Current version: v7.13, July 2016
The ATOVS and AVHRR Pre-processing Package (AAPP) is supplied and maintained by the NWP SAF. This package processes data from instruments on board the NOAA POES polar orbiting satellites – namely HIRS, AVHRR, AMSU and MHS – and from HIRS, AVHRR, AMSU, MHS and IASI on the European METOP satellites. For these satellites AAPP can ingest and process raw direct readout data. It also processes Sensor Data Record data from the new-generation Suomi NPP satellite, and from the sounders on the Chinese FY-3 satellites.

As its main output, AAPP produces files of quality-controlled brightness temperature or radiance data for each instrument – either separately or mapped to a common field of view. An AVHRR cloud mask can also be generated. If profiles of atmospheric variables are required, the AAPP can be used in conjunction with an inversion package. AAPP radiance data are also used directly as input to variational data assimilation systems at several leading centres for Numerical Weather Prediction.

AAPP development is closely linked to the activities and recommendations of the International TOVS Working Group (ITWG).

Questions for other users and developers can be posted on the AAPP Forum.