On-orbit commissioning of the ACE-FTS instrument

摘要

The Atmospheric Chemistry Experiment (ACE) is the mission selected by the Canadian Space Agency for its science satellite, SCISAT-1. ACE consists of a suite of instruments in which the primary element is an infrared Fourier Transform Spectrometer (FTS) coupled with an auxiliary 2-channel visible (525 nm) and near infrared imager (1020 nm). A secondary instrument, MAESTRO, provides spectrographic data from the near ultra-violet to the near infrared, including the visible spectral range. In combination the instrument payload covers the spectral range from 0.25 to 13.3 micron. A comprehensive set of simultaneous measurements of trace gases, thin clouds, aerosols and temperature will be made by solar occultation from a satellite in low earth orbit. The ACE mission will measure and analyze the chemical and dynamical processes that control the distribution of ozone in the upper troposphere and stratosphere. A high inclination (74 degrees), low earth orbit (650 km) allows coverage of tropical, mid-latitude and polar regions. The ACE/SciSat-1 spacecraft was launched by NASA on August 12th, 2003. This paper presents the on-orbit commissioning of the ACE-FTS instrument. Various steps were required to safely and progressively activate each module and sub-system of the instrument. This paper describes each step and its relation with the health and safety of the instrument. The overall strategy and sequence of the commissioning activity is presented. Commissioning results are presented in terms of validation of instrument functionality from an engineering perspective. The characterization of the detector contamination is described as well as methods that were developed to mitigate this issue.