Global Positioning System (GPS) provides position and timing information continuously in various places on earth. Because the GPS can be accessed by an unlimited number of users, the GPS is a passive system. Therefore, the user can only receive satellite signals with the help of GPS receivers.
The use of GPS technology is helping job - survey work mapping, topography, hydrograph, geology, land surveying, and can also be used as a navigation aid fishing. In fact there are several types of GPS that is used for hobbies. Such as fishing, hiking, travelling, and sports.
Initially Acoustic System developed by the British in pre-World War II (WW II) by making ASDIC (Anti Sub-marine Detection Investigation Committee) which proved very useful for States Navy in World War II Allies.
After World War II ended, the more widespread use of acoustics for peaceful and scientific purposes, among others, used to; study the process of sound propagation in water media, research, and acoustic properties of objects contained in a water, communication and positioning in the column waters.
Furthermore, the rapid development of acoustics in the early decades of the ’70s because it has been found Echo Integrator which can produce absolute values for the prediction and estimation underwater.
Hydro-acoustic is a detection technology under the water by using acoustic devices (acoustic instruments), among others; Echo Sounder, FISHFINDER, SONAR and ADCP (Acoustic Doppler Current Profiler). This technology uses voice or sound to perform the detection.
As we know that the speed of sound in water is 1,500 m / sec, while the speed of sound in air is only 340 m / sec, so that this technology is very effective for detection under water.
Some basic steps are the detection of underwater transmitter that generates electricity with a certain frequency. Then distributed to the transducer which will convert electrical energy into sound, then sound is in the form of sound pulses emitted (usually with units ping).
The sound emitted will be about the object (target), then the sound will be reflected back by objects (in the form of echo) and received by the transducer device. Echo is converted back into electrical energy; then forwarded to the receiver and by a fairly complicated mechanism to occur processing by using the echo signal processor and echo integrators.
Processing is supported by other equipment, computers, GPS (Global Positioning System), Colour Printer, software programs and compass. The end result is data ready to be interpreted for various desired purposes.
When compared with other methods in terms of estimation or prediction, hydro-acoustic technology has advantages, among others. Information on the detected area can be obtained quickly (real time). And directly in the detection (in situ).
Another advantage is no need to rely on statistical data. And not harmful or damaging the object under study (friendly), because the detection performed remotely using the voice (underwater sound).
According to MacLennan and Simmonds (1992) which estimated the population are absolute values. Hydro-acoustic can be used in measuring and analyzing almost all contained in the water column and base, the application of this technology for various purposes among others, that mineral exploration, oil and seabed energy (seismic survey), detection of the location of the wreck (Shipwreck location ), estimates of marine life, measuring the rate of sedimentation processes (sedimentation velocity), measures the flow of water column (internal waves), measuring the flow speed (current speed), measure the water turbidity (turbidity) and the contours of the seabed (bottom contour).
Currently, hydro-acoustic has a very large role in marine and fisheries sector, one of which is in the estimation of fish resources (fish stock assessment). Hydro-acoustic technology with the echo sounder can provide detailed information about the abundance of fish, fish density distribution of fish, swimming depth position, size and fish length, orientation and speed of swimming fish and diurnal variation-nocturnal fish migration. Currently developing increasingly significant acoustic instruments, with the development of more advanced variants, namely Multibeam and omnidirectional. Echo sounder devices have a variety of types, namely single beam, dual beam
Hydro-acoustic method is an attempt to obtain information about an object under water by transmitting sound waves and to study the reflected echo. Fish used in detecting hidroakustik system that emits an acoustic signal vertically, usually called echo sounder or fish finder.
The use of hydro-acoustic method has several advantages, among others:
1. high speed.
2. direct estimation of fish stocks and the broader region and to monitor the movement of fish.
3. high accuracy.
4. not harmful and damaging fish resources and the environment, because the sound frequency used is not harmful for the user equipment or object being surveyed.
The use of this technology is very helpful in the search for new fish resources, so that will speed decision-making or policy, especially to establish fishing areas for potential fish can be maintained.
The integration of all the above methods can be done with the cooperation between the relevant parties. Images obtained through satellite remote sensing, for example analyzed in the Institute of Aviation and Space Agency (LAPAN) or in other relevant agencies. The resulting data is the basic information to determine potential areas of fish. Data and information can also be obtained through the results of acoustic surveys in the same waters for some time of observation, which is expected to yield more accurate information about the existence of which it has been catching fish. This information is then presented to the user, such as fishermen or fishing entrepreneurs in conducting fishing operations so that fishing vessels could stir into the area in question, and thus can reduce operating costs such ships
Countries that developed on marine-fisheries sector (Norway, Japan, the United States, China and Peru) depend on this acoustic technology. They used to explore resources quickly, so as to exploit optimally, efficiently and economically because of the cheap cost of exploration and exploration of a fairly brief time.
In addition to exploitation by more environmentally sound, sustainable and lasting, because it was unclear how many potential resources that will be in that exploitation, just need to choose what policies are most appropriate for continuous and sustainable management of these.
Until now, hydro-acoustic technology has not been widely used on marine-fisheries sector in Indonesia, particularly by fishing companies. We recommend these companies want to utilize this technology to the maximum exploration and optimal exploitation of resources.
Advanced equipment and supplies in the form of fish finder Global Positioning System (GPS) can actually be applied to fishermen in Indonesia because it can facilitate the fishermen know where the fish. The tool is possible to reduce the burden on fishermen from the increase of fuel oil (BBM) which is currently being felt. Aid equipment and GPS Fish finder provided this can save fuel. They just will sail to a place that there are hordes of fish in the sea so as to enhance the existing marine fish products. Fish finder used can also provide information on temperature, currents, chlorophyll and other fertility. While GPS will allow fishermen to know the coordinates of the existence of their boats while sailing. It was obvious that the role or fish finder and GPS applications in the search for fish presence information is very important and useful for fishermen.
Portable Versions
This is a gadget for the pro angler or newbie, sometimes we used to go fishing without knowing that there are fish under the water or not. Now with this tool we can understand position following fish depth. Also to know the basic condition of the water. Fish Finder can be used in sea, river or lake.
How it works is that sonar sensor with sound waves that would reflect the form of the objects that are at 45 degrees below the sensor. To do that is by putting transducer about 9 meters in length either by using the stick before the fishing rod. This sonar can detect the start of the depth of 0.7 Metres to 100 Metres.
This entry was posted on Tuesday, June 8th, 2010 at 10:10 am and is filed under Technology Info. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.
