Technical note | An Azimuth Elevation Survey of DST Group Edinburgh 71 Labs Platform

Abstract

The National Security and Intelligence, Surveillance and Reconnaissance Division of the Defence Science and Technology Group Edinburgh had installed Ultra High Frequency band antennas on the 71 Labs small experimental platform. These antennas were used to test communications to and from an engineering model of a small satellite. This report presents the findings of an azimuth elevation survey to determine the minimum safe elevations for antenna pointing and signal transmission.

Executive Summary 

The National Security and ISR Division small satellite project developed an antenna system and automated antenna tracking software to communicate with the first satellite mission. The original testing mount for the command and control antenna was located on 71 Labs, above the western veranda facing 205 Labs.

The tracking software drives the antenna rotator from horizon to horizon, to maximise the communication duration for each satellite pass. Located in a high traffic area and amongst populated office buildings, there is a potential radiation hazard if antenna pointing is not properly controlled.

On the 16 September 2016, an azimuth elevation survey was conducted at height of 165 cm above the deck on the 71 Labs platform to determine the safe pointing elevations for the antenna system.

The results of the azimuth elevation survey reveal:

1. The tree line (looking north) varies in height, obstructing the clear line of sight to the horizon between 5 or 10 degrees.
2. The tree line beyond 71 Labs saw tooth roofline (looking east) obstructs the line of sight to the horizon by 5 degrees,
3. The height of the skybridge (looking south) obstructs the clear line of sight to the horizon by 7 degrees, and
4. The height of the 205 Labs building (looking west) obstructs the clear line of sight to the horizon by 10 degrees. The closest infrastructure to the antenna site, the concrete stairwell, obstructs the line of sight by 17 degrees.

The best viewing azimuth is between 177 – 182 degrees, looking due south, with infrastructure obstructing view to the horizon by 01°51'33". The best range of viewing azimuth from the 71 Labs platform is 55 - 115 degrees recording 5° elevation or less.

These survey results can be reused for future antenna trials work conducted from the 71 Labs platform.