SU873192A1 - Gas detector - Google Patents

Description

(54) GROUND RECORDER

I

The invention relates to meteorological instruments and can be used at meteorological stations for recording thunderstorms.

A device for recording lightning discharges, comprising a serially connected antenna, a matching device, three parallel chains, each of which contains a filter and a threshold device, a coincidence circuit, a pulse extender and a recorder 1, is known.

However, this device does not sufficiently reduce the influence of local electromagnetic interference of non-hazardous origin on the registration results. So, for example, if the source of electromagnetic interference of non-light origin is located near the antosh, then the signals at the outputs of all three parallels of the 1 st chains will be of sufficient magnitude and such interference will be recorded as a thunderstorm discharge.

The closest to the invention is a ground receiver containing a series-connected main antenna, a selection unit

and a recording device, as well as additional antennas 2.

However, in this ground receiver, the analysis does not take into account the relative level of signals induced in the antennas, which leads to a false recording of local electromagnetic interference as lightning discharges.

The purpose of the invention is to reduce the effect of local electromagnetic interference of non-hazardous origin on the registration results.

This goal is achieved by c. the ground recorder entered chains, each of which consists of consecutively connected subtractor and pulse shaper units, as well as a Banning circuit connected between the selection unit and the recording device, one of the inputs of each subtraction unit being connected to the main antenna, and the other to one of the corresponding additional antennas, and the control input of the Inhibit circuit with the outputs of the chains.

FIG. 1 shows the block diagram of the proposed ground register; in fig. 2 - plan

Place 1 on the terrain of the main and additional & aerial antennas.

The warning transmitter (Fig. 1) contains serially connected main antenna 1, selection unit 2, scheme 3 Prohibition, recording device 4. The output of main antenna 1 is also connected to blocks 5-7 of subtraction. Other inputs of blocks 5-7 of the subtraction are associated with additional antennas 8-10, which are located at some distance from each other (ten meters). The outputs of the subtraction blocks 5-7 are connected via pulse drivers 11-13 to the inputs of the circuit OR 14, the output of which, in turn, is connected to the control input of the circuit 3 Disable. Serially connected to each other are BLK 5 subtraction and shaper 11 pulses, block 6 subtraction and shaper 12 impulses | The owls, as well as the subtraction unit 7 and the pulse shaper 13, form additional chains that analyze the difference of the amplitudes of the signals received from the main antenna 1 and the additional antennas 8-10.

The device works as follows.

In a lightning discharge, an alternating electromagnetically-induced field appears in the surrounding space, the intensity of which at the points where the antennas 1, 8, 9, 10 are located is approximately the same. This electromagnetic field is sensed by the main antenna 1 and additional antennas 8-10. The signal from the output of the main bit 1 arrives at the input of the selector unit 2 where its amplitude and frequency analysis is performed. If the signal at the input of the selection unit 2 in a certain frequency band exceeds a predetermined threshold level, then a standard amplitude pulse appears at its output. This impulse passes through the Taffet circuit 3 and is recorded in device 4.

Local electromagnetic interference by a non-hazardous origin cannot simultaneously produce approximately identical signals at the output of antennas 1, 8, 9, 10. This causes a difference signal to appear at the output of one or several blocks 5-7, the amplitude of which will be sufficient to start one or more formers 11-13 pulses. The operation of any of the formers 11–13 pulses leads to the flow through the circuit 14 OR to the control input of the circuit 3 A prohibition of such a voltage that blocks the passage of signals from the input of the selection unit to the recording device.

The ground plan of the main 1 and additional 8 to 10 antennas is shown in FIG. 2. In prncnpe device can work with two antennas, for example with antennas 1 and

8. But in this case it does not eliminate the effects of local electromagnetic interference if the sources of these interferences are located at equal distances from antennas 1 and 8, i.e. on a straight line 15. If there are three antennas, for example 1, 8 and 9, the device does not eliminate the effects of local electromagnetic interference if the source of this interference is at point 16, which is the center of the circle 17 passing through antennas 1, 8 and 9. With a location on the ground of four antennas 1 n 8 - 10, as shown in FIG. 2, at the corners of an equilateral triangle and at its center, any local electromagnetic interference of a rogue origin cannot simultaneously impose signals of the same amplitude on antennas I and 8-10.

Thus x) 6papoM, in the proposed device, it is possible to eliminate the influence of electromagnetic interference of a non-thundery origin on the results of a thunderstorm recording. This greatly enhances the quality of the information received and makes it possible to judge the beginning of thunderstorm activity by registering the first signal. In existing lightning recorders, it is impossible to judge the beginning of a thunderstorm activity by single actions, which hinders the operational use of the data obtained in such households as aviation, energy, communications, construction, forestry and agriculture.

Claims (2)

1. USSR author's certificate number 546834, cl. G 01 W 1/16, 1977. 2. Author's certificate. CQfP No. 591784, Cl. 01 W 1/14, 1978 (prototype). 15 .one (Rig2