Apr 13, 2021 Junchang Ju & Brian Freitag

This repo maps S2 tile ids to Landsat WRS Path/Rows for HLS L30 data production.

1. Input parameters for the code are provided in the s2_l8pr_params.json file and includes the following mandatory fields:

   1. s2_tile_url: This is the github url to the list of S2 tile ids that define the global land coverage of the HLS data products default: "https://raw.githubusercontent.com/NASA-IMPACT/hls-land_tiles/master/HLS.land.tiles.txt"
   2. kml_s2_url: The URL to the Sentinel-2 grid KML file provided by ESA default: "https://sentinel.esa.int/documents/247904/1955685/S2A_OPER_GIP_TILPAR_MPC__20151209T095117_V20150622T000000_21000101T000000_B00.kml/ec05e22c-a2bc-4a13-9e84-02d5257b09a8"

   The ascending and descending path/row shapefiles are required for the intersection code. These shapefiles for the WRS-2 grid can be found here (made available by USGS): "https://www.usgs.gov/core-science-systems/nli/landsat/landsat-shapefiles-and-kml-files" 3) ascending_shapefile: The local file path to the ascending Path/Row shapefile provided by USGS Note: Only ascending path/rows intersecting 65N and north are included in the intersection code. These path/rows 65N and above can have valid daytime scenes during northern hemisphere summer. The remaining path/rows are nighttime scenes that are not useful for HLS applications. 4) descending_shapefile: The local file_path to the descending Path/Row shapefile provided by USGS Note: All path/rows in the descending shapefile are included in the intersection code. 5) s2_l8_outfile: The output file for the Landsat Path/Row and Sentinel-2 tile intersection information

2. The expected format of the s2_l8_outfile should be a space-delimited file with a header row, followed by the intersection data.

Example:

PathRow S2TileID S2ULX S2ULY PercentOfS2
001002 28XEQ 499980 9000000 9.2
001002 29XMK 399960 9000000 13.5
001003 27XWH 499980 8800020 3.9
001003 27XWJ 499980 8900040 4.1
001003 28XDN 399960 8800020 15.8

3. Included in the repo is a script to convert the KML files to GeoJson files for viewing in geojson.io. This is in the utils folder in the convertKMLtoGJ.py file. This file leverages the s2_l8pr_params.json file in the parent directory and requires an input argument variable (s2 or l8pr) to determine which geojson to convert.