Ground based satellite tracking system

Student: Ryan Turner

Supervisor: John Homer

Category: Engineering Thesis Project - Communications

The aim of this thesis is to investigate satellites capable of producing Earth imagery, and to propose a suitable ground station designed to track a satellite and download imagery of the user's choice. Remote sensing satellites employ a package of instruments and sensors that respond to electromagnetic radiation that is emitted or reflected from all materials on Earth. By sensing in different wavelength bands, it is possible to construct a false colour multispectral image that can be used to indicate vegetation quality, terrain features and water. The red areas in the above image indicate healthy green vegetation.

Small satellites, or microsatellites, launched by Surrey Satellite Technology Ltd have been fitted with revolutionary electronic cameras designed to sense in 3 or 4 different wavelength bands. These cameras produce imagery that is comparable in quality to that obtained from large commercial remote sensing satellites, at a small fraction of the cost.

The remote sensing microsatellites can downlink free images to simple FM ground stations on Earth using the VHF/UHF amateur radio frequency bands. This allows users with appropriate equipment and an amateur radio user's licence to access the satellites and request images. This thesis investigates the communications schemes utilized for the uplink and downlink, so that suitable equipment could be proposed and analysed for the ground station design.