Alphasat and sentinel 1A, the first 100 links

The paper details the approach, sequence, and results of the in-orbit campaign for E/O data relay using the Tesat Laser Communication Terminals from a LEO spacecraft - Sentinel 1A - a part of the EU Copernicus program, to the TDP1 payload of Alphasat, Europe's largest telecommunication satellite. After configuring the LCT́s on both spacecrafts to a standard operating mode in the first 2 month of the campaign, the next few months have been used for testing the capabilities of the systems. Links with transmit powers as low as 100mW over 42000km and links probing the upper atmosphere are examples of this test campaign. In addition, far field laser beam profile and tracking performance measurements have been performed, using the unique capability of the LCT on board of Alphasat to deliver 25kHz sampled data for all internal sensors (tracking and acquisition).