RU2052831C1 - Target angular coordinates meter for surveillance radar - Google Patents

Abstract

FIELD: measurement technology. SUBSTANCE: meter has antenna 1 with elevation angle transmitter 2, angular discriminator 3, angle computing unit 4, angular error estimating unit 5, bearing sensitivity evaluating unit 6. EFFECT: improved design. 1 dwg

Description

 The invention relates to automatic radar meters of the angular coordinates of the target and is intended to work in surveillance radars.

 Known directly counting radar meters of the angular coordinates of the target, containing a series-connected antenna, an angular discriminator and a device for calculating the angle.

 Known meters provide an estimate of the angular coordinates of the target Δθ by generating an angular error signal U and converting it according to a known sensitivity to angular error μ, i.e.

(1) Чувствительность μ к угловой ошибке представляет собой заданное значение крутизны пеленгационной характеристики или скорость изменения угловой ошибки V относительно равносигнального направления антенны θ:
μ U $\genfrac{}{}{0ex}{}{\text{l}}{\text{θ}}$ (2)
Недостатком устройства является снижение точности измерения угловых координат цели из-за ошибок, обусловленных флюктуациями отраженного от цели сигнала (следовательно, и сигнала угловой ошибки U) и систематическими ошибками, вызванными неправильной калибровкой чувствительности к угловой ошибке μ.Δθ

(1) The sensitivity μ to the angular error is the specified value of the steepness of the direction-finding characteristic or the rate of change of the angular error V relative to the equal-signal direction of the antenna θ:
μ U $\genfrac{}{}{0ex}{}{\text{l}}{\text{θ}}$ (2)
The disadvantage of this device is the decrease in the accuracy of measuring the angular coordinates of the target due to errors caused by fluctuations in the signal reflected from the target (and therefore the signal of the angular error U) and systematic errors caused by incorrect calibration of the sensitivity to the angular error μ.

The closest in technical essence is a direct-reporting single-pulse measuring device of the angular coordinates of the target, containing an antenna with a bearing sensor, an angular discriminator and an angle calculation unit, the first input of which is connected to the output of the angular discriminator, and the second input to a calibration voltage source corresponding to the sensitivity to angular error μ
An antenna of amplitude or phase sensitive type serves for spatial modulation of the parameters of a radar signal (amplitude or phase). An angular discriminator, for example, of a single-pulse type, contains devices for frequency conversion, amplification, filtering and normalization of the signal, as well as an angular error signal generating unit, which is uniquely associated with the angular coordinate of the target.

 The disadvantage of this device is the decrease in the accuracy of measuring the angular coordinates of the target due to systematic and random errors. Systematic errors include sensitivity calibration errors.

 These errors are caused by the nonlinearity of the palpation characteristic, the spread in the steepness of the direction-finding characteristic from product to product, and incorrect calibration μ, which should depend on the level of the received signal.

 A well-known meter cannot fundamentally eliminate systematic errors due to the lack of connection of the calibration voltage source with an angular discriminator (UD) and a bearing angle sensor (DUP) of the antenna. Random errors include the measurement of the signal of the angular error U due to fluctuations in the input signal and the intrinsic noise of the receiver (angular discriminator).

 The drawing shows a functional diagram of the meter of the angular coordinates of the target for the surveillance radar.

 The target angular coordinate measuring instrument for the surveillance radar comprises an antenna 1 with a bearing sensor 2, an angular discriminator 3, an angle calculation unit 4, an angular error estimation unit 5, and a direction finding sensitivity estimation unit 6.

(3)

(4)
Сглаженное значение сигнала угловой ошибки

, рассчитанное по формуле (3), повышает точность сигнала угловой ошибки U в

раз, где N количество измерений U.Blocks 1-4 of the proposed meter and prototype are identical. Blocks for estimating angular error and direction-finding sensitivity (5 and 6) can be made in the form of smoothing filters, the inputs of which receive signals of angular errors U _i from the output of angular discriminator 3 and signals from the angle sensor of the bearing θ _i (block 2). Blocks 5 and 6 implement the following dependencies with discrete signals arriving at them:

(3)

(4)
The smoothed value of the angular error signal

calculated by formula (3) increases the accuracy of the signal of the angular error U in

times, where N is the number of measurements of U.

по формуле (4) учитывает крутизну рабочего участка пеленгационной характеристики, одновременно сглаживая флюктуационные ошибки, когда калибровочные значения μ, снятые заранее (без учета реальных измерений U_i и θ_i) имеют ошибки нормировки и калибровки, например ошибки нормировки составляют при U 0,5^о, σ_θ 180-280% от ошибки той же цели на оси антенны (σ_θРНС).The calculated value of direction-finding sensitivity

according to formula (4), it takes into account the steepness of the working section of the direction-finding characteristic, while smoothing out fluctuation errors when calibration values μ taken in advance (without taking into account real measurements U _i and θ _i ) have normalization and calibration errors, for example, normalization errors at U 0.5 ^о , σ _θ 180-280% of the error of the same target on the axis of the antenna (σ _θРНС ).

и пеленгационной чувствительности

As a result, at the outputs of blocks 5 and 6, smoothed values of the angular error signals are formed

and direction finding sensitivity

Claims (1)

 ANGULAR COORDINATE MEASURER OBJECTIVES FOR A SURVEY RADAR, comprising an antenna with a bearing of the angles of the bearing, an angular discriminator and a block for calculating angles, made, for example, in the form of a divider, the antenna output being connected to the input of the angular discriminator, characterized in that, in order to improve the accuracy of measuring angular coordinates, the angular error estimation block and the direction-finding sensitivity estimation block are introduced into it, and the output of the angular discriminator is connected to the first inputs of the angular error estimation block and the bearing estimation block sensing sensitivity, the output of the bearing angle sensor is connected to the second inputs of the angular error estimation unit and the direction-finding sensitivity estimation unit, the outputs of which are connected respectively to the first and second inputs of the angle calculation unit.