Application of ADCP to Ocean Current Measurement in the Port of Lisbon

1. Where is Lisbon Port

Lisbon Port is located in the capital city of Portugal, which bears the name Lisbon. The port is a significant seaport and dates back to historical times.

Port Scale and Throughput

This port is of large scale and is considered an important hub in the country for internal and international trade. It has a high throughput, with cargo items ranging from containers to bulk cargo like grains and ores to liquid cargo like petroleum products and chemicals. The infrastructure of the port is such that it can handle big vessels, while it readjusts its capacity to manage the growth in the volume of trade continuously. It plays an important role in the economy of Portugal and acts as an entrance and exit for goods imported or exported.

Routes and Business

Lisbon Port is well connected to almost all the ports in the world. It has an extensive domestic and international shipping route. Domestically, it acts as a central distributor for various parts of Portugal. Internationally, it has trade relationships with countries from Europe, Africa, the Americas, and Asia. Major business activities include cargo loading and unloading, storage in mega warehouses and terminals, and value-added services like packing, sorting, and customs clearing. The port impacts other industries, such as tourism, as it is a common destination for cruise ships.

Management and Operation of the Port

The port is managed by a professional team of port authorities. They ensure that the port functions well, vessel traffic flow is maintained, berthing schedules are kept, and the area within the port is safe and secure. The facilities at the ports, such as the berths, cranes, and storage areas, undergo regular maintenance and upgrading to enhance efficiency in order to meet international standards. It cooperates with several governmental and regulating bodies on various levels: customs, immigration, environmental protection among others.

Facilities

Lisbon Port possesses modern berths in service - vessels of any size starting with small fishing boats to container carriers, huge supertankers receive appropriate receipt. Extensive warehouses, well equipped with inventory management facilities for storing and looking after the cargo in large scale. Cranes, forklifts, and conveyor belts are installed to speed up the handling process of the equipment for loading and unloading. Besides, facilities of refueling ships, fresh water, and ship repair are also available. There are also specific terminals for specific cargo, such as container terminal, liquid bulk terminal, and cruise terminal.

Channel and Direct Shipping

It has a well-maintained and dredged channel to ensure safe entry and exit of ships. The depth and width of the channel are large enough for big vessels. It provides direct shipping links to most of the major ports in the world, thereby reducing time and transportation cost and facilitating international trade.

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

Ensuring Safe Navigation

Ocean currents are of utmost importance regarding the safety of ships in Lisbon Port. Knowledge of the direction and speed of the current is of great importance to the pilots during the berthing and departure of ships. In such a busy port as Lisbon, where the traffic is considerable, current data of good quality may avoid collisions with port structures or other vessels. This becomes very important in adverse weather conditions or when dealing with large cargo ships with low maneuverability.

Ocean Current Information to Optimize Port Operations

This information helps in optimizing the processes of cargo loading and unloading. Various current states would, of course, provide a variation in time and stability for such operations. For instance, strong currents might need modifications in the positioning of the ship or the use of additional mooring equipment for safe working and integrity of the cargo transferred. Accurate current measurements allow port operators to better plan such operations, thus minimizing delays and enhancing productivity.

Planning of Port Infrastructure

Understanding ocean currents is very important in the long-term development and expansion of the port. The hydrodynamic forces exerted by the currents can affect the durability and stability of the port structures at the berths and piers. This information is important for engineers in designing and constructing new infrastructure that can stand up to the perpetual action of the currents. It also helps identify the best places for future expansions and improvements to minimize the negative impact of the water flow.

The ADCP therefore presents a more advanced and convenient way of ocean current measurement than the traditionally used methods. It can rapidly and accurately provide current details at varied depths with real-time data that is essential to the efficient operation and further development of the Lisbon Port.

3. How do ADCPs using the principle of the Doppler work?

ADCPs work on the principle of the Doppler effect. They send acoustic signals into the water. These acoustic waves scatter off the suspended particles or other objects in the water that are moving with the ocean current. When the waves are reflected back to the ADCP, the frequency of the reflected waves changes due to the Doppler effect.

By analyzing the frequency shift, the ADCP can determine the velocity of the ocean current at various levels.

ADCP in Port Ocean Current Measurement: Shipborne ADCP

Shipborne ADCPs are installed on ships operating in and around Lisbon Port. The ADCP, while the ship sails over the area of the port, continuously emits acoustic signals in different directions. It can measure the ocean current at several points along the path followed by the ship, hence giving quite a complete view of the current distribution in the area covered by the ship movement.

Fixed ADCP

Fixed ADCPs are normally installed at a fixed location within the port, say on the seabed next to critical infrastructure or at some strategic point along the waterway. This will provide information on ocean current conditions at that given location over a long period. This gives good data on regular patterns of the current and its effects on port facilities at that particular fixed point.

4. What is necessary for a high-quality measurement of Lisbon currents?

Material Reliability

To perform a high-quality measurement of the ocean currents in Lisbon Port, the equipment will have to be made from materials that are reliable. Considering the harsh marine environment involving saltwater corrosion, a variation of water pressure in different levels of depth, and the constant action of waves, the materials must be able to withstand such challenges without deteriorating the performance of the measuring device. The casing of ADCPs could be made from titanium alloy. High mechanical properties; this would be enough to oppose any of the mechanical forces on-site. Furthermore, very good corrosion resistance will surely promote its lifetime in seawater.

Size, Weight, and Power Consumption

The equipment must also be compact in size, lightweight, and with low power consumption. Compact size makes it easier to install at various places of the port whether on ships or fixed locations, light weight makes it easier to handle and deploy while low power consumption ensures that the equipment can run continuously without requiring frequent battery replacements or excessive power supply.

Cost-Effectiveness

Cost-effectiveness is important for large - scale measurement. The equipment cost should be reasonable so as to deploy it in batches in the port and collect the full range of current data.

5. Selection of Current Measurement Equipment

Usage Purpose

• Shipborne ADCP: This should be applied when the objective is to make mobile measurements while the ship navigates in the port area in order to get a wide overview of the situation at different parts of the port as quickly as possible. In this way, it would be possible to cover a wide range of areas during the movement of the ship.
• Bottom-mounted ADCP: For conditions that require long-term and continuous monitoring of the ocean current at a specific fixed location in the port, like near important facilities or areas where the impact of currents on structures is required to be closely monitored, bottom-mounted ADCP would be more fitting. It gives stable and consistent data at a fixed position.
• Buoy-mounted ADCP: In cases where it is not convenient to install fixed equipment on the seabed or on other structures, buoy-mounted ADCP can be used. The buoy-mounted ADCP can measure the ocean current in the upper layers of the water body and transmit the data wirelessly.

According to Different Frequencies

• Generally, in water with a depth within 70 m in Lisbon Port, 600 kHz ADCP is preferred because it gives high accuracy concerning current data at this water depth.
• For shallow water with depths around 110 m, 300 kHz ADCP is comparatively more suitable because it helps in capturing the current characteristics efficiently at this depth.
• The ADCP of 75kHz shall be selected for deeper water areas, with a water depth up to 1000m, as it can give deeper penetration and 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.