Underwater camera monitoring has become an eye for developing the ocean and all waters, and its application has become more and more extensive.  This paper introduces the function of underwater camera monitoring and several technical problems that should be considered in the implementation and the measures to solve them.

I introduction

With the development of science in developing oceans, rivers and lakes, the scale of underwater projects is getting larger and larger. Underwater camera monitoring has become the eye of developing water areas and its application has become more and more extensive.

Due to the progress of ultrasonic technology, it used to be quite common to use sonar to investigate and observe water conditions, but these are indirect observation methods.  However, direct observation can be done by divers, diving investigation ships and underwater photography. However, these methods have the disadvantages of training divers and the water depth can only be within 50 meters, which is costly, uneconomical and cannot reflect the real situation immediately.  Therefore, underwater camera monitoring has been developed, which is extremely excellent in safety, timeliness, economy and other aspects, and can be used together with video recorders and underwater cameras to obtain better results.

In recent years, with the development of photoelectric technology and the emergence of various new camera components, underwater camera with low illumination and radiation resistance is widely used in harsh environments.  Special optical systems such as infrared, zoom, wide angle, rotary and elevation remote control lenses also improve the performance of underwater camera monitoring and expand its practical scope.

The development of underwater camera monitoring technology mainly includes the development of remote-controlled underwater camera vehicles (self-swimming underwater camera), the miniaturization of underwater camera, and the development of laser camera, ultrasonic camera and radiation-resistant camera.  In the future, with the continuous development of marine and other water areas, underwater camera monitoring system will become an indispensable and important tool.

Second, the role of underwater camera monitoring

Underwater camera monitoring is mainly used for monitoring underwater operations. At present, it has been used in the following fields:

(1) Civil engineering in the sea: preliminary investigation of reef and seabed conditions, project management, completion inspection, and as auxiliary equipment for underwater operations such as underwater bulldozers.

(2) Investigation and observation of water resources, investigation and study of seabed minerals, seabed oil fields, pearls, corals and various seaweeds.

(3) Fishery: Investigation of the actual situation of fishing nets and artificial reefs set up in a specific water area, detection of fish schools, etc.

(4) Investigation of sunken ships, monitoring of salvage process, and inspection and evaluation of underwater parts of ships to be repaired, etc.

(5) Monitoring of underwater sludge for hydropower generation and internal inspection and welding of water supply pipelines in power plants.

(6) Monitoring of rivers and reservoirs and regular inspections of other submerged structure facilities.

(7) submarine underwater reconnaissance.

(8) On-site monitoring equipment for nuclear power plants.

Third, the influence of light absorption and scattering in water on image quality

There are two differences between underwater camera monitoring and terrestrial camera monitoring in optics:

(1) the attenuation of light is very large;

(2) The scattering of light is quite serious due to various pollutants in the water.

The above two points are the fundamental problems of the image quality of left and right cameras. In water, the attenuation of light varies with the nature of seawater, plankton and other suspended substances, and varies with the wavelength of light. For the first problem, if it is only the attenuation of light, it can be solved by strengthening the light source.  However, the scattering phenomenon of the second point light increases with the increase of light. Photography is taken when there are more suspended substances in the water, just like the fog on the ground, which reduces visibility.