Equipment & Software for Geophysical Surveys: Design, Manufacture, Support, Supply

Marine Horizontal Transverse Gradiometer MariMag HTG

Main features:
  • High sensitivity and accuracy
  • Built-in compass, accelerometer, leak detector, pressure and humidity sensors
  • Optional altimeter
  • Data collection on a recorder or PC
  • Floating or sinking cable
Price : on request
Гарантия лучшей цены
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MariMag HTG is a modern marine horizontal transverse gradiometer operating on Overhauser effect designed to perform geophysical, geotechnical and exploration works both in shallow and deep water. The device allows to measure the magnetic field gradient with high accuracy using two independent sensors. Each gradiometer gondola can be used as a separate towed magnetometer.

The gradiometer consists of two magnetometer-gondolas, a Y-cable and an aluminum frame with a rear wing and transverse stabilizers. The modular yet rugged design allows ease of carrying the gradiometer and has low drag in the water. The front wing easily adjusts the depth of the gradiometer to the required one even with short lengths of tow cables. A built-in pressure sensor, digital compass and accelerometer allow real-time gondola position calculation, while an optional altimeter provides towing depth in term of distance above seabed.


Overhauser sensors used in MariMag HTG do not require orientation during operation and are maintenance free for 10 years. The modular principle of MariMag makes it easy to assemble towed magnetometer-gradientometers of various configurations with an almost unlimited number of sensors.

Work without base station

Working with transverse or longitudinal gradiometers allows to take into account variations in the magnetic field in real time, in contrast to standard hydromagnetic survey with base station, where variation is taken into account only during post-processing of data from the field magnetometer and magnetic base station.

Management and Data Acquisition Software

The software sets the device configuration and measurement parameters, displays the values of the modulus or magnetic field gradient, controls the operation of the device during the survey and visualizes its spatial position in real time. Also, it chooses which GNSS should be used – internal or external.

The module of survey design creates a network of observations with the option to download profiles in KML format or manually, plan the ship's route to a given profile and navigate along it, place marks and control points comments, as well as download and visualize maps in KML format, as a raster Google images or satellite imagery.

Cables, reels and winches

We have thought of different use scenarios and have developed a sinking cable for hydromagnetic surveys, a floating cable for near-surface hydromagnetic surveys, and a steel cable for towed magnetometers or gradiometers. For the convenience of the device use, we offer reels with a slip-ring, winches with slip-ring and electric drive, high-speed deck winches with slip-ring, electric drive, cable layer and a cable counter.

Areas of use:
  • UXO detection
  • Pipelines and cables detection and inspection
  • Archaeological research
  • Ecological research
  • Engineering surveys
MariMag HTG gradiomenter includes
  • MariMag magnetometer – 2 pcs
  • Weight – 2 pcs
  • Transverse frame – 1 pc
  • Y-cable – 1 pc
  • Recorder with built-in GNSS – 1pc
  • Power supply with charger – 1 pc
  • Power cable – 1 pc
  • 100 ÷ 240 VAC power supply – 1 pc
  • Ethernet сable – 1 pc
  • Deck cable (70m) – 1 pc
  • Data acquisition, visualization & control software – 1 pc
  • Shipping/storage case – 1 pc


Dynamic range

18 000 to 120 000 nT

Absolute accuracy

0.1 nT

Sensor sensitivity

0.01 nT

Counter sensitivity

0.001 nT


0.001 nT

Heading Error

0.1 nT (180°)

Gradient tolerance

30 000 nT/m

Max sample rate

5 Hz



Power supply

12 ÷ 30 VDC or 100 ÷ 240 VAC

Weight in air

11 kg

Operation limitations

Operation temperatures

-20 ÷ +60°C

Storage temperatures

-40 ÷ +70°C


3 000 m


300, 1 000 or 3 000 m

Tow cable

Breaking strength

2 500 kg

Outer diameter

13 mm

Weight in air

125 g/m

Weight in water

46 g/m

Floating cable

Breaking strength

2 500 kg

Outer diameter

20 mm

Weight in air

250 g/m

Weight in water

-20 g/m