Groundbased instrumentation for measurements of atmospheric airglow
A groundbased instrument to measure the Atmospheric airglow of the molecular oxygen infrared atmospheric band emission was designed, built, tested and operated. The two channel photometer constructed was based on the original design by Evans (1967) that had been used in balloon experiments. The two channel photometer system specifications are presented. The major difference between the presented design and the earlier two channel photometers is the detector. An Indium Gallium Arsenide (InGaAs) photodiode provided better signal to noise in the conversion of the infrared light signal to an electronic signal than the previously used Lead Sulphide (PbS) detectors. The completed instrument was tested to determine its performance characteristics. Through these tests it was found that the photometer output offset is sensitive to ambient temperature fluctuations. An analysis of the instrument noise was done in an attempt to explain this sensitivity. The output noise performance was characterized and is presented together with the absolute brightness and wavelength calibrations. Data was collected with the instrument in Saskatoon, SK and Eureka, NU. After an initial observation campaign in the high arctic (Eureka, NU) modifications were made to the environmental housing of the instrument in order to improve the scientific value of the data collected. The collected data was processed and a simple analysis performed to demonstrate the capability of the photometer to measure the infrared atmospheric airglow. The collected data can be used to determine the mesospheric ozone height profile. The required data analysis to do so is beyond the scope of this presentation. However, the presented data does demonstrate that the designed and constructed two channel photometer can make the necessary measurements.
ozone, molecular oxygen, TOP2000, Lock-In amplifier, InGaAs, photometer
Master of Engineering (M.Eng.)