Multilateration with the wide-angle airborne laser ranging system: positioning precision and atmospheric effects

Area of Science:

• Geomatics
• Photogrammetry
• Laser Ranging Technology

Background:

• Accurate coordinate estimation is crucial for geodetic applications.
• Airborne laser scanning systems offer efficient data acquisition for ground targets.
• Cube-corner retroreflectors (CCRs) are essential for precise referencing in laser ranging.

Purpose of the Study:

• To assess and optimize the precision of coordinate estimates for ground-based CCRs using wide-angle airborne laser ranging.
• To identify key parameters influencing ranging precision and establish optimal configurations.

Main Methods:

• Numerical simulations utilizing validated models of wide-angle airborne laser ranging systems.
• Analysis of coordinate estimation precision as a function of instrument performance, number of laser shots (LS), and network size.
• Evaluation of the impact of laser beam divergence, aircraft altitude, and CCR density on precision.

Main Results:

• Precision is primarily optimized by instrument performance, number of laser shots, and network size.
• Laser beam divergence, aircraft altitude, and CCR density are secondary parameters when echo count exceeds 20 per LS.
• Vertical precision of approximately 1 mm is achievable under specific conditions (SNR 50, 10-km altitude, 20° divergence, ~5x10³ measurements).
• Atmospheric effects like scintillation and clouds have negligible impact; mesoscale temperature gradients may introduce ~0.5 mm biases.

Conclusions:

• Optimal configuration of airborne laser ranging systems can achieve high-precision coordinate estimates for ground-based CCRs.
• System parameters must be carefully selected to maximize precision, with instrument performance and data volume being paramount.
• Understanding and mitigating atmospheric biases, particularly temperature gradients, is necessary for achieving sub-millimeter accuracy.