Google Earth Engine distributes Landsat 7 image composites of indeces such as NDWI and NDVI that, when averaged on a shapefile, give back a coherent value.
But how is SLC failure treated by it https://landsat.usgs.gov/slc-products-background?
google-earth-enginelandsat-7ndvinormalized-difference-water-index
Google Earth Engine distributes Landsat 7 image composites of indeces such as NDWI and NDVI that, when averaged on a shapefile, give back a coherent value.
But how is SLC failure treated by it https://landsat.usgs.gov/slc-products-background?
Best Answer
The missing data is masked prior to creating the composite. Since the SLC-off line errors are not in the same place for multiple satellite passes you still get a full coverage in the multi-image composite.
See for instance the 8-day EVI composite documentation.
The Landsat-7 Tier 1 data is calibrated to TOA:
You can see the masked stripes of missing data being masked when you display a single image in GEE (i.e. by using the "inspector" tool on masked pixels):
https://code.earthengine.google.com/d72e2444bb77c9d7edc674292fcdc1f2