Planning and Simulating Observations for a Sounding Rocket Experiment to Measure Polar Night Nitric Oxide in the Lower Thermosphere by Stellar Occultation

• Main Author: Thirukoveluri, Padma Latha
• Other Authors: Electrical and Computer Engineering, Bailey, Scott M., Scales, Wayne A., Henderson, Troy A.
• Format: Thesis
• Language: unknown
• Published: Virginia Tech 2011
• Subjects: launch time selection; star selection; rocket experiment; rocket experiment simulation; density retrieval techniques; stellar occultation technique; rocket geometry planning; rocket observation planning; polar night
• Online Access: http://hdl.handle.net/10919/32969; http://scholar.lib.vt.edu/theses/available/etd-05182011-163321/

The objective of this thesis was to select a star for observation and determine the error in the retrieval technique for a rocket experiment to measure lower thermospheric Nitric Oxide in the polar night using stellar occultation technique. These objectives are accomplished by planning the geometry, determining the requirements for observations, window for launch and discussing the retrieval technique. The planning is carried out using an approximated (no drag) and simulated rocket trajectory (provided by NSROC: NASA Rocket Operations Contract). The simulation for the retrievals is done using data from Student Nitric Oxide Explorer. Stars were taken from a catalogue called TD1. Launch times were obtained from the geometry planned resulting from selecting a zenith angle after choosing a maximum occultation height and determining rocket apogee. Window for observing Spica was found to be 20 minutes. The retrieval technique and simulations showed that column densities and volume densities should be retrievable to less than 5% and 20% respectively observing occultation heights 90-120km. The study suggests that choosing a star positioned north w.r.t the observation location gives us more poleward latitudes and larger launch window. Future research can be carried out applying the stellar occultation and retrieval technique to a satellite. Master of Science