Noam Leiter

Noam Leiter


Daniel Zelazo
Optimizing Cluster Flight for Space-based Geolocation


Optimizing Cluster Flight for Space Based Geolocation


Noam Leiter

Faculty of Aerospace Eng., Technion

Israel Institute of Technology

Work towards M.Sc. degree under the supervision of Prof. P. Gurfil

Space based geolocation with a cluster of satellites performing time

difference of arrival measurements (TDOAs) can provide accurate

tracking of a Mars rover, a redundant navigation system in a jammed

GNNS environment, or a cost-effective system for autonomously locating

distress signals.

Numerous estimation schemes have been used for geolocation with

TDOAs. In this study, it is shown that former methods are highly

sensitive to the initial estimate due to the nonlinear nature of the

hyperbolic TDOAs. This initial ambiguity is solved in the current

research by first applying algebraic methods, borrowed from computer

graphics, to find all possible initial positions. Then, additional

measurements are used to perform multiple model estimation techniques

to statistically distinguish between the true target and fictitious initial


In addition, tight estimation bounds are derived for the multiple model

estimator. These estimation bounds are then used to optimize the cluster

trajectories resulting in optimal positioning performance in several

simulation scenarios.