TSC has developed the Laser Safety Analysis (LSA) model, a PC-based software tool that allows ocular hazard zones to be readily determined for OAR testing of laser systems. The laser system may be ground-based for ground-to-ground and ground-to-air illumination, or airborne for air-to-ground illumination. Ocular hazards are determined based on the American National Standard for Safe Use of Lasers, ANSI Z136.1.

LSA Ground-To-Air (Airborne Target) Example

The LSA model computes laser irradiance levels (W cm-2) for the specified OAR ground terrain, which is defined in terms of latitude and longitude (lat/lon) extents using a Mercator projection. Standardized digital terrain elevation data is used in determining the laser propagation distance and any terrain shadowing. Computed irradiance levels are compared to the maximum permissible exposure (MPE) irradiance level, which is determined based on the exposure duration, the laser wavelength, the laser pulse width (pulsed lasers), and the laser pulse repetition frequency (pulsed lasers). The wavelength region of 0.1 – 1000 microns is supported (UV/VIS/IR). LSA outputs two-dimensional plots indicating ocular hazard zones overlaid on the OAR test area of interest. For the ground-to-air illumination case, specular reflection is modeled at the aircraft, and for the ground-to-ground and air-to-ground illumination cases, specular reflection is assumed at the target. The LSA model may also be run in a “single site” mode, in which case the laser irradiance level is computed versus time at a specified lat/lon terrain point or at the aircraft for pilot ocular hazard determination.

For more information please download the LSA Model Fact Sheet (PDF)