Various processing and display techniques were developed to display pack ice properties from data collected with a helicopterborne Video-Laser-GPS Sensor System. The Video Sensor System collects digital video images, laser and radar altimeter profiles with GPS positioning. This report describes the sensors and the analysis performed on data collected in March 1998 and 1999 with the Video System in the southern Gulf of St. Lawrence, Canada. The ice features that can be determined from the video system are ice concentration, surface ice roughness, and ridge, floe and lead size distributions. Real-time display programs now provide quick-look and geo-referenced video plots, and plots of laser ice roughness, GPS flight track positions and flying heights. Further software development is needed to make ridge, floe and lead size distributions, and ice concentration available in real-time for operational use. Further field and analysis work is required to investigate the coherence seen between surface roughness, ridge frequencies and variations in image brightness.
Measurements of pack ice properties are required for scientific studies and for real-time use in support of icebreaking operations. Laser altimeters have been used to collect surface ice roughness data for many years from fixed wing aircraft (Hibler, 1972), and more recently from helicopters (Dierking, 1995). Ice concentration and floe size have been measured from videotape recordings taken with a helicopter-borne downward-looking video camera (Rossiter et al., 1992). This paper describes a helicopter-borne system and its capability to monitor pack ice properties. The system collects laser altimeter and GPS position data, and flame-grabs video images in real-time. The first section of the paper provides a description of the various components in the Video-Laser-GPS System. The second and third sections describe the analysis performed on video imagery collected from the southern Gulf of St. Lawrence, Canada in March 1998 and March 1999.
