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GNSS Receiver Specifications

TSync Time Code Processors are capable of utilizing GPS/GNSS timing signals as an external reference. To this end, all models can be ordered with either an optional internal GNSS receiver, or the TSync PCIe and cPCI models can be configured—at the time of purchase—for use with an external GNSS receiver (integrated into the antenna housing).

Internal GNSS Receiver

All TSync Time Code Processor models are available with an optional onboard GNSS receiver (to be ordered at the time of purchase; factory retrofits may be possible.)

If installed, the board supplies 5VDC through the GNSS receiver to the external antenna via the coaxial cable (antenna and cable are sold separately).

Alternatively, TSync PCIe and cPCI boards can also be operated with an external GNSS receiver (i.e., the receiver is built into the antenna housing). In this case, the board supplies 12 VDC to the receiver/antenna through its data communications cable.

  • Receiver type:
    • 72-channel receiver with concurrent dual-constellation reception; pre-configured to receive GPS/QZSS & GLONASS
    • Supports GPS/QZSS L1 C/A, GLONASS L1, BeiDou B1
      Galileo-ready E1 (subject to firmware upgrade)
  • Acquisition times:
    • Cold start – GPS & GLONASS: 26 s; GPS & BeiDou: 27 s
    • Aided cold start – GPS & GLONASS: 2 s; GPS & BeiDou: 3 s
  • Sensitivity:
    • Tracking & Nav – GPS & GLONASS: -167 dBm; GPS & BeiDou: -165 dBm
    • Reacquisition – GPS & GLONASS, GPS & BeiDou: -160 dBm
  • Timing accuracy, clear sky: ≤ 20 ns
  • Time-pulse frequency: 0.25 Hz – 10 MHz
  • Time-pulse jitter: ±11 ns
  • Time-mark resolution: 21 ns
  • Integrity reports: RAIM active, phase uncertainty time-pulse rate/duty-cycle.
ClosedAntenna Connection

All TSync Time Code Processor equipped with the optional on-board GNSS receiver have a front panel SMA RF connector, through which the signal from, and the supply power to the GNSS antenna (sold separately) are provided (supply power: +5V [±10%] @ 30 mA max).

The RF antenna cable (sold separately) is connected to the TSync Time Code Processor board via a short male-SMA-to-Type-N adapter cable (included), made from RG-316 coaxial cable.

 

Note: The provided cable should be used instead of 3rd party adapter, as it incorporates a strain relief, protecting the connectors.

External GNSS Receiver

PCIe and cPCI boards can be operated with an external GNSS receiver, i.e. the receiver is integrated into the Acutime GG smart antenna unit. (See also Smart Antennas unit.)

A high-density DB-15 connector is used to connect the external antenna (with its built-in GNSS receiver) to the board. With external receivers, cable lengths up to 90 m (300 ft.) are possible.

ClosedElectrical Characteristics, Board to Receiver Transmission

RS-485 Differential Signal:

  • +1.5 V to +2V Common Mode Output Voltage
  • 1.5 V min to 3.3 V max Differential Output Voltage Swing
ClosedElectrical Characteristics, Receiver to Board Transmission

RS-485 Differential Input:

  • -7 V to +12 V common mode voltage input range, 200 mVp-p differential voltage threshold
ClosedElectrical Characteristics, Receiver Power
  • 50 mA @ 12 V provided to power the antenna
ClosedSpecifications, external GNSS receiver
  • Acquisition time:
    • < 4 minutes from a cold start
    • Re-acquisition time: < 2 sec (90%; current almanac downloaded)
  • Frequency:
    • GPS L1 (1575.42 MHz)
    • GLONASS L1 (1602 MHz)
  • Satellites tracked: up to 32 simultaneously
  • Sync to UTC: within ±15 ns to GPS/UTC (1 sigma) (stationary)
  • Sensitivity: -136 dBm (acquisition), -141 dBm (tracking)
  • 1PPS accuracy (1-sigma): <15 ns (stationary mode), <45 ns (mobile operation)
  • Accuracy horizontal position: <6 meters (50%) <9 meters (90%)
  • Accuracy altitude position: <11 meters (50%) <18 meters (90%)

SAASM Receiver

cPCI and VPX boards are compatible with a SAASM receiver for authorized users. Instructions specific to SAASM operation are provided in a separate manual. The SAASM receiver is not compatible with GLONASS.

Receiver type: MPE-S Type II GB-GRAM

Frequency: L1 (1575.42 MHz) and L2 (1227.6 MHz) simultaneous; L1- C/A, P(Y); L2 - P(Y)

Satellite Tracking: 1 to 12

TTFF – Time to First Fix (Synchronization Time):

  • Cold Start (with almanac download): 15 minutes
  • Cold Start (no almanac download): 5 minutes
  • Warm Start: 90 seconds
  • Hot Start: 10 seconds

TTSF – Time to Subsequent Fix (Reacquisition Time):

  • < 20 seconds, Off or Stby < 15 minutes
  • < 25 seconds, Off or Stby < 60 minutes
  • < 70 seconds, Off < 60 minutes

Antenna connector:

  • Convection Cooled: SMA Jack (+3.3 V @ 9 mA to 60 mA)
  • Conduction Cooled: SMB Jack (+3.3 V @ 9 mA to 60 mA)

1PPS accuracy: ±100 ns

Key fill: DS102 standard, DS101 optional

Backup Battery: SAASM I/O connector or P1-VBAT, VPX P1 connector.