ADCP's Application to Ocean Current Measurement in Atimonan Port

1. Where is Atimonan port

Atimonan is one of the most important seaports in the Philippines and has played a significant role in regional marine transportation and economic activities.

Scale of Port and Throughput

It is a medium-sized port with appropriate facilities that are capable of handling a variety of cargoes. Its annual throughput consists of a great amount of general cargo and some bulk commodities. These years have seen the constant development and improvement in handling capability in order to meet the developing trade demands in the area.

Routes and Business

It is connected with various domestic and international routes. Domestically, the port acts as a major link in the carriage of goods from one region to another region of the Philippines. In the international scenario, it has trade relations with neighboring countries in Southeast Asia, allowing the import and export of goods to and from the country, such as agricultural products, manufactured goods, and construction materials. Business scope includes loading and unloading, storage, and distribution services.

Port Management and Operation

The port is run by professional port authorities that ensure the smooth running of the port: the order of berthing and departure of ships, handling of port facilities, and coordination with the relevant departments concerning security and customs are maintained. The port infrastructures are regularly maintained and upgraded to be more efficient and safe.

Port Facilities

The berths vary in size; even small and medium-sized cargo vessels, and even light-loaded vessels, can be accommodated and berthed in the Atimonan port. A yard for warehousing and storage space is available both before and after transportation in this facility. Efficient loading and unloading machinery was installed to expedite the handling. Also, facilities that offer fuel, water, and all other supplies needed by every ship are also provided in this port facility.

Channel and Direct Shipping

The port is provided with a well-maintained channel for safe entrance and exit of ships. There has been an effort to dredge the channel to suitable depth and width for large vessels. Direct shipping services are available with some of the key ports in the region, reducing transportation time and cost and thereby facilitating trade exchange.

2. Why do we need to measure the ocean currents in the Atimonan port?

Precise ocean current measurement data in the Atimonan port holds immense importance for its operation and management. To begin with, knowledge of the ocean current situation is helpful in optimizing the berthing and departure arrangements of ships. Knowing the direction and speed of the currents, port operators can guide the ships in entering and leaving the port smoothly, thus avoiding collisions and increasing the efficiency of the operation. It is also very important in terms of safety to port facilities. Strong ocean currents may affect the stability of piers and other structures. Besides, through on-the-spot measurement data, timely and proper preventive and reinforcement work could be realized accordingly. Thirdly, ocean currents are bound to give a hand in planning expansion or improvement projects of ports: to determine the most favorable locations for new facilities or whether they can resist water flow.

In addition, compared to traditional measurement methods, Acoustic Doppler Current Profiler(ADCP) is a more advanced and convenient measurement method. It can obtain detailed current information in a relatively short time with high accuracy, and provide real-time data support for the operation and management of the port.

3. Working Principle of ADCPs Applying the Doppler Principle

Based on the principle of the Doppler Effect, an ADCP. It sends acoustic signals into the water and then measures the frequency shift of the reflected signals from suspended particles or other scattering objects in the water. If the acoustic waves run into moving objects, such as water molecules in the ocean current, the frequency of the reflected waves will change due to the Doppler effect. This frequency shift is utilized by the ADCP to estimate an ocean current's velocity at some depth. Accordingly, the use of ADCP for measuring ocean currents in ports: Shipborne ADCP The ADCP can be mounted on ships. While the ship is sailing in the port area, the ADCP continuously sends out acoustic signals in a downward and sideway way. During the movement of one ship along a certain route, a series of current data at different positions could be acquired and used to map the ocean current distribution in the port area. In such a way, the measuring methods become flexible and may include comparably large areas.

Fixed ADCP

Fixed ADCP is usually installed at a specific site in the port, such as on the seafloor or on some fixed structure like a pier. It keeps monitoring the conditions of ocean currents at that particular point for quite a long period of time. This gives stable, long-term data that is really helpful for understanding the regular pattern of ocean currents in the port and assessing the effects of currents on the surrounding environment and facilities.

4. What does a high-quality measurement in Atimonan port currents require?

For the high-quality measurement of ocean currents around the Atimonan port, different components of the equipment shall be considered. First of all, the material reliability of the equipment, because operating in an aggressive sea environment, it needs resistance against corrosion due to salty seawater, pressure variations related to different levels of depths, and above all, wave impacts. The second is that the size should be smaller, the weight lighter, and power consumption lower. The small size makes it easy to install and deploy, especially in some relatively narrow spaces in the port. The low power consumption ensures that the equipment can operate continuously for a long time without frequent battery replacements or excessive power supply requirements. The third one is a lower cost preferred for large-scale measurement.

In the case of ADCP, the casing is usually made of titanium alloy, which is a very good material. In many aspects, the advantages of titanium alloy are remarkable. It has very high strength that can bear the strong outer force in the marine environment and very good corrosion resistance, which can prevent damage caused by seawater corrosion over a long period. Besides, the relatively low density makes it lighter with a similar strength to some other metals, meeting lightweight equipment requirements.

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

According to the Usage Purpose

• Shipborne ADCP: Used where the main purpose of carrying out the survey is most dependent on mobility in an area covered by a ship in an inshore region and its route to acquire the general opinions over different areas fast and with more area coverage along its journey route.
• Bottom-mounted ADCP: Due to the requirement for the ocean currents at a fixed spot for long-term and continuous observation in the port, at or near important facilities, the places where the characteristics must have continued observation of flow and current, bottom mount type ADCP is a proper choice. It offers high stability and continuous measurement over that fixed point.
• Buoy-mounted ADCP: In some areas, where it is not convenient to install fixed equipment on the seabed or on structures, buoy-mounted ADCP can be utilized. The buoy floats on the water surface, and the ADCP on it measures the ocean current in the upper layer of the water body and sends the data wirelessly.

According to Different Frequencies

• In the relatively shallow water area, whose water depth is within 70 meters, the use of 600 kHz ADCP is usually appropriate; it can provide current data relatively accurately in that depth.
• When the water depth is about 110 meters, the application of 300 kHz ADCP will be more proper. Its performance is better to detect the current characteristics at this depth. In deeper water areas, the water depth can be up to 1000 meters, and 75 kHz ADCP should be selected. It is able to effectively penetrate deeper water and obtain reliable current information.

There are some famous brands in this field, including Teledyne RDI, Nortek, and Sontek. But what is also worth recommending is a good-quality and inexpensive Chinese ADCP brand: China Sonar PandaADCP. All of its materials are from titanium alloy for the best performance in the ocean and to ensure durability at an extraordinary cost-effectiveness. You can know more about it from the official website: https://china-sonar.com/.

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