DECODING CLOUD MASK product from ECOSTRESS Level-2

A tutorial how to use the code ecostress_preprocessing.py to decode the Cloud Mask product from ECOSTRESS Level-2 Documentation of ECOSTRESS L-2: https://ecostress.jpl.nasa.gov/downloads/userguides/2_ECOSTRESS_L2_UserGuide_06182019.pdf

General description

ECOSTRESS L-2 CloudMask is a separate file that could be downloaded besides ECOSTRESS LST & Emissivity products. Information of how to download CloudMask could be found here: https://lpdaac.usgs.gov/products/eco2cldv001/

ECOSTRESS L-2 CloudMask is an 8-bit flag of cloud mask and cloud tests. The general information of each bit could be found in Table 7 of this file: https://ecostress.jpl.nasa.gov/downloads/userguides/2_ECOSTRESS_L2_UserGuide_06182019.pdf

The procedure to decode the 8-bit: (from right- to left)

1. Read the first bit to determine if cloud mask was calculated or not. The cloud mask will not be calculated for pixels with bad or missing radiance data.
2. Read the second bit to determnine if cloud was deteced or not in either of tests 1 and 2
3. If test 1 and 2 fail, final cloud mask could be outcomes of cloud test in bits 1-3
4. If test 1 - 3 fail, using final test in bit 4 is the land/water mask

Instructions

Example data is uploaded in /example/ . The folder contains two files:

ECO2LSTE.001_SDS_LST_doy2019278182133_aid0001.tif : ECOSTRESS LST

ECO2CLD.001_SDS_CloudMask_doy2019278182133_aid0001.tif : ECOSTRESS CloudMask

**A snapshot of ECOSTRESS LST and ECOSTRESS CloudMask **

Example code:

file_cloudmask = 'C:/Users/tvo/Documents/urban_project/ECO_large_04092020_cloudmask/ECO2CLD.001_SDS_CloudMask_doy2019264063150_aid0001.tif'

file_LST = '//uahdata/rhome/Blogging/ECOSTRESS_decode/ECO2LSTE.001_SDS_LST_doy2019278182133_aid0001.tif'

outFile = file.split('/ECO2')[0] + '/decoced/'+file.split('cloudmask/')[-1].split('.tif')[0]+'_decoded.tif'

cloud_mask(file_cloudmask, file_LST, outFile)

Example outcome:

Decoded Cloud Mask overlaying ECOSTRESS LST