Earth Observations Division Landsat Imagery Preprocessing System

The Earth Observations Division (EOD) at NASA\u27s Lyndon B. Johnson Space Center (JSC) has recently placed into operation a new system to receive and process the Landsat imagery output of the Master Data Processor (MDP) located at the Goddard Space Flight Center (GSFC). The main purposes of the EOD System are to (1) extract areas of interest (AOI) from full scenes (170 km × 185 km) and (2) provide source data to users of Landsat imagery. The EOD system consists of two major subsystems: Multi-spectral scanner (MSS) imagery reception and AOI extraction. The imagery reception subsystem acquires the data signal transmitted by GSFC to the EROS Data Center over the RCA Domestic Satellite service and monitored by JSC. These data are recorded at JSC on high density digital tapes (HDTS), GSFC also transmits inventory data over telephone lines to JSC, describing the contents of the HDT data stream. The extraction subsystem selects AOI\u27s from the full scenes by comparing the Goddard High-density Inventory Tapes (GHIT) with the users\u27 requests. Then the required full scenes are read from the HDT\u27s and converted from analog-to-digital. The requested AOI is then written to computer compatible tapes for subsequent image analysis