<title>High Throughput Landsat Imagery Film Recorder</title>

Abstract

The Earth Resources Observation Systems (EROS) Data Center is responsible for processing, archiving, reproducing, and distributing satellite and aircraft remotely-sensed Earth imagery data in both film and digital format. Landsat Multispectral Scanner (MSS) and Return Beam Vidicon (RBV) sensor data alone represents a daily recording requirement of 23 billion pixels on 1000 feet of film. New satellites and sensors may double this amount of data within two years. To handle these requirements, the EROS Data Center installed an operational, multi-mode, programmable, high throughput, high resolution laser-beam film recording system directly on-line to the primary digital image processing computer. This system employs an Argon-Ion laser light source, electro-optic modulator, and rotating mirror to expose film in a flat-field line-scanned format at rates up to 400 lines per second. Laboratory-type requirements, such as a geometric fidelity of ± 0.05% and density repeatability within ± 0.05D, are maintained in a high-throughput production environment. To provide for future sensor formats, the scan rate, scanning spot size, film velocity, laser power, and number of overscans are firmware programmable for up to 16 on-line, auto-matically selectable configurations.