Please ensure Javascript is enabled for purposes of website accessibility
top of page

AR51-09  MIL-Spec, GPS Disciplined Time and Frequency Unit

AR51A-09 Image

AccuBeat’s AR51-09 unit is a compact military grade GPS-Disciplined Rubidium Clock which offers excellent stability and accuracy. The unit includes a Rubidium Atomic Standard, which is phase locked to an external disciplining source such as GPS or another external inputs. All outputs are derived from the Rubidium Atomic Standard and maintain highly accurate time and frequency even when GPS reception is interrupted.

The AR51-09 includes multiple Time of Day (TOD) inputs and outputs. The standard unit includes several Have Quick (ICD-GPS-060) Time Code outputs, in addition to more than 20 1PPS outputs (PTTI ICD-GPS-060, TTL and RS-422 formats) for accurate timing making it an essential unit for secure radio communication applications amongst other possibilities. The standard unit also includes Have Quick (ICD-GPS-060) Time Code input for initial time loading as well as 1PPS input for timing synchronization when a GPS signal is not available.


Communication with the unit is via the CLI (Command Line Interface) using RS-232 or RS-422 and the CLI output provides Time, Navigation and status data. Other Time of Day formats are optionally available including NMEA, IRIG B, NTP or PTP.​

AR51-09 Data Sheet pdf

AR51-09 Data Sheet

The AR51A-09 can be synchronized from 3 independent inputs: internal GPS, external GPS and other external independent accurate timing systems. The input synchronization source can be manually selected by the user or set automatically. The standard option of the unit has a LAN interface, which include NTP (Network Time Protocol), and Monitor & Control by UDP or by SNMP.


The AR51-09 is designed for demanding military platforms such as fighter aircraft, helicopters, UAV’s, shipborne, submarine and mobile military  land platforms. The unit is designed for quick installation on a vibration tray or hard mounted with fixing screws.


AR51-09 can be supplied with AccuBeat’s proprietary Anti-Jamming and Anti-Spoofing technology providing additional protection in cases of GPS denial. For further details, please contact us  directly.

Key Features

GPS disciplined Rubidium clock
Frequency Accuracy : 1E-12
1PPS Accuracy: 30ns (RMS)
Multiple outputs: 10MHz, 1PPS, TOD (Time of Day)
TOD protocols: Have Quick, CLI
Inputs: GPS antenna, 1PPS, TOD
Holdover (no GPS): 1µs/24 hrs (typ.), 5E-11/month
Monitor & Control: RS232 / RS422
C/A code GPS receiver
MIL-STD qualification for airborne applications
Compact: 175 mm (d) x 132 mm (w) x 56 mm (h)


▶ P(Y) code GPS (SAASM) receiver – (supplied by customer)
▶  Monitor & Control: LAN (UDP, SNMP)

▶  Vibration Tray


▶ Demanding Military Platforms

▶  Fighter Aircraft

▶  Helicopters

▶  UAVs

▶  Ships

▶  Submarines

▶  Mobile Land Platforms

Contact us to discuss with one of our experts the best off the shelf or fully customized timing solution for your next project.

Other products from this category

bottom of page