NavFire Carrier

Invocon’s NavFire Carrier (NFC) hosts a BAE Systems NavFireTM GPSR enhancing its interface with nominal +28 Vdc MIL-STD power and RS422 signal conversion.  NavFireTM signals are made available on the NFC’s connectors configurable to suit several use cases such as direct connection to a Flight Computer or connection to both an SDN500 INS and Flight Computer.

Key NFC Features:

  • The NFC provides the necessary mechanical mounting to carry/hold the GPSR while exposing its interfaces. 
  • The bottom of the NFC has two recessed keys which are synched with the keying of the GPSR that are used for aligning to its mounting surface.
  • Power is supplied from an external +28 Vdc nominal power source which is internally EMI filtered and converted to +5 Vdc for the hosted GPSR’s use.
  • The GPSR’s auxiliary power (backup battery) interface is optionally available for use to maintain the NavFireTM’s volatile RAM settings when the primary power is off.
  • Depending on the configuration, the GPSR 3.3V CMOS signals are converted to RS422.
  • The NFC replicates the 1PPS signal from the GPSR to five RS422 outputs as well as to one 3.3V CMOS output.
  • Encryption keys can be loaded through the key loading interface provided via a DB9 connector port. 
  • The hosted GPSR unit can also interface to an externally connected Emcore (Systron-Donner) SDN500-xx76 in a tightly coupled fashion which combines the GPSR information with its internal SDI500 IMU creating a blended INS solution.
Key Interface Specifications
Input Voltage9 – 60 Vdc
Input CurrentTypical 140 mA continous at 28 Vdc
ConnectorsPT02E-8-4P circular for power | DB-9 for key-loading | DB-50 for I/O
Size6.25 x 4.25 x 1.961 inches (including GPS RF connector holdown bracket)
WeightNominal 2.3 lbs
Case Material7075 aluminum Alodine coated
Operating Temperature-24° to +61°C (Acceptance Levels)
GPS RFThe NFC directly exposes the NavFireTM’s L1/L2 RF connectors providing a holdown bracket.
SDN500 InterfaceEnable/Disable of  the NavFireTM’s SDN500-xx76 GPS/INS interface.
Battery Input[Optional] NavFireTM’s battery backup input (+3.45 ~ +5.0 Vdc with 50mVpp max ripple)
Time-Sync MST_CLK[Optional] NavFireTM’s 10.949297 MHz time synchronization signal output at 3.3V CMOS
Time-Sync T20[Optional] NavFireTM’s 50 Hz clock pulse output at 3.3V CMOS.
Spin Pulse[Optional] NavFireTM’s Spin Pulse feature (i.e., Advanced Spinning Vehicle Navigation) configurable as RS422 or GPSR’s native CMOS.

The NavFire™ GPS Receiver is a product of BAE Systems.