International Ice Patrol Side-looking Airborne Radar (slar) Experiment 1988

Abstract

During the period 7 through 16 June 1988, the Inter national Ice Patrol conducted an evaluation of the AN/APS-131 Side-Looking Airborne Radar (SLAR). This SLAR, installed as part of the multi-sensor surveillance AIR EYE system onboard the U. S. Coast Guard HU-2SB medium endurance aircraft, was evaluated for.its ability to detect icebergs. The data collection occurred in an iceberg infested area off the coast of Newfoundland, Canada. The fundamental goal of this research was to provide guidance on the ability of the AIREYE-equipped HU-258 to perform the iceberg detection mission of the International Ice Patrol. Specifically, there were two objectives: 1. Determine the optimum altitude for iceberg recon naissance, and predict the probability of detection as a function of sea state, lateral range, and iceberg size. 2. Compare the iceberg detection capability of the AN/APS-131 SLAR with the AN/APS-135 SLAR currently used on the International Ice Patrol's HC-130 long range reconnaissance aircraft. �round truth (Le. iceberg dimensions and positions, and enVIronmental conditions) were collected by the U. S. Coast Guard icebreaker NORTHWIND (WAG8 282). The HU-25 and HC-130 aircraft flew a box pattern around the iceberg search area. Several different altitudes were used. The Ice Branch of the Atmospheric Environment Service of Canada also had two of its SLAR-equipped ice reconnaissance aircraft (an Electra and a Dash-7) participate in the experiment. Results indicate the AN/APS-131, while not having the azimuth resolution of the AN/APS-135, is capable of performing the iceberg reconnaissance mission. These preliminary results indicate an altitude of 4000 to 6000 feet is best for the AN/APS-131 for this mission.Current plans for the 1989 iceberg season are for the HU-2SB to compliment the HC-130H reconnaissance air-craft. Due to its limited endurance, the HU-2SB aircraft will not be able to replace the longer-range HC-130. However, during certain times of the vear and in certain light ice years, the HU-2S8 should be able to conduct the International Ice Patrol mission.