Daytime Electronic Stellar Imaging

The Phase II program will develop and test in the field the hardware prototype of the Automated Celestial Navigation System (ACNS), which provides a secondary means independent of GPS for navigation of ships and aircrafts. In this program we will design and build a single-aperture sensor mounted on an equatorial astronomical mount and a multi-aperture strap down sensor system without moving parts, as well as evaluate design changes for a deployable unit. The first sensor will be used to measure the star limiting magnitude and probability of detecting stars. The second sensor will be used to measure the accuracy of a celestial fix. The multi-aperture unit views three areas of the sky separated by 120 degrees in azimuth using a single focal plane array, detects and identifies stars, and calculates three celestial lines-of-positions (LOPs) and a celestial fix. The sensor operates autonomously and delivers a latitude/longitude fix every 6 seconds with position error of less than 100 m. The sensor software includes a background subtraction and a SNR enhancement algorithm, star catalog, star pattern recognition software, software for mapping of the instrument axis, algorithm for computation of the LOPs and celestial fix, and low-level instrument-control code. The field test will demonstrate that the hardware prototype of the ACNS meets all the performance goals.