Level 1B: Off-Line Software for Sensors on NOAA Satellites
Advanced Microwave Sounding Unit A (AMSU-A)
Earth Location Correction:
The current level 1B earth location system and level 1B format are designed to provide one set of scan geometry and earth location data per instrument processed. This earth location information is used for all channels and thus it must be generic. Significant misalignment errors per channel will result in variations in the accuracy of the earth locations per channel. For the AMSU-A instruments, users have reported that this variation is great enough to make the data unusable particularly when trying to co-register channels or instruments. To correct this problem, additional earth location data is required. To provide enough information in the level 1B data files would mean a major change to the current level 1B format. This is not acceptable at this time. Plans are to correct this problem for future NOAA satellite series. To provide users some means of correcting the earth locations for the current satellites, this page contains a Fortran program that can take the latitude and longitude information from the level 1B and apply corrections to make the values more accurate based on the antenna channel grouping. Please follow the directions in the read me document below to integrate this software into your product processing system.