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The development and validation of command schedules for SeaWiFSAn automated method for developing and assessing spacecraft and instrument command schedules is presented for the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) project. SeaWiFS is to be carried on the polar-orbiting SeaStar satellite in 1995. The primary goal of the SeaWiFS mission is to provide global ocean chlorophyll concentrations every four days by employing onboard recorders and a twice-a-day data downlink schedule. Global Area Coverage (GAC) data with about 4.5 km resolution will be used to produce the global coverage. Higher resolution (1.1 km resolution) Local Area Coverage (LAC) data will also be recorded to calibrate the sensor. In addition, LAC will be continuously transmitted from the satellite and received by High Resolution Picture Transmission (HRPT) stations. The methods used to generate commands for SeaWiFS employ numerous hierarchical checks as a means of maximizing coverage of the Earth's surface and fulfilling the LAC data requirements. The software code is modularized and written in Fortran with constructs to mirror the pre-defined mission rules. The overall method is specifically developed for low orbit Earth-observing satellites with finite onboard recording capabilities and regularly scheduled data downlinks. Two software packages using the Interactive Data Language (IDL) for graphically displaying and verifying the resultant command decisions are presented. Displays can be generated which show portions of the Earth viewed by the sensor and spacecraft sub-orbital locations during onboard calibration activities. An IDL-based interactive method of selecting and testing LAC targets and calibration activities for command generation is also discussed.
Document ID
19950010834
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Woodward, Robert H. (General Sciences Corp. Laurel, MD., United States)
Gregg, Watson W. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Patt, Frederick S. (General Sciences Corp. Laurel, MD., United States)
Date Acquired
September 6, 2013
Publication Date
November 1, 1994
Publication Information
Publication: Third International Symposium on Space Mission Operations and Ground Data Systems, Part 1
Subject Category
Space Communications, Spacecraft Communications, Command And Tracking
Accession Number
95N17249
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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