A Flexible Preprocessor for ERTS MSS Data

Abstract

The requirements to preprocess Earth Resources Technology Satellite (ERTS) multispectral scanner (MSS) data from its 24 channel tape format at real time rates can be met most efficiently by a parallel processor with a flexible interface for compatibility with a wide range of digital computers. The ability of the preprocessor and tape unit to playback data at programmable rates (real-time and half and quarter real-time) provides the additional ability to adjust preprocessing rate to optimize system throughput for several image processing computer system configurations, and processing modes. The MSS Data Interface described in this paper has been developed to meet these requirements for ERTS processing facilities of those nations which record ERTS data in the NASA-compatible format on 28 channel tape units. The first MDI which has been delivered to the Brazilian government is compatible with the Digital Equipment Corporation PDP-11 computer and can be operated in either a single or dual processor system configuration.