Date of Award


Document Type


Degree Name

Master of Science in Space Systems


Department of Aeronautics and Astronautics

First Advisor

Richard G. Cobb, PhD.


A satellite QKD model was developed and validated, that allows a user to determine the optimum wavelength for use in a satellite-based QKD link considering the location of ground sites, selected orbit and hardware performance. This thesis explains how the model was developed, validated and presents results from a simulated year-long study of satellite-based quantum key distribution. It was found that diffractive losses and atmospheric losses define a fundamental trade space that drives both orbit and wavelength selection. The optimal orbit is one which generates the highest detection rates while providing equal pass elevation angles and durations to multiple ground sites to maximize the frequency of rekeying. Longer wavelengths perform better for low Earth orbit satellites while shorter wavelengths are needed as orbital altitude is increased. For a 500km Sun-synchronous orbit, a 1060nm wavelength resulted in the best performance due to the large number of low elevation angle passes. On average, raw key rates of 170kbit/s per pass were calculated for a year-long orbit. This work provides the user with the capability to identify the optimal design with respect to wavelength and orbit selection as well as determine the performance of a QKD satellite-based link.

AFIT Designator


DTIC Accession Number