24 FEBRUARY 2025 | OUR SCIENCE
DST's Sensing and Intelligence Programme is collaborating with the University of Auckland (UoA): Institute of Marine Science and the Space Institute to understand whether low cost, low tech, passive RADAR reflectors can improve the probability of detection of small marine craft in distress, by space-based Synthetic Aperture Radar (SAR) systems. This research is being done under a programme called SAR4SAR: Synthetic Aperture Radar for Search and Rescue.
Currently, weather conditions, vessel size, and the vastness of the ocean can make it challenging to find small vessels. It is envisaged radar reflectors, deployed by small vessels when in distress, could be detectable by space-based SAR systems, enhancing maritime search and rescue operations and the outcomes for South Pacific fishers lost on the high seas.
SAR technology fitted to Low Earth Orbit (LEO) satellites can “see” the Earth’s surface in night and day, through cloud (or the smoke of wildfires), to provide an unobscured view of our planet, and show changes on the Earth’s surface in detail.
PHASE 2A SEA BASED TRIAL FEBRUARY 2025
Following the successful completion of Phase 1: land-based trial (see below), five reflectors have been down selected for further evaluation. Phase2A of the SAR4SAR trial programme was the first opportunity to deploy the reflectors to the sea surface to test their buoyancy and robustness, and conduct a SAR collect. Earlier this month, the reflectors were deployed from The University of Auckland’s Research Vessel TE KAIHOPARA north of Omaha Beach. Initial results are promising and lessons learnt from this activity will be used to refine the reflector designs for additional sea based testing during Phase 2B in March 2025. Photos from the Phase2A trial can be viewed below.
PHASE 1 LAND BASED TRIAL SEPTEMBER 2024
In late 2024 personnel from UoA and DST installed six COTS and two novel radar reflectors, developed by UoA at the UoA Field Station near Ardmore (South Auckland) for the SAR4SAR phase 1 land trial. The installation involved placing the reflectors at fixed surveyed locations, while space-based SAR systems collect the data over a period of two to three weeks. The trial will evaluate the radar returns of each reflector and which SAR satellite constellations and collection modes are the most viable. The purpose is to de-risk the sea based trials.
The novel radar reflectors are designed to maximise the radar return while being lightweight, compact, and affordable, floating effortlessly on the sea’s surface. They will be easy to store, quick to deploy, and poised to make a real impact. This innovative technology will be a first for the South Pacific region.
It is worth noting that additional high latitude testing of the SAR radar is currently being conducted (March 2025) on Campbell Island as part of HMNZS Canterbury's regular deployment to New Zealand’s sub-Antarctic islands.
