Sensor Recommendations

The ANELLO Maritime INS has been successfully integrated with a variety of speed sensors, GNSS antennas, and M-Code receivers. The following recommendations are based on tested integrations and typical maritime deployment requirements.

Speed Sensors

The Maritime INS requires a speed sensor to provide aiding data for optimal navigation performance. ANELLO recommends selecting a sensor that supports the full operating speed range of the vessel.

Paddle Wheel

Recommended Model: Airmar DST-810 (NMEA 2000)

Advantages:

  • Most cost-effective and widely used option for unmanned surface vessels (USVs)

  • Provides continuous water-speed measurements, including during brief vessel planing events

Installation Notes:

  • Available in both thru-hull and transom-mount configurations

  • Thru-hull installation is recommended for best performance

Ultrasonic

Recommended Model: Airmar UDST-800 (NMEA 2000)

Advantages:

  • No moving parts, improving long-term reliability

  • Can provide improved accuracy at low speeds

Considerations:

  • May lose valid speed measurements when the vessel is planing at high speed

Doppler Velocity Log (DVL)

Recommended Model: Nortek Nucleus 1000

Interface:

  • RS-232 with Nortek proprietary output

Advantages:

  • Provides ground-referenced velocity when bottom lock is available (typically within 50–100 m of the seabed)

  • Can also provide speed-through-water measurements

  • Best choice for extended GPS-denied operation when bottom lock can be maintained, such as on UUVs

Considerations:

  • Maximum measurable speed is approximately 10 knots

Speed Sensor Installation Guidelines

  • Ensure the selected sensor supports the full speed range of the vessel

  • Follow the manufacturer’s installation guidelines

  • Mount the sensor near the centerline of the hull whenever possible

  • Avoid obstructions that could disrupt water flow across the sensing element

GNSS Antenna Recommendations

ANELLO recommends using active L1/L2/L5 all-constellation GNSS antennas. The following models have been successfully integrated with the Maritime INS.

u-blox ANN-MB2

A cost-effective all-band active GNSS antenna featuring:

  • 5 m SMA cable

  • Magnetic or screw mounting options

  • IP67 environmental rating

Recommended for:

  • Rapid integration efforts

  • Cost-sensitive programs

Tallysman TW3972

A rugged triple-band GNSS antenna featuring:

  • Permanent-mount design

  • IP69K environmental rating

  • L-band correction support

  • Low current consumption

  • Strong RF filtering

Recommended for:

  • General-purpose maritime deployments

  • Ruggedized installations

Calian VeroStar VSP6337L

A high-performance marine GNSS antenna featuring:

  • IP69K environmental rating

  • IEC 60945 and IEC 61108 compliance

  • Low phase-center variation

  • Strong low-elevation satellite tracking

  • Iridium and Inmarsat interference rejection

Recommended for:

  • High-performance marine navigation systems

  • Challenging RF environments

Antenna Installation Guidelines

  • The Maritime INS supplies 3.3 V bias power for active antennas

  • The antenna baseline must be at least 1 meter; longer baselines improve dual-antenna heading accuracy

  • Ensure clear sky visibility for both antennas

  • Follow any ground-plane requirements specified by the antenna manufacturer

  • Use the same antenna model and identical cable type and length for ANT1 and ANT2 unless otherwise validated

M-Code Receiver Recommendations

The Maritime INS has been successfully integrated with the following external M-Code receivers.

Supported Receivers

  • Collins NavHub 100

  • SFS Valiant Splash

Integration Requirements

The Maritime INS accepts M-Code aiding as external GNSS position and velocity aiding through the receiver’s decoded NMEA 0183 output.

Minimum required NMEA 0183 messages:

  • RMC

  • GGA

  • GSA

Requirements:

  • Message update rate of at least 0.5 Hz

  • RMC must indicate active status

  • Position, date, and time fields must be valid

  • GSA must report a valid 3D fix with finite PDOP, HDOP, and VDOP values

Supported Interfaces

  • RS-232

  • Ethernet using NMEA UDP

RS-232 direct connection is the most common integration method.

Operational Guidance

  • Use keyed M-Code operation whenever available

  • Treat unkeyed or fallback modes as lower-assurance aiding sources

For any questions or concerns regarding external sensors, contact support@anellophotonics.com