Printer FriendlyEmail Article Link

Positioning Application: Why is the GPS minimum received power level -130dBm and not -128.5dBm as per the IS-GPS-200 ?

  • PosApp (SimGEN, SimREPLAY, SimREPLAY+)
  • GPS
  • Spirent simulators were originally designed using the STANAG 4294 specification (see FAQ14115 for further details).
  • The STANAG stated that the minimum received signal strength for GPS L1 C/A code would be -160dBW (-130dBm) for Block I satellites.
  • Spirents GPS simulators were designed to use this as the reference level for all signals.
  • The IS-GPS-200 states that the minimum received level for GPS L1 CA is -158.8 dBW (-128.5dBm) from Block II satellites onwards.  
    • This because the satellites had a higher transmit power level.
  • Spirent did not change the software power levels to reflect this as it would effect all existing customers who had scenarios which referenced -130dBm.
    • Spirent intend to maintain the reference level for GPS L1 CA as -130dBm for all future software versions.   

Product : SimPLEX,SimREPLAYplus,SimREPLAY,SimGEN,PosApp,GPS