GEMMS Monitoring

Oceanographic measurements are a core element of GEMMS business activities. Global Environmental Monitoring Systems is responsible for the installation of systems for the monitoring of the ocean and the marine atmosphere, by state of the art instruments including Acoustic Doppler Current Profilers (ADCP’s), and GPS Tracking Drifters for applications in the marine environment both in Australia and overseas.

Measurements are commonly used in conjunction with GEMMS oceanographic modelling to identify a baseline for the environment for facility design as well as providing ongoing information to refine the understanding of the local environment and forces.

Typical applications include;

  • Port, Harbour & Facility baseline measurements.
  • Facility design criteria measurements.
  • Dredging operations.
  • Structure installation.


In 1998 GEMMS bought the first ADCP, primarily for the purposes of ocean model validation. Since the expansion of the capabilities of ADCP’s to measure waves and turbidity GEMMS has acquired more RDI ADCPs and has expanded it’s’ activities to full metocean activities.

To increase it’s ability to map and understand ocean currents, GEMMS has developed a series of ocean drifters. These drifters report position and time, either by wireless technology to a base station or via satellite to a dedicated website. The satellite drifters provide the capability to map ocean currents from periods of days to several months.

GEMMS now have a wide range of instrumentation, including tide gauges, ADCPs, GPS drifters, current meters, temperature loggers, CTDs, wave buoys, buoy based communications and monitoring systems and a range of meteorological stations.

Real-Time Oceanographic and Meteorological Monitoring Systems

GEMMS have over 20 years experience in the design, manufacture and installation of coastal, offshore and land based environmental monitoring systems. Our systems provide real time data measurement of operational conditions at ports and other mining and offloading facilities throughout Australia.

Our systems are based on a standard design and configuration suitable for most applications but can easily be customised to suit specific requirements. Parameters typically measured include directional waves, through water currents, tides and meteorological parameters. Line tension and structural motions can also be integrated into the monitoring systems.

Typically, the information measured and reported in real time is used for operational decision making including ship loading and scheduling with the data integrated directly to Dynamic Under Keel Clearance Systems (DUKC).



Buoy Features

  • Dimensions.
  • 1.2m diameter.
  • 3.8m overall length.
  • 2.0m draft.
  • Materials.
  • Buoy – steel, coating treated.
  • Keel – steel, galvanised.
  • Superstructure & mast – Aluminium, powder coated.
  • Unpopulated buoy weight of 450kg.
  • Payload capacity of 200kg.
  • Keel pod with adjustable ballast chamber and high strength gambled mooring point.
  • Power supply – typically 150W of solar panels, 150Ahr SLA batteries & MPPT regulator.
  • 3 large sealed integrated equipment compartments, interconnected within buoy.
  • Self contained navigation light with 3 nautical mile range.
  • Optional GEMS TT buoy tracking system.
  • Buoy Applications.
  • Navigation aid.
  • Acoustic & nextG communications buoy for remote monitoring – typically used with GEMSpod system with seabed ADCP or other instrumentation.
  • UHF/VHF communications platform.
  • Directional wave monitoring.
  • Meteorological monitoring.
  • Water quality monitoring.
  • CCTV video security monitoring.


The GEMMS Acoustic Current Meter is the central component of our standard port monitoring system. This system integrates an ADCP (Acoustic Doppler Current Profiler) or an AWAC (Acoustic Wave And Currents) instrument for real time reporting of coastal oceanographic conditions including.

  • Directional Waves.
  • Currents through water column.
  • Sea Levels.
  • Sea temperature.

Using a seabed or pylon mounted instrument, the system measures current speed and direction throughout the water column from seabed to sea surface. In addition, the measured data is used to automatically resolve directional waves and sea levels.

The measured data is typically transmitted via cable, radio modem, NextG or Wireless LAN for display on a monitoring computer to aid in port operations and vessel scheduling.

Coupled to Dynamic Under Keel Clearance (DUKC) software, vessel loading and scheduling can be optimised with the result of reducing operational costs and increasing cargo throughput.

Technical Specifications (typical)

  • 4 beam acoustic 1Mhz.
  • Sensors.
  • Temperature, -4degC to 40degC.
  • Compass and tilt.
  • Pressure, 0-50m.
  • Current profile.
  • Up to 30m.
  • 2 to 40 cells.
  • Wave Data.
  • Pressure & Acoustic Surface Tracking (AST) modes.
  • 2Hz sampling (max).
  • 512, 1024 or 2048 samples per burst.


GEMMS installs meteorological recording stations to measure a range of parameters including wind speed, wind direction, atmospheric pressure and atmospheric temperature. Installations can be self-recording or transmit data in real-time via the internet.


GEMMS designed the GEMMS_POD to house the complete instrument set (ADCP, acoustic modem, batteries) for real-time ocean monitoring in a water tight environment. This installation provides an easy, safe and efficient system for deployment and retrieval of real-time instruments.


The GEMMS surface drifters are designed to drift with the surface ocean currents and transmit positions back to the internet via satellite. The 60cm “sail” locks the drifter into the movement of the top 1 metre of the water column and the small floats provide stability. There is minimal windage associated with the drifter and so it records an accurate drift track driven by surface ocean currents.