Abstract: A low cost simulator for training electronic warfare operators to recognize signatures of various emitters. The simulator consists of a card which can be plugged into an IBM PC or compatible computer. Through the computer, various characteristics of one, or a plurality of emitters are entered. The simulator, using an existing digital signal processing (DSP) chip generates a replica of a signal received by a radar system receiver from one, or a plurality of emitters.

Abstract: A portable radar simulator which when connected to a transmitting means s as a magnetron generated microwave threat transmitter simulates up to 2048 pre-programmed radar signatures. The portable radar simulator comprises a replaceable Erasable Programmable Read Only Memory (EPROM) which will hold up to 2048 pre-programmed radar signatures. Selection of a particular radar threat to be simulated is entered by an operator via thumbwheel switches located on the front panel of the simulator. The portable radar simulator simulates such radar parameters as jitter, stagger, frequency hop, simple and complex scans, pulse repetition intervals and frequency pulse widths.

Abstract: A synthesizer combines frequencies for multiple targets, accumulating the phase components separately and allowing the targets to change velocity separately. The amplitude of the simulated signal at the phase secified is generated using a method that combines coarse and fine angle components of the desired angle signal allowing small high speed memories to be used. A first ROM is addressed by high order bits of the phase component and a second ROM by the lower order bits. The outputs of the first and second ROM's are multiplied and then added to the output of the first ROM producing the amplitude of the desired phase. The system also allows the amplitude of the signal being synthesized to be modulated by multiplying the synthesized digital value by an amplitude modulator. The synthesized amplitudes for each frequency are combined. Digital zero order hold correction removes amplitude distortion from the output spectrum.

Abstract: A portable compact target motion simulation system, adapted to generate simulated target motion for displaying, tracking, and controlling a plurality of simulated targets on a display device for training purposes. The system is operable to generate pre-programmed and dynamic exercises, for training trainees in operating tracking devices, to develop trainee skill in analyzing and responding properly to target motion.The apparatus is totally programmable, and capable of providing targets in any matrix. It includes a target display generator, adapted to store, merge, and transmit timed data signals for driving a target-display device. It further includes a dynamic target motion generator, microprocessor-based, adapted to receive input data identifying the characteristics of particular operator-controlled targets and convert such data into dynamic target motion input data for driving the target display generator.

Abstract: Radar signature simulator for use in electronic warfare and training intercept operators. Recorded video portions of radar signature as they appear at the point of intercept on a video tape recorder are played back to produce video signals. These signals are used to amplitude modululate an RF signal of the desired frequency. The modulated signal is amplified in a linear amplifier and fed to a broadband tansmitting antenna.

Abstract: A short range, high resolution, radar system of particular use in training radar operators. The system transmits very short pulses of a radio-frequency (RF) signal at a very high pulse repetition frequency, PRF.sub.o. A signal pre-processor samples a received baseband radar signal and generates a time-expanded signal which is a replica of the real received radar signal, but with a much lower nominal pulse repetition frequency, PRF.sub.n. The signal pre-processor includes a sampling circuit which receives the baseband signal, and a timing circuit which controls the sampling circuit. The timing circuit operates by causing samples of the baseband signal to be taken at progressively later portions of subsequent pulses. While the radar system is particularly useful in demonstrating radar principles in a classroom setting, it has other applications.

Abstract: A digital information storage and read-out system in which digital elevation and cultural terrain data is read from a magnetic tape in compressed form into an intermediate memory which operates as a speed buffer memory. The data in the intermediate memory is read out to a reconstruction processor in which the compressed data is reconstructed and applied to a scene memory. A nagivation computer determines the instantaneous position of a vehicle with respect to the terrain and controls the reading of data into the scene memory in blocks with the vehicle position occupying a center of scene location. In order to provide a heading up display of the terrain, the data in the scene memory is read out at an angle to its north-up storage orientation and interlaced scanning of pixel data in the scene memory improves resolution and enhances line display.

Abstract: An interactive trainer for electronic countermeasures simulation capable of providing displays of in-flight threats and countermeasures responses representative of an actual combat equipment suite. Threat scenarios are stored in computer memory and recalled at a push-button display console. Default parameters may readily be modified by the operator under software control. The aircraft position with respect to selected threats is displayed in real time superposed on the threat parameters. Displays are identical to that provided by the equipment simulated and reflect the true operational status as preset by the operator.

Abstract: A software controlled generic radar display system using a microcomputer ing a high performance graphics card that drives a high resolution color monitor which displays the radar sweep, compass rose, front panel symbology and diagnostic information. A target generator provides simulated target information that is displayed on the monitor in standard PPI format.

Abstract: This invention relates to a simulator for an installation for locating and guiding a self-propelled, remote-controlled aerial body in motion, wherein said simulator comprises means for simulating the radar, the aerial body in motion and the remote-control emitter, and it may be connected, in place of said radar and said remote-control emitter respectively, at the input of the radar control panel and at the output of the remote-control panel, by means of a switching system.

Abstract: A signal processing mechanism for interpolating elevation data values between successive data points of a terrain map from which a simulated radar return image may be produced employs a signal processing operator in accordance with which input data signals representative of the elevations at successive data points on the terrain map are processed, to derive a continuous interpolated (terrain map) functional characteristic. Interpolated elevation data values at one or more points between successive ones of the original data points are calculated by employing elevation values for successive data points adjacent to those data points between which the one or more additional points of interest are located.

Abstract: A test facility, especially for the seeker or search heads of intelligent guided ammunition, including a target simulator for the reflection of a target signature through the intermediary of antenna elements towards the search head which is mounted on a turntable or rotary member with a flight simulator. Arranged between the target simulator and the search head is a quasi-optical coupling which follows the beam geometry by means of an imaging system and, on the one hand, the search head, as well as, on the other hand, the target simulator are located in or proximate to the applicable focal point of the resultingly produced path of transmission.

Abstract: A null command generator test apparatus capable of operating in either the open or closed loop configuration for testing the Sarcalm system. When operating in an open loop configuration the null command generator test apparatus utilizes the normalized voltage output of the null command generator as the estimator for the beam pointing error. When operating in the closed loop configuration, the test apparatus utilizes either the voltage output of the null command generator or the angle difference between the line of sight to the target and the null direction of the antenna servo simulator to estimate the dynamic pointing errors.

Abstract: A device constructed as simple as possible shall be provided for simulating, in laboratory tests of radar seekers, the conditions of free space with a moving target emitting radar radiation. To this end, a radar anechoic chamber is formed as hollow body pivotable about the radar seeker and serving as ray trap. A radar transmitter is arranged in this hollow body.

Abstract: The areal height and areal reflectivity of source data for defining a landmass are modified in real time in response to the areal reflectivity of the source data, so that the modified values may be processed for generating radar images to be displayed. The images may include stationary three-dimensional features, useful for a high resolution radar, without need to preprocess data or increase bulk storage medium size of landmass data. In addition, the features, which may include industrial, forestial, commercial and/or residential areas, and/or specific detail such as a predetermined airport, may be predeterminedly disposed within a landmass area more realistically to present an image that is to be expected from an actual operating environment.

Abstract: A method for computer aided simulation of complete radar systems under evaluation of the instantaneous power and frequency information comprises the steps of providing a simulation signal representing the instantaneous power spectrum of the transmitter modifying said signal in accordance with the propagation and spreading path to be simulated and in addition modifying said signal in accordance with preselected target properties, modifying the previously modified signal in accordance with particular properties characteristic of the receiver and associated components to be simulated, such as amplifier characteristics, filters, mixers, Doppler stages, analog-to-digital conversion and calculating statistical moments of the first and second order of the resulting signal such as the expectancy value and its variance and indicating the same.

Abstract: A radar return image for display on a cockpit CRT is generated by selectively accessing terrain data compressed and stored in a digital map data base and processing that data to artificially simulate a radar return image pattern on a cockpit display which effectively corresponds that which would otherwise be provided by conventional T/R equipment. Since the compressed data base contains information representative of both the elevation and cultural features of the terrain at map locations that are capable of being intercepted by the aircraft's radar beam, this data may be subjected to signal processing functions to establish pixel intensity control signals by way of which a radar image of a cockpit CRT display is generated.

Abstract: System and method for producing a pattern of radar radiation encountered by a object in the scan path of a radar, commonly referred to as "radar signature". The basic system has a memory containing at least digital amplitude information for each pulse of the signature, digital pulse width information for each pulse, digital pulse-to-pulse interval information for each pulse, scan time information and scan gap information. A digital to analog converter converts the digital amplitude information to a proportional voltage. Timers convert the pulse width information, the pulse-to-pulse interval information, scan time information and scan gap information to intervals of time in sequential fashion. During pulse width times, the output of the digital to analog converter is enabled. The output is disabled during pulse-to-pulse intervals and scan gap time. A controller controls the transfer of amplitude information from memory to the digital to analog converter and controls operation of the timers.

Abstract: A simulator for simulating radar or sonar signals returned to an observation point from a three-dimensional object of non-uniform reflectivity. An imaginary three-dimensional object is defined spatially in the form of a series of three-dimensional regularly shaped elements. Each element has allocated to it a predetermined level of uniform reflectivity.The position of boundaries of the element along an imaginary radial line extending from the observation point are calculated and the reflectivity allocated to points on the line on each side of each of the boundary positions is calculated. A sequence of signals is then generated which is representative of the allocated reflectivities occurring along the length of the line.

Abstract: The simulation of clutter echo return signals for a radar system is accomplished using two sets of diode noise sources, a frequency synthesizer for bandwidth control, multiplexing control, two D/A converters and mixers, a 90-degree sower splitter, and a summer; the output of the summer being the simulated clutter. The two sets of noise sources each produce a digital encoded controlled bandwidth Gaussian noise signal which is strobed by the multiplexing control unit firstly to the pulse repetition interval of the radar system and secondly to the data rate of the radar system. The two strobed D/A converters convert the two digital noise signals into their analog equivalents. The two separate video channels are required to obtain the Rayleigh noise distribution characteristic of clutter. This distribution results when the analog signals from the D/A converters are multiplied with in-phase and quadrature RF reference frequencies in the two mixers, then summed in the summer.

Abstract: Apparatus and methods are disclosed in which a radar target can be electronically disguised to appear like another target.The technique is based on the generation of a desired synthetic target signature that is superimposed on the normal radar echo for the simulation platform. The simulation system consists of multiple antennas with tapped delay lines and signal modulators to provide the means of generating the desired target signal that is extended in angle and range. It is possible to utilize very realistic models of the desired target; the necessary information can be collected on a high-resolution measurement range. The general technique works against any pulsed radar in a monostatic geometry. A modified technique for operation against continued wave and bistatic radars is also discussed. The applications of the technique include the testing of missileborne guidance radars against cooperative targets and electronic countermeasures (ECM) applied to a target vehicle to deceive the radar.

Abstract: Preprogrammed aircraft target information is stored in separate lists of beacon and radar target words each including azimuth, range and amplitude data for a designated target within the current one of a plurality of predetermined azimuth "half" sectors. For each radar target word whose starting and ending azimuth includes the current azimuth, its amplitude data is loaded into the range bin of one of a first pair of high speed RAM data stacks addressed by the range data of the target word. When the radar trigger occurs, the previously loaded data stack is read out sequentially bin-by-bin. An echo pulse is formed by a video data output control for each range bin containing a non-zero value. For a beacon target of valid azimuth, the amplitude data is loaded into the range bin of one of a second pair of data stacks addressed by the range data of the beacon target word. The same amplitude data is loaded into every eighth range bin for which the corresponding bit of the transponder 3/A or C code is a "1".

Abstract: Generating five Gaussian random variable, statistically identical but independent, signals, squaring four of the signals and combining two or four of the signals to provide the target power return, or radar cross section, of Swerling case one or three targets, respectively. Utilizing the fifth Gaussian random variable and dividing it by the square root of the target power return signal, and multiplying the result by the bandwidth of the fifth Gaussian random variable and a scale factor to provide an output signal representative of the target Doppler frequency scintillation.

Abstract: A beam position processor (15) generates address signals representing the spatial coordinates of points on a simulated radar beam, for a plurality of beam directions. The address signals serve for readout of weather information (e.g. cloud intensity, ceiling and base height data) from a data storage means (16) for further processing to form a video signal for display. The storage means (16) is arranged for economy of memory capacity in that the higher order parts of the address are used to read out code words from a database memory (17). Each code word selects one of a set of predetermined cloud patterns in cloud pattern memories (18, 19) and the lower order parts of the address access data corresponding to individual cells of the selected pattern.

Abstract: An active millimeter wave simulator for missile seeker evaluations wherein a missile seeker generates seeker signals and transmits them in the direction of an array of active antenna elements. Range timing signals are delayed in a time delay circuit to simulate a range between the missile seeker and a target. The seeker signals as received by the active antenna elements are supplied to a millimeter wave spectrum analyzer for determination of their frequency. A computer receives the determined frequency and controls a millimeter wave source to generate simulated target response signals with that same frequency but delayed in accordance with the time delay signal. The computer controls a master target control circuit to select a triad of antennas in the antenna array and to generate a phase center in the triad generating the target response signals. The millimeter wave spectrum analyzer further determines the frequency of the target response signals.

Abstract: A synthetic aperture radar (SAR) target simulator for simulating the radar return, or echo, from a target seen by a SAR antenna mounted on a platform moving with respect to the target includes a first-in first-out memory (26) which has digital information clocked in at a rate related to the frequency of a transmitted radar signal and digital information clocked out with a fixed delay defining range between the SAR and the simulated target, and at a rate related to the frequency of the return signal. An rf input signal having a frequency similar to that utilized by a synthetic aperture array radar is mixed with a local oscillator (16) signal to provide a first baseband signal having a frequency considerably lower than that of the rf input signal. The first baseband signal is converted to a plurality of digital words which are clocked into the memory (26) at a rate related to the frequency of the local oscillator (16).

Abstract: Analog video information with a wide range of radar characteristics is converted by a digital scan converter into a standard TV format. The analog video information is converted to digital PPI data and stored in a buffer. The digital PPI data is consecutively integrated on a pulse to pulse basis to eliminate noise. The digital PPI data is then stored in an image memory (RAM). The polar coordinates of each digital PPI data sample are converted to an address of equivalent X, Y coordinates wherein each point along a TV line is an X coordinate and each TV line is a Y coordinate. This address defines the location at which the data is stored in the RAM. Each address of X, Y coordinates uniquely defines a cell in the RAM which is three bits deep, describing eight intensity levels. Data is read from the image memory in time sequence with a TV synchronization signal for display on a TV monitor.

Abstract: Inflight training apparatus is provided for military aircraft radar warning receivers that is plug compatible with the standard receiver processor to provide realistic training scenarios responsive to pilot maneuvering while recording the pilot's actions for post flight analysis. The training apparatus includes inertial navigation equipment to indicate position and attitude of the training aircraft, a memory in which is stored position and types of enemy radars and threats that would be encountered on an actual combat mission, and a processor which receives inputs from the inertial navigation equipment, memory and radar warning receiver control panel to control the standard receiver video display to generate the training scenario thereon. The training display moves, rotates, and is blanked simulating the effects of aircraft altitude and attitude as the aircraft turns, banks and performs other maneuvers which may be navigational or evasive maneuvers.

Abstract: A technique for simulating various signals, such as from radar emitters, in a broad frequency spectrum by generating at any given instant only those of the signals that affect a receiver which is tuned to a particular bandwidth. As the receiver is tuned to a new bandwidth, the simulating system responds by quickly generating any signal or signals that exist in the new bandwidth.

Abstract: The disclosure describes a system for ordering and pairing feature boundary intersections on a sweepline of a simulated digital radar visual display screen in order to arrange a variable length list of data in accordance with a desired order. This ordering and pairing system resolves the correct range order of the intersection pairs for any closed feature shape regardless of boundary convexity, range inaccuracy or possible shape anomalies. The system includes an input data control means (11) having one input connection and a plurality of output connections (14, 16, 18) to store the input data temporarily. There is described two sorting pipelines (12, 13) connected to two of the output connections to receive certain described "key" data in order to sort the data in each respective pipeline in accordance with a desired correct relationship of ranges. A temporary storage means (19) is connected to receive the "non-key" data.

Abstract: An apparatus which simulates signals received by a radar antenna and which is used for teating radar equipment and for training purposes, Two stores are provided to hold the horizontal and vertical polar diagram characteristics of an antenna, respectively. The appropriate values are read out of these stores by signals representing the azimuth and elevation angles of an imaginary target and the antenna, which may be real or imaginary. The outputs from the stores are combined to give a realistic simulated signal. Since the polar diagram characteristics of an antenna may be different for transmission and reception, each store may be provided in duplicate and the outputs from all four stores combined to produce the simulated signal.

Abstract: A circuit injects the signal from a stable localized oscillator past a pin diode switch through a first circulator to a waveguide, a second circuit injects a noise signal from a generating diode through a second circulator to the first circulator to the waveguide, a switching system causes the diodes to function in a coordinated manner.

Abstract: A beam width integrator is provided for a radar simulation system in which a synthetic radar image is generated from echoes comprised of simulated echo contributions. The amount of special-purpose digital equipment required is significantly reduced, together with the overall cost and complexity of the equipment. Data signals which jointly represent an echo contribution are provided in logarithmic form in order to limit the required storage and other logic and to reduce the number of operations required to process the signals. The echo contributions are divided into successive groups, each group comprising a predetermined number of echo contributions lumped to constitute a single set of equivalent signals. A complete echo is represented in uncorrected form by a predetermined number of successive groups. By numeric addition, an average weighting signal is applied to each group of lumped echo contributions to correct for gain profile-originated echo intensity variations.

Abstract: A simulator for simulation of signals of a target radiator includes a first free-running frequency generator operating at a first frequency for simulating the intensity fluctuations of a target radiator, an amplitude regulator connected to the free-running generator for controlling the amplitude of the first frequency, a second free-running generator operating at a second frequency lower than the first frequency for simulating the amplitude and phase of a vectoril target representation, and a frequency divider chain for coupling the first generator to the second generator.

Abstract: The microprocessor-controlled RF modulator apparatus will provide repeatable, controlled scintillation on a test bench generated low-power RF target waveforms for the purpose of providing a target returns with realistic radar cross section characteristics during testing of the F-16 (or any other) fire control radar. The microprocessor-controlled RF modulator apparatus is utilized in line between an RF target signal generator and the target horn to provide a variety of target situations for testing radar hardware and software.