Oxygen Spectroscopy Laser Sounding Instrument for Remote Sensing of Atmospheric Pressure

We report on the design and construction of an Oxygen spectroscopy laser sounding instrument designed to measure atmospheric pressure. The pressure sensing instrument (although useful for many applications) was designed as a calibration channel for a carbon dioxide instrument to meet the science requirements of NASA's ASCENDS Mission. The instrument was conceived and designed with a satellite application in mind so we discuss the requirements this places on the instrument. The instrument concept uses the pressure broadening of spectroscopic lines of the diatomic oxygen A-band to deduce atmospheric pressure. There are many uses for this measurement but we are developing it primarily to make a measurement of the dry mixing ratio of CO2. The CO2 measurement can be affected by changes in atmospheric properties such as humidity, temperature and pressure. We have developed a pulsed, frequency-doubled, fiber laser transmitter for scanning the absorption lines in the oxygen A-band. We will report on the theory of operation, open path measurements made at a test site at NASA's Goddard Space Flight Center, review the current state of the instrument technologies and the necessary steps to bring them to space readiness.