The Sentinel missions

The Sentinel missions mark a new era in Earth observation focusing on delivering a wealth of operational data for decades to come. The six different Sentinel missions carry a range of state-of-the-art technologies to supply a stream of complementary imagery and data tailored to the needs of Europe’s environmental monitoring Copernicus programme. 

Sentinel-1 is a polar-orbiting, all-weather, day-and-night radar imaging mission for land and ocean services. In the ESA web pages, there are many interesting uses and stories about the findings from space through the Sentinel family. Read more: ESA - Copernicus

Sentinel-1 satellites 

DA-Group has made a significant contribution to the Sentinel-1 satellites by delivering  key subsystems and instruments. The Sentinel-1 A and B satellites have been successfully operating since their launch in 2014 and 2016, respectively. We were awarded the subsequent contract for the Sentinel-1 C and D satellites. DA-Group performed the work as a subcontrator to Airbus Defence and Space UK, Airbus DS GmbH and OHB.

• Transmit Gain Unit (TGU)
  This is a dual redundant, highly stable pulsed power amplifier used to provide the transmit signal power to feed the active transmit antenna array. It achieves exceptional stability, between pulses and within  pulses, over the operating temperature range, using an FPGA bias  control, monitoring semiconductor temperature and power levels.
  
  
• Mission Dependent Filter Equipment (MDFE)
  This accurately defines the radar transmit and receive bandwidths, avoiding external interference.
  
  
• RF Distribution Network (RFDN)
  This is implemented as divider (transmit) and combiner (receive) trees providing signal coupling between the radar electronics and the antenna radiating elements. It comprises ~100 divider/combiner units and almost 1,000 interconnection cables. A phase balance of less than 20 degrees, across the 140 radiating elements, was achieved using ultra-stable silicon-dioxide cables. DA-Group also developed the system for measuring and selective matching of cables and units.
  
  
• SES RF Harness 
  A further signal path extension of the RFDN, within the Radar Electronics system.