System Overview: Sperry Marine MK 39 Ring Laser Gyro AHRS
The Sperry Marine MK 39 is a military-grade, high-precision Ring Laser Gyro (RLG) Attitude and Heading Reference System (AHRS) designed for naval surface combatants, hydrographic survey ships, cable layers, and high-specification dynamic positioning (DP-3) offshore vessels. Engineered by Sperry Marine (Northrop Grumman), the MK 39 delivers instantaneous alignment, true geographic north determination, and accurate 3D attitude measurements (roll, pitch, and heave) without any mechanical spinning rotors or flotation liquids.
Operating on the optical Sagnac effect, the MK 39 Mod 3 and Mod 4 variants provide exceptional tactical heading accuracy (< 0.1° secant latitude) and pitch/roll accuracy (< 0.05°) even during high-G combat maneuvers, missile launches, and violent sea state transitions.
Technical Specifications: Sperry MK 39 AHRS
| Parameter | Specification Details |
|---|---|
| Core Sensor Technology | Triaxial Ring Laser Gyroscope (RLG) + Triaxial Quartz Accelerometer Pack |
| Alignment Mode | Self-contained gyrocompassing (reaction time < 5 min dockside / < 15 min at sea) |
| Heading Accuracy | ≤ 0.1° RMS secant latitude (pure inertial free-run) |
| Roll & Pitch Accuracy | ≤ 0.05° dynamic RMS over full ±45° range |
| Heave Measurement | 5 cm or 5% whichever is greater (essential for multibeam sonar & crane stabilization) |
| Data Interfaces | Dual MIL-STD-1397 (NTDS), Ethernet (IEC 61162-450), RS-422 NMEA 0183 ($HEHDT, $PASHHR) |
| Update Rate | Up to 100 Hz / 200 Hz continuous high-speed attitude output |
| Power Input | 115 V AC (47–440 Hz) single-phase or 24 V DC secondary input |
| Environmental Standards | MIL-STD-167 vibration, MIL-STD-901D high-impact shock, MIL-STD-461 EMI/EMC |
MK 39 Core Subsystems & Spares
| Subsystem / Module | Part Reference | Function & Technical Description |
|---|---|---|
| Inertial Sensor Assembly (ISA) | MK39-ISA-RLG | Hermetically sealed triaxial RLG block and accelerometer core |
| System Electronics Unit (SEU) | MK39-SEU-MOD4 | High-speed navigation DSP processing Kalman filters and sensor corrections |
| Power Conditioning Unit (PCU) | MK39-PCU-MOD3 | Precision low-noise military power filter and voltage regulation board |
| Control & Display Unit (CDU) | MK39-CDU-MIL | Ruggedized wheelhouse/combat system display and control panel |
| Serial / Synchro Interface Card | MK39-IF-422 | High-speed multi-channel serial output and synchro emulation card |
| Internal Shock Isolator Set | MK39-ISOL-M901 | Elastomeric shock mounts tested to MIL-STD-901D grade A requirements |
Seanav Naval & Offshore Service Support
Seanav Marine provides specialized shore-side and onboard field engineering support for MK 39 installations worldwide:
- BITE Diagnostic Analysis: Interrogating Built-In Test Equipment (BITE) logs, laser intensity levels, dither motor performance, and accelerometer bias drifts.
- Kalman Filter GPS Integration: Calibrating external speed log and GPS/GNSS position coupling for extended inertial holdover.
- DP System & Sonar Interfacing: Configuring high-speed NMEA and binary attitude telegrams for Kongsberg, MTU, or Wärtsilä Dynamic Positioning controllers.
- Power Conditioning Inspection: Testing DC ripple suppression, internal surge protection modules, and emergency switchover circuits.
Related Gyro Compass Service resources: Gyro Compass Service hub · GEM Elettronica Polaris FOG-100 Gyro Compass: Solid-State Naval Specs, PCBs & Spares · Alphatron AlphaMidiCourse Mk2 Gyro Compass: Wheelmark Specs, PCBs & Spares Directory · Alphatron AlphaMiniCourse Gyro Compass: Compact Commercial Specs, PCBs & Spares · Teledyne TSS Meridian Surveyor Gyro Compass: High-Precision Hydrographic Specs & Spares · Teledyne TSS Meridian Standard Gyro Compass: DTG Architecture, Specs & Spares Guide