For successful daytime imaging and detection, it is extremely important to be able to quantify the solar background noise of the sky in the ultraviolet (UV) to shortwave infrared (SWIR) range of the electromagnetic (EM) spectrum. Daytime sky radiance can be characterized in any direction at any time using the Laser Environmental Effects Definition and Reference (LEEDR) atmospheric characterization and radiative transfer code. Atmospheric information needed for sky radiance characterizations includes temperature, pressure, humidity, and aerosol concentration that is present throughout the atmospheric path. The real- or near-real time atmospheric information can be obtained with satellites, radiosondes, surface weather stations, and particle counts or diagnosing it with numerical weather prediction (NWP). Furthermore, it is necessary to investigate how much real-time information is needed, how difficult is it to obtain, and whether or not some or all of the inputs need to be measured or predicted using NWP. In order to evaluate what is optimal in terms of ease of obtaining necessary data as well as accuracy and speed of the analysis, sky radiance measurements were made for a select number of non-winter days that were sunny and clear and offered varying atmospheric conditions. LEEDR sky radiances were calculated for the given days, times, and telescope look angles for each of the real-time observed surface observations and NWP data as well as all combinations of those inputs. Comparisons were made between the sky radiance measurements and the LEEDR radiance outputs to determine what combinations of real-time observed information produced the most accurate simulated characterizations.
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