_SCENE_PREPROCESS job
  -> lt_gamma single-scene pipeline
  -> SARSceneGeoORM.analysis_tif_path = analysis_ready.tif

This is the platform's real LT-1 single-scene backscatter image product for now. It performs the Gamma single-scene preprocessing chain: LT source product to Gamma SLC, multilook amplitude, geocode, speckle filtering in the linear-power domain, dB conversion, and analysis-ready GeoTIFF registration.

The chain must not silently fall back to unrelated DEM sources. The default production contract is SRTM-derived on the current server:

SAR_ANALYSIS_DEM_PATH=D:\DEM\SRTMDEM_RSP_SARscape.wgs84
SAR_ANALYSIS_TARGET_GRID_SIZE_M=30.0
SAR_ANALYSIS_DEM_RESOLUTION_M=30.0
SAR_ANALYSIS_RANGE_LOOKS=6
SAR_ANALYSIS_AZIMUTH_LOOKS=5
SAR_ANALYSIS_SPECKLE_FILTER_ENABLED=true
SAR_ANALYSIS_SPECKLE_FILTER_METHOD=lee
SAR_ANALYSIS_SPECKLE_FILTER_SIZE=5
PYINT_GEO_INTERP=1

The runtime clips the configured SRTM-derived DEM to the scene footprint with a small margin, converts that clip to Gamma DEM format, runs generate_rdc_dem.py, geocodes the multilooked amplitude with geocode_back, exports a GeoTIFF with data2geotiff, applies a Lee speckle filter to the linear power raster, then converts power to dB. The output pixel_size_m stored in sar_scene_geo is derived from the GeoTIFF transform; WGS84 degree grids are converted to approximate meters before registration.

Multilook is already part of the Gamma preprocessing path through generate_rdc_dem.py; it is controlled by SAR_ANALYSIS_RANGE_LOOKS and SAR_ANALYSIS_AZIMUTH_LOOKS. Speckle filtering is a separate post-geocode raster operation before dB conversion. The filter manifest records the method, window size, domain, and equivalent number of looks used for the Lee weighting.

For SRTM-derived DEMs, the configured 30 m analysis grid must be translated into Gamma dem_lat_ovr and dem_lon_ovr from the actual converted .dem.par spacing. Do not assume that SAR_ANALYSIS_DEM_RESOLUTION_M=30.0 alone changes the output GeoTIFF grid. A 3 arc-second source DEM with dem_lat_ovr=1 and dem_lon_ovr=1 will still produce about 90 m latitude spacing. The runner now reads post_lat, post_lon, and scene latitude from the converted Gamma DEM parameter file, then writes the derived oversampling into the template before generate_rdc_dem.py.

The previous D:\DEM\HeiLongJiang10M_DEM.tif default is not the production default. It is an interpolated regional DEM and must not be mixed silently with SRTM-derived products. If a future production profile intentionally uses it, the selected DEM and output grid must be recorded in the product manifest.

What Changed

/api/landsar-lt1-production/run queues SAR_SCENE_PREPROCESS jobs with engine=lt_gamma.
Each selected LT-1 source asset resolves to a radar_data scene and produces one independent SARSceneGeoORM record.
Batch mode means batch single-scene GeoTIFF production. It does not create a D-InSAR pair/stack product.
The product list under /api/landsar-lt1-production/products reads from sar_scene_geo, not from result_products.catalog_name=lt1_landsar.
Asset inventory and radar search mark LT-1 assets as produced only when sar_scene_geo.status = DONE and analysis_tif_path exists for the LT-1 lt_gamma profile.

UI And Query Contract

The LT-1 GeoTIFF production UI does not accept arbitrary LT-1 scene directories. Operators must select scanned source assets so each output can be linked back to radar_data and sar_scene_geo.
The UI does not expose a satellite-mode/BIST selector. Acquisition mode should come from scanned source metadata, and the current Gamma single-scene pipeline does not require the operator to choose LandSAR import mode manually.
The production candidate list reuses /radar-data/search with satellite_family=LT1 and source_format=LT1_ARCHIVE, so operators can plan production by acquisition date, administrative AOI, orbit, polarization, and product name.
/assets/sources remains the asset-led inventory view. It is not the main LT-1 production planning surface because it lacks the full image search/AOI workflow.
Items that already have a completed LT-1 GeoTIFF product are shown as produced and are not selectable for a new production task.

What Is Not A Finished Image Product

LandSAR 100016 and 100206 are still useful, but they only prepare/import LT-1 data:

100016 -> LandSAR Input_Data
100206 -> precise-orbit injection for imported XML

Those outputs must not be displayed as "image production complete" and must not block reprocessing as if they were geocoded images.

Open LandSAR Work

LandSAR single-scene geocoded image production may still be possible through 180044, 180016, 200046, or 200016, but the repository does not yet contain a verified parameter chain for those modules. Do not expose those proIDs in the formal UI until a real parameter file and sample run are verified.

5.2 KiB Raw Blame History