I am having a hard time to figure out what this information refers to. It is stated at the product description of Terra MODIS MOD11A1 product (Wan et al.,2015). (from https://lpdaac.usgs.gov/products/mod11a1v006/)
(It is also mentioned at the dataset page of Earth Engine Data Catalog at https://developers.google.com/earth-engine/datasets/catalog/MODIS_006_MOD11A1)
"Above 30 degrees latitude, some pixels may have multiple observations where the criteria for clear-sky are met. When this occurs, the pixel value is a result of the average of all qualifying observations."
From Version 5, temporal averaging was removed from the MOD11A1 products, and they have now LST data by instantaneous observations. I am saying this based on;
For daily MOD11A1 product, in the MODIS LST Products User's Guide of Version 4 products (by Wan Z. (2006) ) there was this information " As latitude increases beyond 30 degrees, the LST value at some grids in the MOD11A1 product may be the average value of LSTs retrieved from multiple MODIS observations in clear-sky conditions in day or night. If LST values from single clear-sky MODIS observations are required for all grids, the MOD11_L2 LST product and MODIS geolation product (MOD03) should be used instead."
Which was changed into "As latitude increases beyond 30 degrees, there may be multiple MODIS observations in clear-sky conditions. In V5 MOD11A1 product, LST values at all grids are from single clear-sky MODIS observations by selecting LSTs in MOD11_L2 files at smaller viewing zenith angles or the LSTs at larger zenith angles but their values being larger by at least 2K" in the Collection-5 MODIS Land Surface Temperature Products Users' Guide (Wan Z., (September 2006).
In this context, I would like to ask if anybody could help with the above information? What type of averaging is being referred to?
