RU189289U1 - DIGITAL IMITATOR OF RADAR SIGNALS FROM THE UNDERSTANDING SURFACE TO DEVELOP THE SYNTHESIZED APERTURE MODE - Google Patents

Abstract

The utility model relates to a technique for modeling aircraft systems, in particular, to simulators of a radar complex with aperture synthesizing operating in the mapping mode of the earth's surface, and can be used to study and test autofocus algorithms and digital algorithms for processing radar complex with aperture synthesizing .The technical result is achieved due to the fact that a digital simulator of radar signals from the underlying surface The synthesized aperture mode contains a programmable logic controller, a digital I / O board with a timer, a central processor, a random access memory, a reflective memory board for exchanging information with subscribers of the computer network of the polyunature modeling complex, a reflective memory output card, and a graphics adapter, and the programmable logic the controller with its output is connected to the input of a digital I / O board with a timer, which is connected to the central processor m, operational memory, reflective memory card, graphics adapter and reflective memory card data output via the data bus, the parameters of the reflected signals are calculated in real time on the graphics adapter, taking into account the correction for the difference in the time of arrival of radar control commands and information from the navigation system, which is measured in a programmable logic controller and a digital I / O board with a timer.

Description

The utility model relates to the technique of modeling aircraft systems, in particular, to simulators of the radar complex with aperture synthesis (PCA), operating in the mapping mode of the earth's surface, and can be used to study and verify algorithms for autofocusing and digital algorithms for PCA signals.

The simulated PCA aperture radar signal simulator and the signal simulator through a radio channel that receives a PCA probe signal in real time, transfers it to an intermediate frequency, digitizes, delays the scene signal with a corresponding radial speed to the beginning, rolls it with the offset, previously calculated for each update cycle impulse response of the scene, compensates for the effect of the entered offset of the impulse response of the scene on the simulated radar image the scene transfers the received signal to the carrier frequency and re-radiates towards the PCA. (Patent of the Russian Federation No. 2522502 C1 dated December 10, 2012).

The closest analogue of the prototype is a simulator of radar signals (RF Patent 42327 U1 of 07/19/2004), the essence of which lies in the fact that the simulator of radar signals (Operational documentation of the integration stand SI-21-93I, GosNIIAS, M., 2000, book ED 6, pp. 11-14)), which includes two power dividers and a modulator, introduced (M-1) additional modulators and attenuators, (M + 1) additional mixers, as well as analog-digital and M digital-analog converters, (M + 1) processor modules, frequency converter and local oscillator. The proposed simulator provides the possibility of working out radar complexes in the laboratory by forming and introducing into each channel a complex of signals simulating the radar signals reflected from the target.

Known simulators of radar signals provide the ability to simulate a signal from only a few point objects, which is not enough to produce a synthesized radar image that is close in quality to a photographic image. To achieve such a result and to make a full debugging of the PCA mode and autofocusing algorithms on a complex radar scene, it is necessary to calculate the reflected signals from the underlying surface fragment of at least 128 × 128 resolution in real time.

The task of the utility model is to develop a system that implements a simulation of the reflected signals from the earth's surface in real time for a system for the digital processing of airborne radar signals.

The technical result achieved in the implementation of this utility model is to improve the efficiency of work on the ground-based ground-based XRD system by providing real-time on-board radar equipment with all the necessary information for operating in the ground-surface mapping mode taking into account the correction for the difference in arrival time radar control commands and information from the navigation system.

This technical result is achieved due to the fact that the digital simulator of radar signals from the underlying surface for testing the synthetic aperture mode contains a programmable logic controller (PLC), a digital input-output card with a timer, a central processor, random access memory, a reflective memory card for information exchange with subscribers of the computer network of the semi-natural modeling complex, a reflective memory output card and a graphics adapter, with the Its output is connected to the input of a digital I / O board with a timer, which is connected to a central processor, random access memory, a reflective memory card, a graphics adapter and a reflective memory card for data output via the data bus, the parameters of the reflected signals are calculated in real graphic adapter, taking into account the correction for the difference in the arrival time of the radar control commands and information from the navigation system, to It is measured in a programmable logic controller and a digital I / O board with a timer.

FIG. 1 shows a structural block diagram of a simulator of radar signals reflected from the underlying surface where, 1 is a programmable logic controller (PLC), 2 is a digital I / O board with a timer, 3 is a reflexive memory board, for receiving information from subscribers of the KPM computer network, 4, 7 - data bus, 5 - a chipset that performs the function of a glue component that provides the interaction of the central processor (CPU) with various types of memory, input / output devices, controllers and adapters, as directly as itself (and having some of them in its composition), and through other controllers and adapters, using a multilevel bus system, 6 — a central processor, 8 — a graphics adapter, 9 — random access memory (RAM), and 10 — a reflective board memory data output for the issuance of the calculated reflected signals in the computer network KPM.

The utility model is as follows. The simulator of radar signals reflected from the earth's surface is a body arranged in accordance with the block diagram shown in figure 1. At the input of the PLC 1, clock pulses from the radar and navigation system are fed, after which a positive pulse is generated at its leading edge level of +5 V until the arrival of the clock pulse of the radar. As long as a logical unit is kept at the PLC digital output, the 8 MHz counter of the timer board 2 is incremented, thereby making time measurement. On the falling edge of the clock pulse of the radar, the value of the digital output of the PLC 1 is reset and an interrupt is formed, according to which the counter value can be read and taken into account in the calculation of the time correction for synchronizing the navigation parameters with the radar parameters in order to preserve coherence when receiving reflected signals. Using the clock pulse of the radar received by the PLC 1, the navigation and radar parameters from the input area of the reflective memory 3 and the data bus 4 are read from the chipset 5 into the RAM 9. The software part located in the central processor 6 on Based on the data from RAM 9, the position of the LA at the moments of radiation of the probe pulses is predicted. The prepared data on the data exchange bus 7 is transmitted to the graphics adapter 8, on which the reflected radar signal from the underlying surface is calculated. The results of the calculations are returned by returning to the board of the reflective memory of the data output 10 for the output information to be used by the end user.

The advantage of the utility model lies in the simplicity of the design, which makes it possible to group the used computing devices, preferably as part of an industrial computer, and also to scale up the computing power by increasing the number of graphics adapters to calculate the reflected signals from a larger number of resolution elements.

Claims (1)

Digital simulator of radar signals from the underlying surface for testing the synthetic aperture mode, characterized in that it contains a programmable logic controller, a digital I / O board with a timer, a central processor, random access memory, a reflective memory card, moreover, a programmable logic controller with its output is connected to the input of a digital I / O board with a timer, which is connected to the central m processor, random access memory, reflective memory card, graphics adapter and reflective memory card data output via the data bus, the parameters of the reflected signals are calculated in real time on the graphics adapter, taking into account the correction for the difference in the time of arrival of the radar control commands and information from navigation system, which is measured in a programmable logic controller and a digital I / O board with a timer.

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