CS255574B1 - Approach search radar connection - Google Patents

Abstract

Engaging in landing radar consists in controlling the reception sensitivity paths at low angles scanning antenna glisády. The essence of the solution is in it. that circuit generating control pulses is appropriate controlled by constants stored in memory circuits generate distance and circuit information generating angular information. Output circuit control pulses control sensitivity the receiver.

Description

(54)

Wiring in the landing radar

The engagement in the landing radar consists in controlling the sensitivity of the reception path at low angles of sensing the glisade antenna. The essence of the solution is that. that the control pulse generating circuit is suitably controlled by the constants stored in the memory, the circuit generating distance information and the circuit generating angular information. The output control pulses of the circuit control the sensitivity of the receiver.

(52) Int. c6

G 01 S 7/02

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The invention relates to a landing radar engagement.

In civil aviation operations, internationally standardized means of landing control are landing radars; type PAR. In these radars is often a phenomenon occurrence of parasitic echoes from the aircraft in the glisade. This phenomenon is reflected in the image of the position as a parasitic echo at a low elevation angle at approximately the same distance * as the basic echo from the aircraft, given by the passage of the aircraft through the main antenna beam. The parasitic echo proceeds in parallel with the basic echo from the aircraft.

The parasitic echoes are the reflection of the electromagnetic energy emitted by the glisade antenna from the earth's surface in an area where the glisade antenna senses space around a horizontal plane interlaced with the center of the glisade antenna. This can be demonstrated by the calculation referenced to Figure 2 for the terrain, which is an ideal plane.

d · tg / 3 + V-, y = are tg ------------------------------- = d + d p

The course of the angle θ at the distance of the aircraft d from the point of contact BD is shown in Fig. 3.

For terrain monotonically rising from the radar, the following applies:

d sin phi> + V-, cos <9. cos (β + ()) oC = are tg ---- d cos / 3 + cos (+3 + o) (d - V,) where δ is the angle of inclination of the terrain from the horizontal plane intersected by the center S of the radar antenna.

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For the monotonous terrain descending from the radar, the relation:

sin (3/5 +). d.sec / 3 + cos S = are tg ---- - r cos (fi> + o). d.sec / 3 + V s sin o + d _p where 5 is the angle of the terrain descent from the horizontal plane intersected by the center S of the radar antenna.

The above drawback is overcome by the present invention.

Since the parasitic echo from the aircraft occurs at low sensing angles of the glisad antenna, it is proposed to control the sensitivity of the receiver at the low angles of the glisad antenna depending on the length and elevation angle.

The principle of connection in the landing radar, where between the receiver and the glisad antenna is connected circuit for generating the angular position information of the glisad antenna lies in accordance with the invention. to which the second input is connected, the output of the distance information generating circuit and to the third input of said control pulse generation circuit is the output of the permanent memory, the output of the control pulse generation circuit being connected to the control input of the receiver.

During flight tests of PAR type devices with an impulse power of 150 kW, the width of the glisade antenna beam 0,6 ° and the reflective surface of the aircraft about 8 m was proven high efficiency of the verification pattern circuits according to this material. The parasitic echoes on the indicator screen were suppressed, which significantly improved the conditions for the dispatcher's work compared to the current situation.

The invention will be described according to the attached Fig. 4, which shows the connection in the radar. The landing radar glisade antenna 1 is connected by 3 angular information generation circuits 2, whose output angular information is connected to the input of the control pulse generation circuit 6. A remote input of the target information from the remote information generating circuit 6 is connected to the second input of the same circuit. At the third input of said circuit for generation of control pulses is connected a memory output 5 supplying constants given by calculation or flight test results, or by terrain measurement. This memory 4 is of the ROK or RV / Ie type of permanent memory. From the output of the control pulse generation circuit 6, control pulses are supplied to the actual radar receiver Qru.

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If the angular and target distance information are within the intervals given by the limits stored in memory 4, it generates a control pulse whose amplitude is given by the value stored in memory 4. Control pulses control the sensitivity of the receiver 6 either at intermediate frequency or more preferably attenuation in microwave path. The memory 8 may be of the type ROK (read only) for a stable landing radar or of the type R'® (read read) for operatively entering constants, which is suitable for mobile devices.

Claims (1)

SUBJECT OF THE INVENTION A connection in a landing radar wherein a receiver for generating angular position information is connected between the receiver and the glisade antenna, characterized in that the output of the angler information generating circuit (2) is connected to one input of the control generating circuit (5) the second input of which the remote information generating circuit (3) is connected and the third input of the control pulse generating circuit (5) is connected to a memory output (4), the output of the control pulse generating circuit (5) being connected to via the control input of the receiver (6).