MODTRAN Atmospheric Transmission Modeling for Daylight Sensor Site Assessment

Tracking satellites against a bright daytime sky is a difficult endeavor, but Oceanit’s HANDS-IONS (High Accuracy Network Determination System - Intelligent Optical Networks for Space Situational Awareness) camera is designed to do just this. While it will observe, track, and catalog geosynchronous satellites in the daytime, appropriate site conditions are essential for the device’s functionality. By modeling potential sites using MODTRAN, we will be able to identify the optimum locations for the placement of the HANDS-IONS cameras. MODTRAN (MODerate resolution atmospheric TRANsmission) is a computer program designed to model the propagation of electromagnetic radiation through the atmosphere. Archived weather and radiosonde data must be compiled into the proper MODTRAN input format for the desired simulations. In order to assess sites, atmospheric radiance and transmission data output from MODTRAN will be used as input to the IRSNR modeling code to find the signal-to-noise ratio (SNR) of an observed satellite as well as the time it will take to detect a satellite against a bright sky. Analysis of the SNR data from each potential site will allow us to propose sites for the placement of the HANDS-IONS cameras.