Eritek has developed and validated hard surface and atmospheric scatter models for optical beam propagation.  Continued development of additional capabilities and features to these models has been funded under various Government contracts.

These models have been validated over the last several years under various configurations (ranges, times of day, weather conditions, etc.) with several field tests using a computer automated camera collection and analysis program.

Atmospheric Scatter Models

Eritek’s Matlab-based atmospheric scatter model generates radiometrically accurate frames of the light returned from Mie scatter of aerosols (and Rayleigh molecular scatter) from an optical beam.  The model also handles polarization of the light from the transmitter to the sensor.  The user defines a transmitted beam direction and locates a sensor camera anywhere in 3D space and pointed in any direction.  The model then creates a simulated scene accurately representing the field-of-view of the sensor.

The camera characteristics, sensor characteristics and bandpass filter are also defined.  The user inputs the atmospheric conditions to be modeled, which consists of the concentrations of several aerosol particle sizes along with their complex indices of refraction and the humidity of the air for water vapor absorption.  The program also generates phase functions for each of the particle types providing insight into which particles dominate the scatter for various configurations.

Hard Surface Scatter Models

Eritek has developed a hard surface scatter model that calculates the amount of light scattered off multiple surfaces when an optical beam is directed towards a building.  A combination of specular and nearly lambertian scatter is produced when the laser beam strikes various surfaces.  The geometry of the entire scene is input into the model along with its orientation to the sun.  Background light from the sun, both direct and diffuse, is also calculated.

Please contact our engineering staff for further information.