Jeffrey Bloch (Los Alamos National Laboratory), Richard Rast (Air Force Research Laboratory/DETE)
Keywords: Telescopes, Instrumentation
Abstract:
Large format photon counting imaging sensors with high time resolution provide a unique capability for astrometry and object tracking from a moving or scanning observation platform. These sensors produce an output list of photon event data in X, Y, and Time which can be transformed in a distortion-less manner to any fixed or co-moving coordinate system. In this presentation we will discuss how this capability enables new approaches to space object detection and metric observation over traditional framing sensors such as CCDs using a specific, serendipitous set of observations as an example.
NASA’s Galaxy Explorer (GALEX) ultraviolet astrophysics mission provides this unique opportunity to explore the utility of high time precision imaging photon counting sensors for SSA. The 280 kg GALEX satellite was launched in 2003 by a Pegasus XL rocket into a 690 km circular orbit. GALEX contains a 50 cm NUV/FUV telescope with a field of view of 1.2 degrees and a 5 arcsecond spatial point spread function. Each UV photon detected by GALEX is time stamped to a precision of 5 milliseconds and telemetered to the ground. In this talk we will discuss the results of a study to utilize GALEX X-Y-Time photon list data to explore methods of data analysis to detect and characterize space objects that serendipitously crossed its field of view. We will show the results of how the high precision angle-angle-time GALEX photon data combined with the GALEX satellite s ephemeris can be used to detect a space object and derive a state vector for the object from a single field-of-view crossing in ways very different from traditional framing sensors such as CCDs. Such analysis methods can be applied in general to any photon counting imaging detector system working at any wavelength on any ground, airborne, or space platform.
Date of Conference: September 12-15, 2007
Track: Telescopes and Instrumentation