| Summary: | This report discusses software that was designed and developed to process Hydrographic Airborne Laser Sounder (HALS) data tapes. The HALS survey produces tapes containing navigational, heading, altitude, and various housekeeping information, as well as raw laser ranging data from which ocean depths are to be extracted in a post-mission processing mode. The software performs its tasks in four sequential processing passes. Pass 1 processing techniques are based on research results concerning depth measurement bias caused by light propagation in sea water. Pass 2 utilizes computer/operator interactive CRT display techniques for editing purposes and computes position via an interactive process using Sodano inverse formulas. Pass 3 utilizes optimal filter techniques to resolve aircraft altitude, pitch, roll, and sea surface waves via a minimum variance solution on the slant range laser measurement from aircraft to sea surface. Pass 4 also operates via optimal filter theory and is designed to treat both depth error and position error simultaneously.
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