Detection in low target to clutter ratio by massive multilooking. Application to the recovery of engine fragments buried in Greenland icesheet

Inhalt:
ONERA SAR system Sethi was involved in April 2018 in the search of engine fragments lost 6 months before by a jet-liner en route over Greenland and later buried under 2m of snow. Their radar echoes were thus attenuated by the propagation through snow and, because of the high backscattering of the surrounding ice, the target to clutter ratio was below 10% at X-band. Though the icesheet clutter is very homogeneous, detection of such low contrasted targets requires a very high level of multilooking to yield significant detection at a false alarm rate compatible to the wide area covered.