 It also provides information on which to base a count of objects passing through its detection zone and reports their direction of travel relative to its location.The monitor uses two different [magnetic and passive infrared] sensors and their identification codes to determine direction of travel.Shallow-water operations require generalizing IR imaging to include a non-developmental Thermal Imaging Sensor System (TISS) to surface ships with a day/night, high-resolution, infrared (IR) and visual imaging, and laser range-finder capability to augment existing optical and radar sensors, especially against small boats and floating mines.