Product Name: SC120 GNSS Compass – High-Performance Marine GNSS Compass
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nProduct Overview
nThe SC120 GNSS Compass is a professional-grade, all-in-one heading sensor that provides 0.2° RMS heading accuracy and 0.3° RMS pitch/roll accuracy for critical marine navigation systems. Leveraging multi-constellation GNSS (GPS, BeiDou, Galileo, GLONASS) and advanced carrier-phase decoding, this GNSS compass delivers stable, interference-free true heading for radar, autopilots, ECDIS, AIS, and sonar.
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nWhy Choose the SC120 as Your Primary GNSS Compass?
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nUltra-high accuracy: 0.2° heading (0.1° resolution optional)
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nMulti-constellation: GPS/BDS/Galileo/GLONASS for faster fix and redundancy
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nInertial backup: Built-in gyro and INS provide 1-minute heading output during satellite signal loss
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nDynamic performance: 90°/s turn rate and 20Hz heading updates
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nLow maintenance: No gyro compass spinning parts, virtually zero upkeep
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nFlexible connectivity: Multiple NMEA0183 ports (IEC61162-1 & -2) plus AD-10 and BAM/INS outputs
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Applications for SC120 Marine GNSS Compass

nRadar & ECDIS – Stabilized true motion and overlay
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nAutopilot systems – High-precision heading for course keeping
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nAIS & Doppler sonar – Accurate ship’s heading for target tracking
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nFish finders & plotters – Stable vessel orientation for bottom mapping
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nDynamic positioning (DP) – Redundant heading source for DP1 vessels
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nEquipment List:
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n1. Q: What is the real-world heading accuracy of the SC120 GNSS compass?
nA: The SC120 GNSS compass delivers 0.2° RMS heading accuracy under normal operating conditions. This high precision is achieved through pre-type carrier phase decoding technology and multi-constellation support (GPS/Galileo/BeiDou/GLONASS). For applications requiring even higher resolution, 0.01° heading resolution is available through your dealer.
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n2. Q: Does the SC120 GNSS compass work if satellite signals are lost?
nA: Yes. The SC120 features a built-in high-precision inertial navigation module (INS) and gyro compensation system. If satellite navigation signals become weak or are temporarily lost, the system can maintain heading output for up to 1 minute without interruption. This ensures your autopilot, radar, and other connected systems continue operating seamlessly during short signal outages (e.g., under bridges or near tall structures).
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n3. Q: How fast does the SC120 marine GNSS compass update heading data?
nA: The SC120 provides a heading update rate of up to 20 times per second (20Hz). This high-speed output, combined with a maximum continuous turning rate of 90° per second, makes the SC120 ideal for fast-moving vessels and dynamic applications such as high-speed craft, Doppler sonar, and radar stabilization.
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n4. Q: What NMEA sentences does the SC120 GNSS compass output?
nA: The SC120 outputs a comprehensive set of NMEA0183 sentences through multiple IEC61162-1 and IEC61162-2 ports. Key outputs include: HDT (True Heading), RMC, ROT (Rate of Turn), THS, HCR, as well as ALC, ALF, ARC, HBT. Additional sentences like GBS, GGA, GLL, GNS, GRS, GSA, GST, GSV, HDG, VTG, and ZDA are also available. Proprietary SHR output is available upon request.
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n5. Q: Is the SC120 GNSS compass waterproof and suitable for exposed mounting?
nA: Yes. The SC120 antenna unit has an IP56 protection rating, meaning it is protected against high-pressure water jets from any direction (e.g., deck washing, heavy rain, sea spray) and is dust-protected. It can be mounted in exposed locations on the vessel. The junction box has an IP20 rating and should be installed in a protected, dry environment.
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n6. Q: What constellations does the SC120 multi-GNSS compass support?
nA: The SC120 supports GPS, Galileo, and BeiDou as standard. GLONASS support is available as an option. Using multiple constellations simultaneously provides faster position fixing, better satellite availability in challenging environments (harbors, narrow channels), and improved heading stability.
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n7. Q: How does the SC120 GNSS compass compare to a traditional gyro compass?
nA: Compared to a traditional gyro compass, the SC120 GNSS compass offers several advantages:
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nVirtually no maintenance – No spinning parts to wear out
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nInstant start-up – No 2-4 hour settling time required
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nLower cost – Significantly less expensive to purchase and install
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nNo periodic overhauls – Gyro compasses require bearing replacements every few years
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nTrue heading from satellites – No latitude-dependent speed error
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nBuilt-in attitude – Provides pitch and roll data (0.3° RMS accuracy)
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n9. Q: Can the SC120 GNSS compass be connected to multiple onboard systems simultaneously?
nA: Yes. The SC120 provides 4 NMEA0183 ports total (2 x IEC61162-2 and 2 x IEC61162-1), plus 2 dedicated AD-10 ports for heading output, and 2 BAM/INS ports. This allows you to simultaneously output heading data to your autopilot, radar, ECDIS, AIS, sonar, and other navigation equipment without needing an external multiplexer.
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n10. Q: What is the typical installation location for the SC120 antenna unit?
nA: For optimal performance, the SC120 antenna unit should be mounted:
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nIn a location with a clear, unobstructed view of the sky (360° horizon)
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nHigh on the vessel (e.g., on top of a mast, radar arch, or pilot house roof)
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nAway from other transmitting antennas (VHF, satellite communications, radar) to avoid interference
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nWith the vessel’s centerline properly aligned (or offset programmed)
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nThe IP56 rating allows exposed mounting, but avoid areas subject to physical impact
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nTechnical parameters：
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n1. General
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n2. Interface
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nNote: output the sentence with * requires contact your dealer.
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n3.Environmental conditions
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