ATV ultrasonic tomography wide cross-section flow meter for wireless 4G measurement of hydrology and water conservancy

On March 16, 2016, the Ministry of Ecology and Environment announced the "13th Five Year Plan for the Establishment of the National Surface Water Environmental Quality Monitoring Network". This plan set up a total of 2767 national control sections (points), of which a total of 717 trend research sections were not assessed, and the remaining 2050 sections are the national surface water assessment sections (hereinafter referred to as the "national examination sections").
The national examination section belongs to the evaluation, assessment, and ranking monitoring section (point) of the National Surface Water Environment Monitoring Network, with the core of improving water environment quality, meeting the current environmental management needs of basin water pollution prevention and control target task assessment and urban water environment quality ranking. The characteristics of the national examination section: wide section, with low flow operating conditions throughout the year.

Against the backdrop of the substantive operation stage of the river basin chief system at all levels, various river basin management bureaus have begun to seriously and actively play a role in basin coordination, such as the joint meeting of river chief system, floating object monitoring, cross-border river and lake management, ecological flow regulation, and other water control mechanisms. Each unit should attach great importance to fully achieving the ecological flow and flow guarantee goals of the Ministry of Water Resources, especially in the scheduling of dry seasons. The river chief offices of each basin will fully play the role of basin coordination, continuously improve the supervision and coordination capabilities of basin rivers and lakes, further deepen and improve the "basin+region" collaborative water management mechanism, coordinate and promote the coordinated management of upstream and downstream, left and right banks, and main and tributaries, and collaborate with various cities in the basin to solve the key and difficult problems in the management and protection of basin rivers and lakes, and jointly promote the clean and beautiful water in the basin.

Acoustic technology used to occupy an important position in marine environmental observation, but with the expansion of its application, it has also become one of the important means in the measurement of other water bodies. Acoustic tomography technology, especially the application of 15-88K frequency acoustic tomography, has also been transferred from estuaries and coasts to measurements of surface water, groundwater, and other water bodies.
The ATV acoustic tomography cross-sectional flowmeter utilizes underwater acoustic reciprocity transmission (also known as bidirectional acoustic transmission) for acoustic tomography (temperature flow) inversion calculation, and uses a Fourier model to reconstruct two-dimensional sound velocity, temperature field, and flow field.

Sound waves have superior propagation characteristics in water and are an effective form of radiation for long-distance transmission of energy and information in surface water. Because the layering, peak surface, internal wave, reflection, scattering, absorption, surface and bottom boundaries of water all affect the propagation, sound waves carry a lot of Pathogen transmission information in the process of propagation in water. By analyzing the frequency, phase, time, multi-path structure and other characteristics of acoustic signals, a lot of water information can be deduced.

Tomography technology is an inversion observation method that can use acoustic radiation to penetrate the measured medium from different angles, and invert the properties of the measured medium by measuring the differences in its absorption and propagation time. Acoustic tomography is the use of this technology to invert temperature and flow field parameters using the measured propagation time changes. The inversion will take into account changes in parameters such as temperature, salinity, and depth.
The measurement of cross-sectional flow only requires key flow velocity data, so it is not necessary to obtain accurate flow field distribution of each profile, so there is no need to perform inversion through multi-dimensional acoustic monitoring data. By relying on the time variation of the interaction between direct acoustic waves and multipath waves at two points, the two-dimensional average flow velocity of the cross-section can be inverted. By utilizing the principle of high-frequency (1 second cross reciprocity) reciprocity transmission acoustic tomography, rapid measurement can be achieved with limited investment, and the system measurement cycle is 5 seconds.

After the ultrasonic signal is emitted from the host, it reverberates with direct acoustic waves and multipath waves within a range of 65 degrees, and the complete signal is obtained from the host; After reciprocity, the slave sound wave is received by the host through the same channel sound wave; The acoustic signal can basically fully reflect the flow velocity field attributes of the entire water crossing section, representing the average acoustic characteristics of the water crossing section. The back and forth sound information is inverted through tomography to obtain time variation data, thereby converting the average flow velocity value of the cross-section.

The master and slave machines synchronize time service through the Beidou satellite.

Below: Supporting multi-parameter wireless LED display screen:

Various types of installation brackets can be selected based on on-site installation conditions or processed on-site according to requirements:

The water level elevation can be selected from three types: radar, ultrasonic, and static pressure. Please communicate with the technical personnel during the scheme confirmation stage before installation!