ADCP in Agioi Theodoroi Port: Ocean Current Measurement

1. Where is Agioi Theodoroi Port?

Overview of Agioi Theodoroi Port

Agioi Theodoroi Port is located in Greece. It is a port with a moderate scale and throughput. The port plays an important role in the local and regional maritime activities, serving both commercial and fishing vessels. It is involved in the transportation of a variety of goods such as agricultural products, building materials, and some light industrial goods.

The port is well-connected to the surrounding areas through a network of roads, facilitating the distribution of goods to inland destinations. The management of the port focuses on maintaining efficient operations, including vessel traffic control, cargo handling, and ensuring the safety of the port area.

Port Facilities

Berths: The harbour has a number of berths and is suitably designed for handling various craft. Therein, it shall have berths for medium-sized cargo ships and berths for fishing boats. These berths shall be supported with mooring and docking facilities, which offer safety during arrival and departure. Bollards and fenders offer protection at the time of docking or undocking between the ships and the berth.

Cargo-handling Equipment: Along the quay, there is a range of cargo-handling equipment. For handling general cargo, there are forklifts and small cranes. For bulk materials such as sand and gravel, there are conveyor systems and grabs. In the case of fishing vessels, there are facilities for unloading fish and other marine products.

Storage Facilities: There are storage areas for different types of cargo. For agricultural products, there are warehouses with proper ventilation and temperature control to maintain product quality. For building materials, there are stockpiles with containment systems to prevent spillage. There are also cold-storage facilities for perishable goods.

Channel and Aids to Navigation: The channel in this port is dredged appropriately, together with its width, to make sure that ships pass through the port safely. This course offers various navigational aids such as buoys, beacons, and radar systems, which guide ships both while entering and leaving the port area. These radar systems further provide real-time information concerning the position and movements of other vessels in the environs of a given port.

2. Why should we measure the ocean currents in the Agioi Theodoroi Port?

Importance for Port Operation and Management

Measuring ocean currents in Agioi Theodoroi Port is of great importance. Firstly, because vessel navigation safety depends on the knowledge of current speed and direction, which every captain needs to know upon approach to the berths or when navigating through the channel. A strong cross-current near a berth involves a difficult and dangerous docking operation. For instance, the ships approaching a berth against a strong current have to make sure that their speed and angle of approach are changed accordingly in view of smooth and safe docking. Precise current measurements allow captains to make informed decisions in order to minimize the occurrence of collisions and other sorts of accidents.

Second, it is important for the optimization of port operations. Current data assists in the efficient scheduling of the arrival and departure of ships. With knowledge of tidal currents and other periodic flow patterns, the port administration can better plan berthing allocation and loading/unloading activities. This results in increased productivity since it enables better coordination of cargo-handling operations.

From an environmental perspective, in the event that pollutants like oil or chemicals spill accidentally, knowledge of ocean currents comes in handy. For a port that handles such cargo, it is important to forecast the spread of a spill. The current data can be used to immediately implement containment and mitigation measures in order to reduce environmental damage to a minimum.

Acoustic Doppler Current Profilers, on the other hand, are more advanced and much more convenient to measure these currents compared to the traditional methods.

3. How do ADCPs using the Doppler principle work?

Measurement Principle

Basically, ADCPs operate under the Doppler principle. If an ADCP current meter emits an acoustic signal into the water, this incident wave interacts with moving water particles. Because the water particles are moving due to an ocean current, they cause a frequency shift of the reflected acoustic signal that is received by the ADCP. Through the principle of the Doppler effect, the shift in frequency is proportional to the flow's velocity.

Speed and Direction Calculation From the magnitude and direction of this frequency shift, this instrument can compute the speed and direction of the ocean current at discrete points in the water column. Due to the sending of signals at several angles and at varied depths, it will be able to make a profile of the ocean current, with the variation of the current with depth.

Deployment of ADCP in the Port

Shipborne ADCP

One ADCP is installed on ships operating in the Agioi Theodoroi Port area. While the ship moves around the port area, the ADCP flow meter continuously sends acoustic signals into the water underneath. The movement of the ship enables the ADCP meter to cover a wide area for current data collection. For instance, a research or inspection ship with a shipborne ADCP could conduct a routine survey of the port and record current patterns over different areas of the port for a proper understanding of the water flow situation.

Fixed ADCP

Fixed ADCPs are deployed at specific, fixed locations in the port, such as on the seabed near important navigational areas or at the entrance/exit of the port. These ADCPs continuously monitor the ocean currents at their fixed positions over a long period. The data collected is useful for analyzing the regular current patterns in specific areas of the port. For instance, a fixed ADCP installed near the port entrance can record the incoming and outgoing currents, helping to understand the tidal effects and other consistent flow characteristics in that region.

4. What’s needed for high-quality measurement of Agioi Theodoroi port currents?

Equipment Requirements

Such high-quality measurements of the currents in Agioi Theodoroi port require specific equipment characteristics. First and most importantly is material reliability; the equipment has to endure the harsh marine environment. Seawater contains salts and other chemical substances that might destroy materials after some time. The equipment also needs to withstand pressure variation at different water depths and the mechanical forces imposed by waves and currents.

It should be of smaller size, lighter weight, and with low power consumption. The small size can easily fit in many installation locations in the port either on ships, fixed structures such as piers, or seabed. The light weight makes it easy to install and transport. Low power consumption ensures the equipment can work unattended for many hours without replacing batteries, or excessive power supplies, a feature that will be very relevant for long-term monitoring. Cost is another important consideration: Lower cost allows a greater number of measuring devices to be deployed by the port for much wider area current monitoring across the various areas of the port facility.

The Advantage of Titanium Alloy for ADCP Casing

Acoustic Doppler Current Profiler (ADCP) casings are best in titanium alloy. The resistance of titanium alloy to corrosion is quite good, and it sustains the structural integrity and functionality of the metal even in seawater for a long time. The high strength-to-weight ratio allows for a casing to be durable but of a relatively lightweight construction. Thus, higher pressures exist in deeper portions of the Agioi Theodoroi port, in which these situations can be effectively tackled and handled by an ADCP current profiler covered by casing using titanium alloy, in full view of the capability for delivering correct current measures accurately.

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

Selection Based on Usage

Shipborne ADCP: Where the objective is to conduct a wide-area survey of the port waters while the ship is in operation, then the shipborne ADCP will be applicable. It can cover different sections of the port as the ship moves around, collecting a large amount of data for an overall understanding of the current situation in the entire port area. It gives a useful insight into general flow patterns and the variability among the flow patterns throughout the various port water areas.

Sitting - bottom ADCP: The sitting-bottom ADCPs are more applicable for the long-term fixed-point monitoring of certain positions in the port, like near some important infrastructures or areas with a complex behavior of currents. They are able to continuously record current data at those fixed positions, therefore providing insights into the local current characteristics and their variations over time.

Buoy-mounted ADCP: In cases when it is not convenient to install fixed equipment on the seabed or on ships, buoy-mounted ADCPs can be used. They float on the water surface and are able to measure the currents in the upper layers of the water column. They are relatively easy to deploy and can be relocated if needed, hence suitable for monitoring certain dynamic or hard-to-reach areas within the port.

Selection Based on Frequency

The choice of frequency for ADCPs depends on the water depth in Agioi Theodoroi port. For areas with a water depth of up to 70 meters, an ADCP with a frequency of 600 kHz is usually a good choice as it can provide accurate current measurements in this relatively shallow depth range. Where the water is deeper, say up to about 110 meters, it is better to use an ADCP flow meter with a frequency of 300 kHz. For those really deep parts of the port with water up to 1000 meters, an ADCP with a frequency of 75 kHz would be best to ensure good profiling of the ocean currents at such great depth.

There are several well-known ADCP profiler brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, there is also an excellent Chinese ADCP brand-China Sonar PandaADCP. It is made entirely of titanium alloy material, which not only ensures its durability in the marine environment but also offers an excellent cost-performance ratio. For more information, you can visit its official website: (https://china-sonar.com/).

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