Calibration of the Ultraviolet Cameras on NASA’s Carruthers Geocorona Observatory

Zhang, Alex

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https://hdl.handle.net/2142/124786 Copy

Description

Title

Calibration of the Ultraviolet Cameras on NASA’s Carruthers Geocorona Observatory

Author(s)

Zhang, Alex

Issue Date

2023-05-01

Keyword(s)

Remote sensing, Exosphere, Optical Sensor Calibration, UV Emission

Abstract

The Carruthers Geocorona Observatory is NASA’s first mission dedicated to investigating the fundamental nature of Earth’s outermost atmospheric layer known as the exosphere. The Carruthers mission’s primary payload is the GeoCoronal Imager, which consists of two co-aligned imagers (channels) for simultaneous, column-volume sensing of ultraviolet emission by exospheric hydrogen atoms. These images will be used to determine the spatial structure and temporal variability of the exosphere on global scales, but a prerequisite of that analysis is isolation of the target emission from instrument and scene backgrounds as well as calibration of the absolute photometric sensitivity of the cameras. This thesis develops the calibration algorithms that will be used for mission data analysis, including: (i) bias and dark current estimation and subtraction, (ii) estimation and subtraction of energetic particle radiation backgrounds, (iii) background photon scene gradient detection and removal, and (iv) flat-fielding. The algorithms are validated using a synthetic image model to measure their accuracy and precision, while laboratory calibration data is used to verify instrument performance against design requirements.

Type of Resource

text

Language

eng

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