Partial performance degradation of a remote sensor in a space environment, and some probable causes

Area of Science:

• Earth observation science
• Remote sensing technology
• Optical instrument degradation

Background:

• The Multispectral Scanner (MSS) on ERTS-1 has shown significant, spectrally dependent performance degradation.
• Both internal and external calibration systems exhibit this decline.

Purpose of the Study:

• To detail the MSS optical system and its performance degradation.
• To analyze degradation as a function of spectral interval and time.
• To investigate potential causes of observed performance decline.

Main Methods:

• Tracing the history of the MSS during pre-launch testing.
• Analyzing performance data across different spectral bands and orbital time.
• Evaluating optical surface contamination as a causal factor.

Main Results:

• Observed spectrally dependent performance degradation in the MSS.
• Evidence suggests hydrocarbon deposition on optical surfaces.
• Postulated polymerization of contaminants due to solar UV exposure.

Conclusions:

• Hydrocarbon contamination polymerized by UV light is a likely cause of MSS performance degradation.
• Increased blue light absorption by contaminants explains observed spectral effects.
• Further investigation into contaminant sources and effects is warranted.