ADCP Applied to Ocean Current Measurement in Ponta Delgada Port

1. Where is the Port of Ponta Delgada?

It is located in the Azores, an Atlantic Ocean archipelago, and belongs to Portugal; the Port of Ponta Delgada is an important facility within the region.

Scale of the Port and the Cargo Throughput

The port is of relatively big size, with quite well-developed infrastructure to handle almost any type of vessel. Its annual throughput covers everything from agricultural products originating in the Azores to industrial supplies and consumer goods. It is an important link in the exportation of local produce-such as dairy, fruits, and handicrafts-and the importation of basic supplies for the local population and industries.

Routes and Business

The Ponta Delgada Port has links with other Azores, mainland Portuguese ports, and some international destinations. The nature of business of this port is multifunctional. This port is an important base to the fishing industry, as the fishing vessels call in for unloading and taking supplies. Tourist sectors also benefit from it because cruise ships visit with quite a number of tourists regularly. In addition, it provides a means of transport of merchandise between the several islands of the Azores and with the outside world.

Port Management and Operation

The port is run by a professional team that aims at smooth operations. All the facilities are in good order and include modern berths with advanced machinery for loading and unloading. There are storage areas with different zones for perishable goods like food products, all kept at different temperatures. Similarly, it has a well-developed communication and navigation system that assists in safely arriving and departing of ships.

Port Facilities and Waterway

The port facilities are designed in such a way that they can handle the needs of different vessels. This includes refueling, ship repair, and waste disposal. The water leading up to the port is consistently made in a highly professional manner in order to provide comfortable and smooth passage to ships of different sizes. It has direct access to the open sea, which is its integral contribution to being a hub of trading and transportation.

2. Why is measurement of currents necessary in Ponta Delgada?

Improved Safety of Navigation

Measurement of currents in Ponta Delgada is vital for ensuring the safety of navigation. This port is subject to quite heavy shipping traffic-from small fishing boats to large cargo vessels and even cruise ships. In fact, ocean currents may have a greater impact on the movement of these vessels. For example, at the mouth of a port, strong and variable currents can cause ships to veer off course and thus increase their likelihood of collision with other vessels or piers, or running aground. Accurate information on current speed and direction allows captains of ships to more effectively plan arrival and departure by course and speed changes that will assure safe passage.

Optimization of Port Operations

Knowledge of ocean currents aids in some aspects of the optimization of port operations. The flow of currents can affect the time and efficiency of ship berthing and unberthing. For example, if the current direction is favorable, it can facilitate docking, hence reducing excessive tugboat assistance, which saves time and resources. Understanding the pattern of the current also assists in planning the loading and unloading of cargo. In the case of the fishing industry, knowledge about ocean currents guides fishermen to better productivity as currents can transport nutrients and therefore fish.

Infrastructure Planning and Maintenance

For the long-term planning and maintenance of the port infrastructure, there is a need for current measurement. Currents can influence sedimentation patterns around the port. By observing the ocean currents, it helps port authorities make informed decisions in dredging the area for the required depth of the waterway and stability of the berths. It also serves the long-range planning for future expansions or enhancements that will involve new berth construction or facilities relocation, depending on one's understanding of current effects on the seabed and general port environment.

These current meters allow a much more advanced and efficient method of measuring currents compared to traditional methods. It does this by allowing real - time and accurate data that is so important for smooth functioning and management of the Port of Ponta Delgada.

3. How do ADCPs using the Doppler principle work?

The principle of operation for ADCPs is based on the Doppler effect. They send acoustic signals into the water. These acoustic waves scatter off moving particles in the water, such as suspended sediments, plankton, or small organisms. When the particles are in motion, due to the Doppler effect, the frequency of the reflected acoustic waves changes.

This frequency shift is measured by the ADCP profiler and converted for the velocity of the moving particles. The movement of the particles is related to the ocean current, and hence the ADCP current meter calculates the speed and direction of the ocean current.

Ship-borne ADCP in Ponta Delgada Port

When an ADCP current profiler is used in a port, it is fixed on a vessel. While this ship travels across the port waters, the ADCP flow meter sends acoustic signals downwards and sideways. During the movement of the ship, it will be continuously collecting information on ocean currents with variable depths and positions. By this, the current scenario over a vast area of the port can be comprehensively understood.

Fixed ADCP at Ponta Delgada Port

Usually, a fixed ADCP is installed in a specific place in a port, on a pier, or some submerged structure. It keeps monitoring the ocean currents that pass through its position. Fixed ADCPs provide long-term stable data of currents in a particular area in the port, which is used to analyze the pattern and changes of the currents regarding regularity in that very location.

4. What is necessary to obtain high-quality measurements of the currents at Ponta Delgada Port?

Material Reliability

The equipment should provide high material reliability for high-quality current measurement in Ponta Delgada Port. The environment of the port is harsh; thus, the equipment will be exposed to seawater, which is corrosive and mechanical impacts. Hence, the equipment should be constructed from durable materials to enable such conditions and ensure a long-term and accurate measurement process.

Small Size, Light Weight, and Low Power Consumption

Other desirable features include small size, light weight, and low power consumption. A small-sized ADCP is easily mounted at any location within the port, whether it is on ships or fixed structures. The light-weight device simplifies transportation and installation processes, reducing labor and costs. As the power consumption is low, this equipment can serve for quite a long time without replacement of batteries or high energy consumptions, which is highly essential for the measurement of current over a long period and without intermission.

Cost-effectiveness

Another important factor is that it has to be cost-effective. In order to carry out large-scale measurement of ocean currents in the port, the cost of the equipment should be reasonable. The ADCP meter housing should be made of Titanium alloy. The main benefits of using this material in the instrument are threefold: it has the best strength-to-weight ratio, capable of withstanding underwater pressures and mechanical forces from machinery; second, it offers good corrosion resistance for long-term use in seawater without deterioration of the equipment. Besides, compared with other materials, the relatively light weight will be more suitable for installation in the port.

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

Based on Usage Purpose

According to the specific purpose of the use, equipment for the measurement of currents would vary. In this case, if the measurements are supposed to be mobile while the ship is navigating in the port, then the ship-borne ADCP will be suitable as this will cover all the areas of the port according to the movement of the ship and thus give an overview of the current situation in all the areas of the port.

The sit-on-bottom ADCP will serve better for long-term fixed-point monitoring in a particular area of the port, while it stays at one position and continuously records the current conditions, which is of great value when analyzing the local current patterns.

With more demand to monitor the broader area on the water surface with some mobility, this buoy-mounted ADCP is considered.

Based on Water Depth

In addition, varied frequencies of ADCPs must be selected according to varied water depth. The frequency of 600kHz works well for water depth up to 70m since it will resolve current profiles in shallow water with higher accuracy. As for water depth about 110m, the ADCP-300kHz is much proper. For waters with deeper features up to 1000m, the ADCP-75kHz would then be recommended to assure dependability in the current result.

There are well-known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, a Chinese ADCP brand-China Sonar PandaADCP is also worth mentioning. It is made of all - titanium alloy material, combining excellent durability and corrosion resistance with an incredible cost - performance ratio. You can find more information about it on its website: (https://china-sonar.com/).

In general, ADCP is responsible for the measurement of currents in Ponta Delgada Port, so proper selection of equipment based on needs is the first crucial point for efficient port operation and management.

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