Application of ADCP to Ocean Current Measurement in Leixoes Port

1. Where is Leixoes Port?

Leixoes Port is situated in the city of Matosinhos, near Porto, in Portugal.

Port Scale and Throughput

It is a big port with large scale. The port boasts of high throughput, dealing in a wide range of cargo such as containers, bulk cargo grains, ores, and coal, and liquid goods such as oil and chemical products. It is a very important link in international trade, with a capacity to handle vessels ranging from medium-sized container ships to large bulk carriers. Over the years, infrastructure development and expansion have been continuously pursued in order to meet the demands of the ever-growing shipping industry.

Routes and Business

Leixoes Port is well-connected with most of the ports across the globe. It has an extensive domestic and international shipping network. In the domestic arena, it plays a very important role in the movement of goods within Portugal, providing good means of transporting products to and from the different regions of the country. Internationally, it is involved in trade with countries from Europe, Africa, and the Americas. Main activities comprise loading and unloading cargo, storage in well-equipped warehouses, and value addition, such as packaging, quality control, and customs clearance. It is also significant to the local economy because it supports the industries related to fishing and services relating to ships.

Port Management and Operation

The port is managed by professional port authorities who ensure the smooth functioning of the port. They are responsible for vessel traffic control, berthing, and departure schedules. In addition, they have to ensure safety and security in the port area, including periodic safety inspections and enforcement of security protocols. Maintenance and upgrading of the port facilities like berths, cranes, and storage areas are done periodically with the view to optimize the performance to meet international standards.

Facilities of Ports

Modern berths at the Leixoes Port, allow reception of vessels with distinct characteristics. Extensive areas of warehousing with state-of-the-art storage and handling mechanisms are developed to safeguard and control the goods. The cargo handling process is accelerated by installing the equipment for loading/unloading such as cranes, forklifts, and conveyor belts. Refueling facilities for the ships, freshwater supply, and ship repair facilities are also developed. Along with this, a container terminal and a liquid bulk terminal may be maintained in addition within the port.

Channel and Direct Shipping

It has a well-maintained channel, dredged in order to allow safe access and departure of ships. In this way, the channel is wide and deep enough for big ships. Thus, this means direct shipping links to other major ports around the globe; this reduces time and cost of transport and therefore allows an increase in international trade.

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

Importance for Ship Navigation

The measurement of ocean currents bears great importance in regard to the safety and efficiency of ship navigation in Leixoes Port. The ship pilots utilize the knowledge of the current direction and speed during berthing and departure. Current data can also help avoid collisions with port structures or other vessels, especially within busy ports such as Leixoes with numerous ships entering and leaving the facility. This is very important during adverse weather conditions or when handling large-scale cargo ships that have limited maneuverability.

Other key areas would be the knowledge of ocean currents, which is extremely useful in cargo handling operations efficiently. All of these current conditions contribute variably to the time and stability that this process would need. For example, heavy currents might require readjustments in the positioning of the ship or the extra usage of mooring equipment to ensure the safety of personnel and the integrity of cargo transferred. With proper current measurements, port operators can plan such operations more effectively and minimize delays, adding to overall productivity.

Role in Port Infrastructure Planning

In the long-term development and expansion of the port, knowledge of the ocean currents is quite important. The hydrodynamic forces of the currents can influence the durability and stability of the port structures at the berths and piers. This information is important for engineers in the design and construction of new infrastructure that can resist the continuous action of the currents, and it helps in establishing the best locations for future expansion and improvement to minimize the detrimental effects of the water flow.

The Acoustic Doppler Current Profiler (ADCP) provides much more sophisticated and easier methods of measurement than the currently used methods. It allows for rapid acquisition of detailed current data throughout the water column with accuracy, while the real - time data is crucial to the effective functioning and future enhancement of Leixoes Port.

3. Principle of the Doppler Works

ADCPs are based on the principle of the Doppler effect. They send acoustic signals into the water. These acoustic waves scatter against suspended particles or any other objects in the water that are moving with the ocean current. If the waves are reflected back to the ADCP meter, the frequency of the reflected waves shifts due to the Doppler effect.

Analysis of this frequency shift enables the ADCP current meter to calculate the velocity of the ocean current at discrete depth intervals.

ADCP in Port Ocean Current Measurement

Shipborne ADCP

Shipborne ADCPs are installed on ships that work around and within Leixoes Port. The ship travels around the port area, while the ADCP current profiler continuously sends out acoustic signals in different directions. It can measure the ocean current at many points along the path the ship travels, providing a comprehensive view of the current distribution in the area covered by the ship's movement.

Fixed ADCP

Fixed ADCPs are generally deployed at one place in the port-for instance, on the seafloor near an installation of particular importance or at some selected site within the channel. They monitor with time the ocean current conditions at that location, without change. In other words, their monitoring has provided very useful information on the regular patterns of the current and its consequences at that fixed point in time.

4. What is needed for high-quality measurement of the currents in Leixoes port?

Material Reliability

Reliable materials in equipment will be required to ensure that the measurement of ocean currents in Leixoes Port is done with high quality. Those materials should be resistant to the marine environment, including saltwater corrosion, different water pressures at different depths, and continuous wave action without deterioration in performance of the measuring device. For this purpose, the casing of ADCPs can be made from titanium alloy. It possesses high strength, to resist mechanical forces linked to the marine environment, and very good corrosion resistance that can give the material a service life in seawater.

Size, Weight, and Power Consumption

The equipment should also have compact size with low power consumption and minimum weight. Compact size gadget provides ease in installation in different areas of the port, onboard of ships, or at fixed locations. Lighter weight ensures manipulative practices in handling and deploying them. Low power consumptions promise continuity of the equipment's work without frequently changing the batteries or high voltage power supply.

Cost-Effectiveness

The cost-effectiveness for large-scale measurement is very important. The equipment cost should be reasonable and can be widely used in the port to get comprehensive current data.

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

The usage purpose determines the choice of equipment.

• Shipborne ADCP: It is meant to be useful for mobile measurements while the vessel cruises in the port area. One wants to get a general and wide overview of the given situation in various parts of the port as fast as possible. Wide areas could be covered by movement in the ship.
• Bottom-mounted ADCP: when there is a need to monitor the ocean current at some fixed location in the port continuously and for long periods, such as near important facilities or places where the influence of currents on structures needs close monitoring, a bottom-mounted ADCP will be appropriate. It provides stable, consistent data at a fixed position.
• Buoy-mounted ADCP: In locations where the installation of fixed equipment on the seabed or other structures is not convenient, the buoy-mounted ADCP may be used. The buoy-mounted ADCP can measure the ocean current in the upper layers of the water body and transmit wirelessly.

Based on Different Frequencies

• At the water depths within 70m, 600kHz ADCP is normally chosen for current measurement with this range.
• For approximately 110 m of depth, it's better to use the 300 kHz ADCP. This will most probably fit for the depiction of characteristics. The -75kHz ADCP is better for deeper water areas, reaching to a water depth of 1000m, as it can penetrate deeper into the water to obtain reliable current information.

There are well-known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, a Chinese ADCP brand, China Sonar PandaADCP, is also worth considering. It is made of all - titanium alloy materials 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.