positional autonomous hydrophysical measuring station
As the main measuring instrument in the course of studies of the variability of the hydrophysical, hydrological and hydrochemical characteristics of the marine environment, as well as the solution of environmental problems, SDB MRAT FEB RAS creates monitoring technologies for the marine environment through which it is possible to control the space-time characteristics of physical fields. The solution of this problem led to the creation of a positional autonomous hydro-physical measuring station (PAHMS). The station is an element of an automated system for integrated monitoring of the water sphere. This allows to accurately and effectively assess the degree of man-made impact on the environment.
It is a sealed container with sensors of hydrophysical fields installed in it.
In the design of the PAHMS there is a VHF communication antenna, a hardware module, a power module, a winch and a set of measuring sensors. The total number of sensors is from 6 to 9. The basic set of sensors is a flow sensor, a pressure sensor, a temperature sensor, an oxygen sensor, a fluorescent sensor of polycyclic aromatic hydrocarbons, a gamma spectrometer. In addition, the station is equipped with a 3-axis position sensor.
The measurement error is:
oil products – 2%
phenol, formaldehyde – 1%
dissolved organic matter – 3%
gamma radiation – 2%
the flow velocity – 0.1%.
Time of continuous autonomous work of the station is up to 100 hours. This allows 100 probing cycles up to 200 meters depth. In the standby mode, the station can be up to 30 days. The autonomous work of the station is provided by 12 V batteries and a capacity of 26 A / h.
PAHMS maintains its working capacity when the sea waves up to 6 points and the speed of currents in the area of 1 node. Weight of PAHMS in the air (positive buoyancy) with a basic set of sensors is 56 kilograms.
Management of PAHMS
PAHMS is able to move in a layer of sea water according to a given program, ensuring continuous registration of vertical distributions (profiles) of parameters of the aquatic environment. In measurements of increased accuracy, the station can stop or “hang” at the right time to produce accurate measurements at given horizons.
The software allows you to perform measurements at a set time and at different horizons, as well as quickly manage the station’s ascent and immersion. The measurement program is set by the operator remotely over the air.
Transmission of the measurement results is carried out on the VHF modem. In the absence of line of sight between the station and the control point, data transmission is carried out using a satellite radio modem, which transfers them to the FTP server, where they can be taken by the user.
When the surface is reached, the radio modem of the station transmits the received data to the center for collecting and processing information on VHF or satellite communication system. After transferring data, the PAHMS is immersed to a specified depth.
The communication range via VHF modem in the line of sight is 20-40 km, with the use of a satellite channel – unlimited.
This design feature creates a number of advantages:
- The ability to transmit data in real time (since the antenna is located inside the ocean buoy, which is constantly on the surface of the sea);
- Increasing the permissible depth of the water area at the installation site to 4,000 meters;
- Increase of storm resistance to 9-10 points;
- Ability to install an autonomous meteorological station with data transmission over a radio channel;
- The possibility of determining the presence of oil products on the sea surface;
- Increase the number of sensors can be used.
PAHMS can be equipped with additional underwater measuring facilities depending on the tasks assigned.
A set of several stations can be combined into an information and measurement network that will provide dynamic monitoring of the hydrophysical fields of the underwater space.
Components of PAHMS
- Communication antenna of VHF band;
- Hardware module;
- Measuring sensors:
a) current sensor Doppler Current Sensor 4420;
b) pressure sensor Prestige Sensor 4117;
c) temperature sensor Temperature Sensor 4060;
d) conductometer Conductivity Senoc 4319;
e) oxygen sensor Oxygen Optode 3830;
- Power module (lithium battery);
- The underwater winch;
- Cable winch (Kevlar);
Main technical characteristics of PAHMS:
maximum working depth – up to 200 m;
the maximum number of measuring sensors is 6 pcs. (the composition of the measuring sensors can be changed depending on the measured parameters of the aquatic environment, the technical characteristics of the measuring sensors are indicated in the passports);
total electrical energy (W / h) – 3800 (with a battery voltage of 24V).
Overall dimensions of the probe station PAHMS:
in the transport position (mm) – 400 × 400 × 2000;
in the working position (mm) – 400 × 400 × 3500;
the mass of the sounding station (kg) is 54.
Measuring platform on the surface, transmits the accumulated measurement information