Multilateration with the wide-angle laser ranging system: ranging performance and first ground-based validation experiment

A wide-angle laser ranging system has been developed for high-precision multilateration. A laser transmits short pulses in a widely diverging beam toward a network of cube-corner retroreflectors (CCRs). Returned echoes are detected, amplified, digitized, and timed. Impact of instrumental error sources, atmospheric refraction, and scintillation are discussed. The precision of the correlation method for the estimation of times of arrival and a least-squares adjustment method for the estimation of relative CCR coordinates is studied. Data from several ground-based experiments are analyzed. The positioning precision achieved is of 1-2.3 mm in relative radial coordinates and 1.8-3.8 cm in relative transverse coordinates. Results are consistent with a covariance analysis, demonstrating that, as follows: 1) systematic instrumental errors are well corrected; 2) outliers arising from coincident echoes are properly detected; 3) models for forward and inverse problems and estimation techniques are correct. A numerical simulation program based on these models and techniques can be used for optimizing instrumental aspects, providing extensive simulations in various conditions and processing data from future airborne experiments to which the system is devoted.