Description

Objective:The objective of this activity is to add a slow modulation scheme on a high-data rate optical link, so allow efficient daylight sun-background subtraction on the tracking sensor and allow more robust operation at small sun-spacecraft-angles.TargetedImprovements:50% higher link availability at small sun-spacecraft-angles (10 degrees).Description:With incoherent and coherent optical communication schemes the counter terminal needs to be angularly acquired and tracked at sub-arcsecond level before data transmission can be started. This process is susceptible to sun straylight at small sun-spacecraft separation angles, as the light entering the tracking sensor appears at similar frequencies as sun-straylight, close to DC. This activity will introduce sub-modulation schemes on top of the data carrying waveform to allow efficient dynamic straylight suppression. The objective of this activity is to add a slow modulation on a high-data rate optical link, so allow efficient daylight sun-background subtraction on the tracking sensor and allow more robust operation at small sun-spacecraft-angles. This will allow 50% higher link availability at small sun-spacecraft-angles for space-to-ground as well as inter-satellite links.