Abstract: A transceiver for short-pulse radar applications is disclosed in which a shift register or the like is used to collect return signal information in a manner to reduce the number of transmit pulses needed and to increase the speed of determining the positions of multiple scattering objects. In addition, there is also disclosed cooperating transceivers arranged as transponders similarly utilizing shift registers or other pulse sampling techniques to accurately determine the linear distance between them based on relationships between or among propagation time, measured offsets, and internal clock skews. Corresponding methods are also disclosed.

Abstract: A system and a method for distance measurement utilizes a radio system. The distance is measured by determining the time it takes a pulse train to travel from a first radio transceiver to a second radio transceiver and then from the second radio transceiver back to the first radio transceiver. The actual measurement is a two step process. In the first step, the distance is measured in coarse resolution, and in the second step, the distance is measured in fine resolution. A first pulse train is transmitted using a transmit time base from the first radio transceiver. The first pulse train is received at a second radio transceiver. The second radio transceiver synchronizes its time base with the first pulse train before transmitting a second pulse train back to the first radio transceiver, which then synchronizes a receive time base with the second pulse train. The time delay between the transmit time base and the receive time base can then be determined.

Abstract: A method for determining the position of at least one second transmitting and receiving device (3) in respect of a first transmitting and receiving device in a passive access control system operating in the GHz range, comprising the steps of using a radar method, wherein signals (f1, f2) are received in the first transmitting and receiving device on the left-hand side and right-hand side of a modulation frequency (fmod), determining the distance of two signals (f1, f2) closest to the left-hand side and right-hand side modulation frequency (fmod) wherein the distance is proportional to the distance between the first transmitting and receiving device and at least one second transmitting and receiving device (3), so that multipath propagations are not taken into consideration.

Abstract: A distancing system for determining a distance between first and second locations comprising mobile and fixed units. The mobile unit is arranged at the first location and comprises first receive and first transmit portions operating at respective first and second frequencies, first and second baseband processors operating based on first and second clock signals, and a first control portion. The fixed unit is arranged at the second location and comprises second receive and transmit portions operating at the respective second and first frequencies, a third baseband processor operating based on a third clock signal, a second control portion, and a mode switch. The configuration of mode switch circuit allows communication between the fixed and mobile units or a determination of the distance between first and second locations.

Abstract: A system and method for mitigating co-channel interference is disclosed. A radar system detects targets from received signals at an antenna array. The received signals include direct signals and target signals transmitted from remote transmitters. An antenna array receives the signals. A signal processing system is coupled to the antenna array to perform processing operations on the received signals. The processing system includes a primary cancellation component and a secondary cancellation component. A primary illuminator signal is cancelled from the received signals by the primary cancellation component. An adaptive beam former obtains a secondary illuminator signal from the received signals. A reference regenerator regenerates the secondary illuminator signal. An adaptive cancellation filter removes noise from the secondary illuminator signal. The secondary cancellation component mitigates co-channel interference by canceling the secondary illuminator signal from the received signals.

Abstract: A system for measuring distance between a first locus and a second locus includes: (a) at least one beacon device; a respective beacon device of the at least one beacon device being situated at the first locus and transmitting a respective electromagnetic signal; and (b) at least one locator device; a respective locator device of the at least one locator device being situated at the second locus and receiving the respective electromagnetic signal. The respective locator device is situated at a distance from the respective beacon device within near-field range of the respective electromagnetic signal. The respective locator device distinguishes at least two characteristics of the respective electromagnetic signal. The respective locator device employs the at least two characteristics to effect the measuring.

Abstract: A device for data transmission in a motor vehicle and/or from a motor vehicle in its vicinity includes a first transceiver unit in or on the motor vehicle and a second transceiver unit. which is provided in at least one transponder unit whose spatial position relative to the vehicle may be variable or any desired position. In the first transceiver unit is a radar unit equipped for distance measurement, expanded by adding a two-channel data transmission system. The second transceiver unit is also a two-channel data transmission unit, and the microwave frequencies for two-channel communication of the data transmission system are selected so that their difference yields an intermediate frequency which is processable using conventional components in a heterodyne receiver in the reception part of each of the first and second transceiver units.

Abstract: A system and a method for distance measurement utilizes a radio system. The distance is measured by determining the time it takes a pulse train to travel from a first radio transceiver to a second radio transceiver and then from the second radio transceiver back to the first radio transceiver. The actual measurement is a two step process. In the first step, the distance is measured in coarse resolution, and in the second step, the distance is measured in fine resolution. A first pulse train is transmitted using a transmit time base from the first radio transceiver. The first pulse train is received at a second radio transceiver. The second radio transceiver synchronizes its time base with the first pulse train before transmitting a second pulse train back to the first radio transceiver, which then synchronizes a receive time base with the second pulse train. The time delay between the transmit time base and the receive time base can then be determined.

Abstract: A network, sensor and method are provided that utilize the capabilities of impulse radio technology to help monitor and/or control the environment within a building. In particular, the network includes a sensor attached to a first impulse radio unit that is capable of transmitting an impulse radio signal containing sensor related information to a second impulse radio unit. The second impulse radio unit is attached to a control station that uses the sensor related information (e.g., environmental related information, safety related information or surveillance related information) to monitor and/or control the environment within a building. In one aspect of the present invention, the control system can better control and monitor the environment within the building because the sensor may be moved around within the building and reference impulse radio units may interact with the first impulse radio unit to enable the determination of the current position of the sensor.

Abstract: A process and a system for measuring the distance of a moving body (12) from a fixed part (10), characterized the steps of: generating a first alternating signal (r(t)) having a frequency within the radio-wave range or elastic-wave range; emitting the first signal from the fixed part towards the moving body (12); receiving the first signal (r(t)) on the moving body (12) and generating, on the moving body (12), a second signal (s(t)) having a frequency (nf) equal to the frequency of the first signal (r(t)) multiplied by a constant factor (n), the second signal (s(t)) having an initial phase (&phgr;1) equal to the phase (2&pgr;ft1+&phgr;) at the instant (t1) in which it is received by the moving body (12); generating, on the fixed part, a third signal (u(t)) having a frequency (nf) equal to the frequency of the second signal (s(t)) and an initial phase (&phgr;0) equal to the initial phase of the first signal (r(t)); and determining the variation in distance of the moving body (12) in a pre-set time interva

Abstract: A proximity measuring apparatus (70) comprises an interrogator (80) for generating an interrogation signal encoded with a reference signature code comprising concatenated codes and emitting it as interrogating radiation. It also incorporates a transponder (90) for receiving the interrogating radiation, demodulating it to extract its signature code and then remodulating it after a delay period to provide a signal for reemission as return radiation therefrom. The interrogator (80) receives return radiation at its antenna (260) and demodulates it to extract its signature code and then correlates the code with the reference code to determine mutual correlation thereof. The interrogator (80) incorporates a computer (290) for controlling a scan direction of the antenna (260) and for measuring time delay between emission of the interrogating radiation therefrom and receipt of corresponding return radiation.

Abstract: A device for data transmission in a motor vehicle and/or from a motor vehicle in its vicinity has a first transceiver unit (1) in or on the motor vehicle and a second transceiver unit (2) which is provided in at least one transponder unit whose spatial position relative to the vehicle may be variable or any desired position; it is characterized in that the first transceiver unit (1) is a radar unit equipped for distance measurement, expanded by adding a two-channel data transmission system; the second transceiver unit (2) is also a two-channel data transmission unit, and the microwave frequencies (f1, f2) for two-channel communication of the data transmission system are selected so that their difference |f1-f2| yields an intermediate frequency (fIF) which is processable using conventional components in a heterodyne receiver in the reception part of each of the first and second transceiver units (1, 2).

Abstract: A time domain communications system wherein a broadband of time-spaced signals, essentially monocycle-like signals, are derived from applying stepped-in-amplitude signals to a broadband antenna, in this case, a reverse bicone antenna. When received, the thus transmitted signals are multiplied by a D.C. replica of each transmitted signal, and thereafter, they are, successively, short time and long time integrated to achieve detection.

Abstract: Disclosed is a communication device and method for estimating a more accurate vertical position or altitude of a communication device using atmospheric pressure measurements. In one embodiment, a first communication device comprises a pressure sensor for measuring local atmospheric pressure at the first communication device and a transceiver for communicating with a second communication device, wherein the transceiver may be operable to receive barometric calibration information for calibrating a local atmospheric pressure measured at the first communication device and/or to transmit the measured local atmospheric pressure to the second communication device. The first communication device may further comprise a processor for estimating an altitude using the measured local atmospheric pressure and received barometric calibration information.

Abstract: First-arriving-pulse detector (FAP) circuitry includes a correlator circuitry and a threshold circuitry. The correlator circuitry correlates a received signal with a template signal to provide an output signal. The threshold circuitry provides a first-arriving-pulse signal depending on the relative values of the output signal of the correlator circuitry and a threshold signal.

Abstract: Electronic Warfare (EW) systems aboard aircrafts are used to protect them from guided missile by denying threat radar systems the ability to track the aircrafts. In a typical operation, a threat radar system transmits RF signals aimed at the target aircraft. The surface of the target reflects a portion of the incident signal back towards the threat radar antenna where the reflected signal is detected, allowing the threat radar system to determine the target's range, angle and velocity. The present invention relates to EW systems that are dependent on measuring the RF phase of a signal transmitted by a target tracking threat radar. The use of the invented technique will make it possible to implement a robust Electronic Counter-Measures (ECM) technique, known as Cross-Eye, using two airborne platforms. The technique is very effective in preventing a threat radar from tracking a target aircraft and guiding a launched missile to the target aircraft.

Abstract: Systems and methods that may be used to determine the distance between an orbiting satellite and a ground station. A master clock divider circuit generates clock signals derived from a master clock. A transmit code generation circuit generates pseudo-random number codes and processes the pseudo-random number codes to produce a composite signal having positive and negative correlation peaks that is transmitted to the satellite as an analog signal. A digitizing circuit receives the analog signal transmitted from the satellite, and digitizes the analog signal. A frequency domain matched filter match filters the digitized analog signal to produce correlation peaks contained in the digitized analog signal.

Abstract: Systems and methods that may be used to determine the distance between an orbiting satellite and a ground station. A master clock divider circuit generates clock signals derived from a master clock. A transmit code generation circuit generates pseudo-random number codes and processes the pseudo-random number codes to produce a composite signal having positive and negative correlation peaks that is transmitted to the satellite as an analog signal. A digitizing circuit receives the analog signal transmitted from the satellite, and digitizes the analog signal. A frequency domain matched filter match filters the digitized analog signal to produce correlation peaks contained in the digitized analog signal.

Abstract: A network, sensor and method are provided that utilize the capabilities of impulse radio technology to help monitor and/or control the environment within a building. In particular, the network includes a sensor attached to a first impulse radio unit that is capable of transmitting an impulse radio signal containing sensor related information to a second impulse radio unit. The second impulse radio unit is attached to a control station that uses the sensor related information (e.g., environmental related information, safety related information or surveillance related information) to monitor and/or control the environment within a building. In one aspect of the present invention, the control system can better control and monitor the environment within the building because the sensor may be moved around within the building and reference impulse radio units may interact with the first impulse radio unit to enable the determination of the current position of the sensor.

Abstract: A system and a method for distance measurement utilizes a radio system. The distance is measured by determining the time it takes a pulse train to travel from a first radio transceiver to a second radio transceiver and then from the second radio transceiver back to the first radio transceiver. The actual measurement is a two step process. In the first step, the distance is measured in coarse resolution, and in the second step, the distance is measured in fine resolution. A first pulse train is transmitted using a transmit time base from the first radio transceiver. The first pulse train is received at a second radio transceiver. The second radio transceiver synchronizes its time base with the first pulse train before transmitting a second pulse train back to the first radio transceiver, which then synchronizes a receive time base with the second pulse train. The time delay between the transmit time base and the receive time base can then be determined.

Abstract: The invention relates to a method for calculating the range to a moving object by means of a sensor that determines the angle of the object.

Abstract: A tone detector includes at least one circuit (hereinafter “single phase reference matcher”) that not only performs a convolution of an input signal with a reference signal, but also compares the result of convolution with a threshold to determine if there is a match, and if so drives a signal active indicating that tone is present. If there is no match, another circuit (hereinafter “phase shifter”) delays the reference signal by a fraction (e.g. ⅛) of the measuring period, thereby to introduce a phase shift (e.g. &pgr;/8) between the input signal and the reference signal. The “single phase reference matcher” again performs the just-described operation, this time with a delayed reference signal, and repeats the operation as often as necessary (e.g. eight times) to cycle through the entire measuring period, thereby to ensure that tone (if present in the input signal) is detected irrespective of phase, during one of the operations.

Abstract: A method and apparatus for permitting a host automotive vehicle to avoid or mitigate the consequences of a collision between the host vehicle and a target automotive vehicle by using a combination of radar derived target information and transponder information. The host vehicle is equipped with a radar system operative detect the target vehicle and generate target data, and a computer which determines a likelihood of collision with target vehicle. If the likelihood of collision is above a certain level, the computer directs the radar system to transmit a directional interrogation system toward the target vehicle. The target vehicle is equipped with one or more transponders that receive the interrogation signal and respond by transmitting a response signal containing information indicating various dynamic and/or static characteristics of the target vehicle. The response signal is received by the host vehicle and is decoded to extract the target vehicle information.

Abstract: Interrogators, wireless communication systems, methods of operating an interrogator, methods of operating a wireless communication system and methods of determining range of a remote communication device are provided. According to a first aspect, an interrogator includes communication circuitry configured to output a plurality of wireless signals toward a radio frequency identification device and to receive a plurality of wireless signals from the radio frequency identification device; and a processor coupled with the communication circuitry and configured to determine a range of the radio frequency identification device relative to the interrogator responsive to the received wireless signals.

Abstract: A system and a method for distance measurement utilizes a radio system. The distance is measured by determining the time it takes a pulse train to travel from a first radio transceiver to a second radio transceiver and then from the second radio transceiver back to the first radio transceiver. The actual measurement is a two step process. In the first step, the distance is measured in coarse resolution, and in the second step, the distance is measured in fine resolution. A first pulse train is transmitted using a transmit time base from the first radio transceiver. The first pulse train is received at a second radio transceiver. The second radio transceiver synchronizes its time base with the first pulse train before transmitting a second pulse train back to the first radio transceiver, which then synchronizes a receive time base with the second pulse train. The time delay between the transmit time base and the receive time base can then be determined.

Abstract: A high frequency signal transmission apparatus includes a transmitter for transmitting received signals from a signal source as a modulated signal on a high frequency 900 MHz carrier to a remote receiver. The remote receiver converts the high frequency carrier in at least one conversion step to a lower frequency carrier signal. The lower frequency carrier signal carrying the modulated signal is then converted to another carrier signal and retransmitted as a modulated second signal to another remote receiver capable of demodulating the signal and broadcasting the audio sounds or video images. The oscillators in the transmitter and receiver are selectable to operate at discrete frequencies. Automatic fine tuning control is provided in the receiver to accommodate drift of the oscillator in the receiver.

Abstract: A collision avoidance system utilizes a satellite navigational system to continuously determine object motion parameters relative to the earth's surface and exchanges this information with other objects. The system calculates collision potential with other objects that are stationary or in motion based on the exchange of the motion parameters. Evasive actions are calculated with congested space and altitude floor taken into account. The system determines collision potential between two or more objects or can utilize a single ground monitor to perform the collision potential calculations between all participating objects.

Abstract: In a bus type LAN, the data transmitted from a terminal (14) is detected by an adapter (1) connected to one end of a bus (3), and in response thereto the adapter (1) transmits a pulse signal onto the bus (3). An adapter (2) connected to the other end of the bus (3) receives the data transmitted from the terminal (14) and detects its source terminal address. A difference in time between the arrival of the data from the terminal (14) and the arrival of the pulse signal from the adapter (1) is measured by a counter circuit (21), and the count value obtained is stored in a memory (23), forming a pair with the corresponding source terminal address. Thus, the count value can be obtained for each terminal during the normal operation of the LAN. The data of the memory (23) are extracted by a personal computer (5), where the physical position of each terminal is calculated in accordance with the bus propagation velocity, and is displayed or printed out as a physical constitution diagram.

Abstract: A system and a method for distance measurement utilizes a radio system. The distance is measured by determining the time it takes a pulse train to travel from a first radio transceiver to a second radio transceiver and then from the second radio transceiver back to the first radio transceiver. The actual measurement is a two step process. In the first step, the distance is measured in coarse resolution, and in the second step, the distance is measured in fine resolution. A first pulse train is transmitted using a transmit time base from the first radio transceiver. The first pulse train is received at a second radio transceiver. The second radio transceiver synchronizes its time base with the first pulse train before transmitting a second pulse train back to the first radio transceiver, which then synchronizes a receive time base with the second pulse train. The time delay between the transmit time base and the receive time base can then be determined.

Abstract: This invention relates to advanced RF support systems which utilize optical fibers or direct lasers to achieve RF transmission and reception of navigation signals from widely separated supporting sites. The functional goals of these systems are to support navigation, guidance, control, and survey systems. A RF supporting network according to the present invention comprises a master supporting site; a number of secondary supporting sites; and a network of optical RF link systems which links secondary supporting sites with the master supporting site. The stable clock, GPS signal generators, and receivers are located only at the master site, which is also the processing, command, and control center. A network architecture of the present invention will provide a low cost mean to users in need of precision navigation and time information. Furthermore, the present invention furnishes an advance means in determining the instantaneous velocity of GPS satellites with high accuracy.

Abstract: A golf distance indicator system provides measurement and display of the distance between a golfer and the pin on the green he is approaching. The system comprises a portable unit carried by the golfer and an target unit located on the pin. With the portable unit, the golfer selects the hole he is playing then activates the system. The portable unit sends a wireless coded message to an intended target unit. When a target unit receives a message, it analyzes the message to see if it should respond. If the target unit determines that it should respond, it sends a coded responding message to the portable unit. When the portable unit receives a responding message, it analyzes the responding message to see if the responding message originates from the intended target unit. If it does, the portable unit calculates a distance based on the elapsed time for the communications and the speed of the communications. The results are displayed on the portable unit.

Abstract: The present invention relates to a vehicle with a millimeter wave radar by which not only a distance and a relative velocity can be measured but also traffic information of other various kinds can be obtained.

Abstract: A distancing system comprising radio frequency transceivers and data processing circuits. The radio frequency transceivers allow data transmission via a high frequency radio signal. The transmission and receipt of these radio signals can be timed to estimate distance. But the data processing circuits operate at local clock frequencies, and one cannot be sure at what point a give radio frequency signal was received to a resolution greater than one-half cycle of the local clock signal. The data processing circuits periodically "skip" to resynchronize with incoming data streams. These skips occur at intervals corresponding to the frequency difference between the local clock frequencies. This frequency difference can be used to pinpoint fairly precisely when a given radio frequency signal was received in a previous half-cycle of the local clock.

Abstract: A phase difference measuring apparatus obtains a first receive signal by transmitting and receiving a to-be-measured material in a reference state and a second receive signal by transmitting and receiving a signal wave to and from that material in a measured state. The apparatus finds a reference phase difference .theta..sub.1 from the transmit wave and first receive signal and an apparent phase difference .theta..sub.2 ' from the transmit wave and second receive signal. The apparatus adds the apparent phase difference .theta..sub.2 ' to a product of the number of rotations, n, the apparent phase difference .theta..sub.2 ' passes through a given reference point and an angle of 360.degree. to find a true phase difference .theta..sub.2. The apparatus varies the number of rotations, n, to n+1 when the apparent phase difference .theta..sub.2 ', while being increased, passes through the reference point and that number of rotations, n, to n=n-1 when the apparent phase difference .theta..sub.

Abstract: An object in a storage area or moving vehicle is monitored by attaching an electronic tag to the object. An electronic device detects the presence of the object by communicating with the tag while the object is in storage or is being moved by the vehicle. The tags may also determine the location of an attached object and may reroute the object if it deviates from a given shipping schedule. A group of objects is monitored by two electronic tags, each attached to an object in the group. Each tag has circuitry for communicating information relating to an object in the group to a second tag. Each tag also includes a memory connected to the circuitry that is capable of storing the information, and a controller connected to the memory and the circuitry. A distance is measured by transmitting multiple symbols from one object to another object, having the symbols returned such that the symbols' measured round-trip times are not all identical, and calculating the distance using the measured round-trip times.

Abstract: A descriptor has the capabilities of providing state vectors to describe movable platforms, extended objects, information collecting and surveillance systems. An aggregator furnishes the descriptor with abilities to deliver the state vectors in dynamical situations of instabilities and chaos. The former comprises navigation antennas, optical RF link systems, and processing center for delivering the state vectors from received navigation RF signals. The latter comprises an RF delay loop for aggregating a train of RF signals into a single RF pulsed signal and means for outputting the pulsed signal for analysis. The aggregator has many applications. For instance, an aggregator is able to unscramble pseudo random signals with partial codes and to enhance the statistics of weak transient signals.

Abstract: A pulse-echo ranging system includes an improved target and a ranging device which emits pulses of electromagnetic radiation toward the target and receives pulses reflected from the target. The target is provided with a modulating mechanism for modulating the reflected pulses in a predetermined manner. The modulating mechanism allows the ranging device to distinguish pulses truly reflected from the target from noise and pulses reflected from objects other than the target. More specifically, the modulating mechanism may include a reflector which reflects the pulses at plural distances from the ranging device. The reflector may include a single reflective surface coupled to an oscillating vibrator, or plural reflective surfaces spaced at different locations from the ranging device.

Abstract: In accordance with the teachings of the present invention, a passive tracking system (30) and method of passively determining a range (R) to a remote signal emitter (10) elevated a distance above ground level (14) is provided. The method includes aligning an antenna (32) also elevated above ground level (14) substantially in the direction of the remote signal emitter (10). The antenna (32) receives combined radiated energy along a direct path (16) from the remote signal emitter (10) as well as radiated energy that has bounced off the ground level (14) and has been received along a bounce path (18) from the remote signal emitter (10). The range (R) to the remote signal emitter (10) is calculated based upon the combined direct and bounce path signals. Correlation processing and geometric triangulation is employed to calculate the range (R) to the remote signal emitter (10).

Abstract: A radio range finding system includes a radio range finder and a plurality of remote mobile transponders. The radio range finder transmits a signal modulated with an address code identifying a particular mobile transponder. When a mobile transponder receives the modulated signal M.sub.s transmitted by the radio range finder and the modulated signal has been modulated with an address code that corresponds to the address assigned to that mobile transponder, the mobile transponder transponds a return signal R.sub.s to the radio range finder. A receiver in the radio range finder conveys the received signal to a mixer which also receives an internal carrier signal identical to the modulated signal output by transmitter. The output of the mixer is then filtered and demodulated to yield an output signal proportional to the distance between the mobile transponder and the radio range finder.

Abstract: A phase difference measuring apparatus obtains a first receive signal by transmitting and receiving a to-be-measured material in a reference state and a second receive signal by transmitting and receiving a signal wave to and from that material in a measured state. The apparatus finds a reference phase difference .theta..sub.1 from the transmit wave and first receive signal and an apparent phase difference .theta..sub.2 ' from the transmit wave and second receive signal. The apparatus adds the apparent phase difference .theta..sub.2 ' to a product of the number of rotations, n, the apparent phase difference .theta..sub.2 ' passes through a given reference point and an angle of 360.degree. to find a true phase difference .theta..sub.2. The apparatus varies the number of rotations, n, to n+1 when the apparent phase difference .theta..sub.2 ', while being increased, passes through the reference point and that number of rotations, n, to n=n-1 when the apparent phase difference .theta..sub.

Abstract: A radio apparatus has a detector for detecting the electric field intensity of a test signal received from the other radio apparatus. The detector produces a mean value of the field intensity detected at a predetermined interval and outputs the resulting latest field intensity level signal to a memory circuit. Further, the detector sequentially compares the latest field intensity level signal with a plurality of intensity level signals stored in the memory circuit and thereby delivers a decision signal to a display. In response, the display displays a detailed positional relation between the two radio apparatuses.

Abstract: The spatial separation of an object from a reference location is monitored utilizing a proximity alarm system which comprises a transceiver station mounted on the object and a repeater station at the reference location. Both stations function to generate and transmit an encoded rf signal in a half-duplex manner, with the transceiver station initiating the process. In one embodiment of the system, a phase delay is measured between a remote signal originating at the transceiver station and a corresponding decoded timing signal received from the repeater station. Correlation of the phase delay with a reference value ascertains the distance between the stations and an alarm at the transceiver station is actuated when the distance exceeds a predetermined value. A second embodiment of the system employs a clock driven counter that is stopped when a predetermined multiple of decoded timing signals is received at the transceiver station in response to iterative transmissions therefrom.

Abstract: A range-finding system for measuring a target distance from a point of measurement to a target object, comprising a slave unit for calculating and indicating the target distance based on a waiting time from transmission of an interrogation signal to reception of a response signal and a master unit placed at a certain correction distance from the target object for transmitting the response signal when a delay time corresponding to the correction distance has elapsed from reception of the interrogation signal.

Abstract: A distance measuring system for measuring a distance between two objects has a transmitter assembly mounted on one of the two objects, for transmitting a plurality of electromagnetic waves having respective wavelengths different from each other at respective levels toward the other of the two objects, a receiver assembly mounted on the other object, for receiving the electromagnetic waves transmitted from the transmitting means, and a distance detector for detecting a ratio of levels at which at least one set of electromagnetic waves of the electromagnetic waves is received by the receiving means, as corresponding to a distance between the two objects, and determining the distance between the two objects from the ratio.

Abstract: A system and method for determining the range between a receiver of a radio frequency signal and a transmitter of the signal includes transmission of a ranging signal having a grossly timed trigger followed by a chirp waveform. In response to receipt of the leading edge of the grossly timed trigger, the receiver of the ranging signal generates a first reference chirp at about the same time as the expected time of receipt of the chirp waveform, and thereafter compares the two chirps to provide a time correction signal (it being known that when two identical chirp signals, one time delayed from the other, are mixed, the resulting signal will have a frequency proportional to the amount of delay between the two chirp signals.) The time correction signal is used to correct the timing of an outgoing corrected chirp that is to be used to determine range between the transmitter and receiver based on a time of arrival.

Abstract: A burst tone range processing system for determining the distance between a ranging station and a signal re-transmitting target device, generates a burst tone signal of finite duration and transmits the signal along a delay transmission path from the ranging station to the target and along a reference transmission path within the ranging station. The transmitted signals are received from the reference and delay paths and assigned time tags. The signals are then correlated and the time tags assigned to correlated signals are compared.

Abstract: A method for determination of positions of measurement objects from a number of measurements of the directions to the measurement objects made at separate points in time. During the initial measurements of the directions to the measurement objects, a number of assumed areas, within which the measurement objects are assumed to be located, are established along the direction to each measurement object. Subsequent measurements of the directions to the measurement objects are performed from at least two different measurement stations, which between the points in time are moved along different paths. In connection with the measurement of the directions to the measurement objects, the positions of the assumed areas are compared with the expected appearances of the measurement objects, and the assumed areas which exhibit the best correlation to the expected appearances of the corresponding measurement object are assumed to represent the positions of the measurement objects.

Abstract: A millimeter wave radar is placed on an aircraft and several radar targets are placed near a runway. The targets are discrete objects, each having a relatively localized radar cross section, a unique signature or a unique range bin, and a position which is accurately known. Targets should be spread over the length of the runway. Radar corner reflectors and active or passive repeaters are preferred. The locations of the radar targets with respect to the runway can be transmitted to the aircraft, or they can be stored on board. On board memory requirements can be reduced by requiring all airports to select one of only a few standard target placement patterns, or even only one. Targets are inexpensive, as are radars whose only precision requirement is in range, and not in azimuth or elevation angles. Range to at least three targets in the radar's field of view is all that is required for an on-board computer to determine the aircraft's location.

Abstract: An optical RF stereo systems includes multiple remote vehicles, a processing center, and optical RF link systems for transmitting RF signals from remote vehicles to the processing center and for transmitting command and control signals from the processing center to remote vehicles.

Abstract: A bistatic radar system includes a transmitting radar site; a receiving radar site; and an optical fiber RF link system for transmitting RF signals from the receiving site to the transmitting site and for transmitting command and control signals from the transmitting site to the receiving site.