ADCP's Application to Ocean Current Measurement in the Port of Paldiski

1. Where is the Port of Paldiski?

The Port of Paldiski is in Paldiski, Estonia. It is one of the major ports on the coast of the Baltic Sea.

Port Scale and Throughput

The port is of a decent scale and able to handle a variety of cargo. Its throughput includes industrial raw materials, fuel, and construction materials. It also serves as a port for fishing vessels and smaller commercial ships. It is an important facility in regional trade, as it enables the transportation of goods from and to Estonia by other Baltic countries and other European destinations.

Routes and Business

Paldiski port has connections with several shipping routes. In the domestic sense, it connects with other Estonian ports mainly for the dispersal of cargo. Internationally, it connects with the Baltic Sea trade enclave, allowing trade exchange with countries like Finland, Sweden, and Germany. These business activities include general cargo handling, supporting fishing operations, and at times the movement of specialized cargo. The port also offers ancillary services like ship repair and maintenance to a limited extent.

Port Management and Operation

The port is directed by a team of professionals who ensure efficient running of the port; they are in charge of berthing and un-berthing of ships, ensure trouble-free cargo handling, dovetailing with stevedoring companies and other services, and maintain security/safety. Customs and other regulatory agencies also operate at the port as part of their role in ascertaining that all things are in order with traded goods and safety concerns.

Port Facilities

It has various facilities: individual berths, from where small and big fishing vessels to medium-sized cargo ships berth; the cargo-handling facilities include cranes and forklifts for the loading and unloading of goods; warehouses or storage areas allow for temporary storage of cargo; there are fuel oil storage with a dispensing facility for ships; besides, it has a small-scale ship repair yard.

Channel and Direct Navigation

The port has a well-maintained channel that allows ships to enter and leave safely. The channel is dredged from time to time to give the right depth for vessels with different drafts. For navigation, buoys, lighthouses, and modern radar systems guide the ships while approaching and leaving the port; thus, it allows the direct navigation of ships from different directions.

2. Why is it necessary to measure the ocean currents in the Port of Paldiski?

Navigation Safety

Measuring ocean currents in the Port of Paldiski is important for ship safety. Knowledge of current patterns enables captains and navigators to plan routes and maneuvers better. Strong or unpredictable currents may lead to accidents like collisions with other vessels or running aground. By having accurate current data, ships can adjust their speed and course to avoid such risks.

Port Operational Efficiency

Also good to say is that it is beneficial towards the port's efficient management. Understanding the ocean current assists in better scheduling of arrivals and departures of ships at its ports. Ships can save much fuel during docking and undocking while the wind force may be favorable, this could be cost-effective; the port resources are bound to be utilized more wisely. For instance, if the current is in the direction of a berth, a vessel can take full advantage in its approach.

Environmental Considerations

From an environmental point of view, the present measurements are relevant. Currents can affect how such pollutants as oil slicks or wastewater discharges will disperse. In the case of an accident or in a routine discharge, effective containment and clean-up depend on knowing the current pattern. This minimizes harm to the marine environment and the surrounding shores.

Infrastructure Maintenance

Current data is highly relevant for long-term planning and maintenance of port infrastructure such as breakwaters and quay walls. These structures may get damaged due to the force exerted by ocean currents over time. Acoustic Doppler Current Profiler (ADCP) has a more advanced and convenient way of measuring the currents in the ocean than those traditional methods; it offers detailed, real-time information about current profiles at different depths.

3. How Do ADCPs Based On the Doppler Principle Work?

The principle on which ADCPs operate is the Doppler principle. It sends acoustic signals into the water. As these acoustic waves encounter moving particles in the water-sediment particles, plankton, or any other small organisms carried by the ocean current-the frequency of the reflected waves changes. This change in frequency, otherwise known as the Doppler shift, is directly related to the velocity of the moving particles and thus the velocity of the ocean current.

Commonly, ADCPs have multiple transducers, which emit and receive these acoustic signals in multiple directions. By measuring the Doppler shift from multiple directions-commonly in a three - dimensional or two - dimensional configuration-the ADCP current meter will be able to calculate both speed and direction of the ocean current at different depths.

ADCP in Port Ocean Current Measurement: Shipborne ADCP

Shipborne ADCPs are installed on vessels. The ADCP flow meter continuously sends acoustic signals downward and around as the ship moves through the water, collecting data on the current velocity as the ship crosses over various areas of the port. Its advantage is in its mobility, allowing for measurements in a wide range of locations within the port waters. However, it is necessary to account for the ship's own motion to obtain accurate results. Any such errors due to the ship's movement are compensated and calibrated using a set of calibration and compensation techniques.

Fixed ADCP

Fixed ADCPs are deployed at fixed locations in the port, like on the seabed or on fixed installations such as piers and buoys. They keep monitoring one fixed point in the ocean current continuously for an extensive time. This provides long-term and consistent data to understand the regular current patterns in a specific area of the port. The disadvantage is that they only cover a very limited area around their installation location, but they are very useful in establishing reference current data for particular regions within the port.

4. What's needed for high-quality measurement of Paldiski Port currents?

Durable Materials

Reliable material of equipment - this is a must for high-quality measurement of the ocean currents in the Port of Paldiski. Due to hardships in the marine environment, including the corrosive influence of seawater and possible impacts from floating debris, a durable material is critically required.

Compact and Lightweight Design

The size of the equipment should be small to facilitate easy installation, especially in areas with limited space such as on small buoys or in regions with complex underwater structures. A lightweight design is also beneficial as it simplifies the installation and maintenance processes.

Low Power Consumption

Low power consumption is especially relevant for long-term monitoring. Equipment that requires high power may have difficulty operating continuously because of limited power supply options in the port area or the frequent replacement of batteries.

Cost-Effectiveness

The cost-effectiveness is also another factor. For current measurement in the port in detail, cheaper equipment enables the deployment in higher numbers to develop a fine understanding of the current conditions within the port waters.

The casing is preferably made from titanium alloy. This guarantees a very long life because of its excellent corrosion resistivity in seawater. Compared to other materials, the alloy is relatively strong enough and light, thus giving the instrument the ability to withstand high pressures at larger depths without overloading it with much weight. Its biocompatibility offers the least adverse effects in the marine environment and minimal interaction with the acoustic signals involved in the ADCP profiler.

5. How to Choose the right equipment for current measurement?

Based on Usage Purpose

• Shipborne ADCP: If the intention is to obtain current data over a wide area of the port while the ship is in operation-for example, during regular port surveys or when collecting data for navigational chart updates-shipborne ADCPs would be a good choice. They can cover different parts of the port as the ship moves around.
• Bottom-mounted (Sitting) ADCP: When the purpose of measurement is long-term and fixed-point monitoring at points in the port-like, near critical infrastructure such as breakwaters or at the entrance of the port channel, then bottom-mounted ADCPs can be used. It ensures very stable and continuous data for the understanding of local current characteristics.
• Buoy-mounted ADCP: For areas where it is not convenient to install fixed equipment on the seabed or on structures, or when a floating monitoring point is needed to capture surface and near-surface current conditions, buoy-mounted ADCPs are the way to go.

Based on Different Frequencies

• For water depths up to 70m, the 600kHz ADCP would be quite appropriate. It provides high-resolution current profiles in relatively shallow areas, hence quite suitable for those parts of the port that have shallow water, such as nearshore or in small bays.
• For water depths up to 110m, the 300kHz ADCP is more appropriate since it will be able to measure the current velocities quite effectively at these water depths.
• In deeper areas, like the approach to the port where water depth may be over 1000m, it is recommended to use a 75kHz ADCP. Its lower frequency allows it to reach greater depths and still obtain useful current information.

There are well-known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, for a cost-effective option, the China Sonar PandaADCP is worth considering. It's made of all-titanium alloy material and offers an excellent cost - performance ratio. You can learn more about it at (https://china-sonar.com/).

Here is a table with some well known ADCP instrument brands and models.