Laser Rangefinding Techniques for Helicopter Fire Control Applications. Phase II - Nonstabilized Gimballed Laser Concept.

摘要

The concept of employing a non-stabilized gimbal for mounting a laser rangefinder on an AH-1G helicopter was evaluated using existing hardware. The overall results indicate that this technique produced slant range errors of approximately 7% over the altitudes tested (300, 500, 1000, and 1500 feet). The evaluation showed the range error to increase significantly as operational altitude decreased. This is due to angular pointing errors translating into large slant range errors when small grazing angles are incurred. Range errors approaching 15% were projected with this system at 50-100 foot altitudes. It was also determined that the use of first pulse return logic generally produced smaller range errors than last pulse logic. In addition, a reduction in operational airspeed resulted in a slight decline in the range error. In summary, utilization of a non-stabilized gimballed laser rangefinder configuration by the copilot/gunner for helicopter fire control systems was only marginally effective at lower altitudes. The need for stabilization of the pointing system is indicated particularly under nap-of-the-earth (NOE) conditions. The addition of a stabilization capability will aid laser pointing while simultaneously allowing use of magnification to improve target detection, recognition and identification ranges. (Author)