Uncued Detection and Initial Orbit Determination From Short Observations With the Murchison Widefield Array

This article details the latest developments in the use of the Murchison Widefield Array as a passive radar receiver for the surveillance of space. We cover methods developed to incorporate orbital parameters into matched-filter processing to achieve uncued detection without a prior track, and generate accurate detection-level initial orbit estimates. We present the results from a short collection campaign conducting broad surveillance stares, using FM transmitters as an illuminator with a significantly large bistatic baseline length of 600 km. Initial results demonstrate improved performance in the Murchison Widefield Array's detection of objects in typical low Earth orbital regimes, detecting objects with radar cross section of 1 m2 as well as the generation of accurate initial orbital estimates using very short arc detections spanning less than half a degree.