The Variation Of Sun Luminance During The Year And Its Effect On The Visible Range Of The Satellite Imaging Time

Abstract

Abstract—This study involves studying the difference in the sun ray luminance at satellite imaging time. Although, it is confirmed time for the same region throughout the year, changing the length of the day and the difference in the luminance of the sun throughout the year lead to different luminance of the sun falling on the earth at the time of imaging.

The remote sensors are often passive  systems, i.e. record the reflected radiations and not sent them as the active systems, so, the brightness of the targets will be effected directly by the luminance of the sun's rays. Any change in the luminance will affect the brightness of the satellite imagery. This change in brightness will affect the recognition or interpretation the time change targets, also affect the visual classifiction.

            The result of this research is a chart showing the sun luminance changing during the year at the satellite imaging time, and then conversing it to an empirical equation, both chart and equation can be used to get the luminance of sun light at any satellite imaging time in the study area. We also added a correcting equation to calculate the effect of day weather on luminance, because it is variable and needs to be measured by recording the weather case on the day and time of imaging.