DTA Looking Into Space
Defence Technology Agency (DTA) has built a small optical space awareness observatory to monitor satellites with the aim of detecting any deviation from the predicted orbit or unusual behaviour.
"New Zealand’s unique geographic location in the South Pacific offers an opportunity to monitor satellite passes that cannot be observed from other locations."
- Having a robust SSA capability in New Zealand offers opportunities for international collaboration, particularly with the UK and Canada.
- Upgraded equipment is ideal for tracking fast moving satellites in low Earth’s orbits in near-real time.
- Capability has been expanded to enable measurement of the brightness of a satellite in four different polarisation planes simultaneously.
Space Situational Awareness (SSA) describes research and activities related to the detection, tracking, cataloguing and identification of satellites orbiting Earth.
New Zealand’s unique geographic location in the South Pacific offers an opportunity to monitor satellite passes that cannot be observed from other locations. Many satellites pass above New Zealand and some geostationary satellites of interest cannot be observed from Europe or North America.
As it offers the possibility for international collaboration, there has been, since 2014, a steady increase in the SSA capability at the DTA. Adjacent to the Ground Station on the Whangaparaoa Peninsula, We have built a small optical space awareness observatory, the capability focus of which is monitoring specific satellites with the aim of detecting any deviation from the predicted orbit or any unexpected variation in brightness which would indicate unusual behaviour or uncontrolled spin.
Precision Equipment
The observatory has a three metre dome and is equipped with a Paramount MEII robotic tracking mount. The optical equipment consists of two 11-inch instruments: an f/10 Schmidt-Cassegrain telescope and an f/2.2 Rowe-Ackermann Schmidt astrograph. A number of cooled CCD cameras are used for imaging, with a maximum field of view of about four degrees diagonal, using a full-frame detector on the f/2.2 astrograph, which is ideal for tracking fast moving satellites in low Earth’s orbits.
Measurement Capability
Several measurements can be obtained from the DTA SSA images. We have developed our own data analysis software, StarView, which has been optimised to work with DTA SSA detectors. These measurements provide accurate positions and brightness levels of satellites passing over New Zealand. More recently, the capability has been expanded by building a specialised polarimetric camera (QuadCam), which measures the brightness of a satellite in four different polarisation planes simultaneously, offering additional information that cannot be obtained from photometry alone.