摘要:
For detection of an electromagnetic signal, which is transmitted from a transmitting antenna (1), by means of at least two at least essentially identical receiving antennas (3, 4), whose sensitivity curve has a maximum (M) with falling flanks as well as sidelobes (SL) adjacent to it with sensitivity increased again at a reception angle symmetrically with respect to a basic alignment, with angle determination for an object which reflects the transmitted signal being carried out by the two receiving antennas (3, 4) by phase determination in an unambiguous interval (θu) whose boundaries (L) are predetermined by the distance (d) between the receiving antennas (3, 4), the distance (d) is chosen such that the boundaries (L) of the unambiguity area (θu) intersect the sidelobes (SL), and the reflective object is detected by means of vectorial addition of the signals from the receiving antennas (3, 4), after which the parameters R, v are determined.
摘要:
There is provided a radar system for detection of one or more objects. The radar system comprises a radar wave transmitter for simultaneously transmitting a CW radar signal and a FM-CW or MF radar signal, and a first radar wave receiver for receiving CW and FM-CW or MF radar signals, reflected from one or more objects present in a detection range of the radar system. The system may further comprise a first CW mixer for mixing CW transmission signals and reflected CW signals received by the first receiver, and a first FM-CW or MF mixer for mixing FM-CW or MF transmission signals and corresponding reflected FM-CW or MF signals received by the first receiver. The first CW mixer may be a mixer for mixing CW transmission signals and reflected CW signals received by the first receiver to produce one or more first CW beat signals, each first CW beat signal relating to the velocity of an object, and the first FM-CW or MF mixer may be a first FM-CW mixer for mixing FM-CW transmission signals and reflected FM-CW signals received by the first receiver to produce one or more first FM-CW beat signals relating to the distance to and the velocity of an object. The radar wave transmitter may be adapted for simultaneously transmitting a CW radar signal and a FM-CW radar signal, wherein the FM-CW radar signal is a ramp modulated signal. The radar system may further comprise several radar wave receivers for receiving reflected CW and FM-CW or MF radar signals, which receivers may be arranged along first and/or second receiver directions. The radar system may have means for detecting phase differences between corresponding reflected radar signals received by different radar wave receivers. There is further provided a method of radar detection of one or more objects, where the method comprises simultaneously transmitting a CW radar signal and a FM-CW or MF radar signal, and receiving, via a first radar receiver, reflected CW and FM-CW or MF radar signals reflected from one or more object present in a detection range of the radar system.
摘要:
A sensor front end is disclosed that is able to discriminate objects based on their range from the sensor and to derive bearing information therefrom. The sensor system includes a signal source for transmitting at least a first and a second sensor signal toward the object and receiving a first and a second reflected signal pulse therefrom, and for generating a first and second information signal based on the first and the second reflected signals, respectively; and an information processor programmed to receive the first and second information signal from the signal source and to determine bearing information for the object based on a phase difference between the first and second information signal. The information processor is preferably capable of generating sample points from the first and second information signal and calculating the bearing information using these sample points.
摘要:
An apparatus and method obtains positional information about one or more objects in a detection field. An array includes a transmitting element and a plurality of receiving elements. A truncated cross-correlation function may be applied to determine the interval between signals received by a plurality of the receiving elements, thereby to determine an angular position of an object. A warning zone may be defined and it is determined whether an object is within the warning zone. Also disclosed are techniques for stretching received signals, and techniques for obtaining positional information relating to an object using non-Doppler radar.
摘要:
For detection of an electromagnetic signal, which is transmitted from a transmitting antenna (2), by means of at least two at least essentially identical receiving antennas (3, 4), whose sensitivity curve has a maximum (M) with falling flanks as well as sidelobes (SL) adjacent to it with sensitivity increased again at a reception angle symmetrically with respect to a basic alignment, with angle determination for an object which reflects the transmitted signal being carried out by the two receiving antennas (3, 4) by phase determination in an unambiguity area (θu) whose boundaries (L) are predetermined by the distance (d) between the receiving antennas (3, 4), the distance (d) is chosen such that the boundaries (L) of the unambiguity area (θu) intersect the sidelobes (SL), and the reflective object is detected by means of vectorial addition of the signals from the receiving antennas (3, 4), after which the parameters R, v are determined.
摘要:
In an FM-CW radar apparatus which determines the azimuth to a target by a phase monopulse technique, an abnormal value resulting from the presence of multiple targets is detected. Three receiving antennas are arranged at spacings of 5λ/4 and 6λ/4, respectively, and it is determined whether the difference between the azimuth obtained from the combination of the receiving antennas spaced 5λ/4 apart and the azimuth obtained from the combination of the receiving antennas spaced 6λ/4 apart is smaller than a predetermined value or not; when the condition has been satisfied n times in succession, it is determined that the detected value is normal. On the other hand, if the condition has not been satisfied n times in succession, or if the difference is not smaller than the predetermined value, it is determined that the detected value is an abnormal value resulting from the presence of multiple targets.
摘要:
Apparatus for and methods of obtaining positional information about one or more objects in a detection field are disclosed. An array including a transmitting element and a plurality of receiving elements is provided. In one aspect a truncated cross-correlation function is applied to determine the interval between signals received by a plurality of the receiving elements, thereby to determine an angular position of an object. In another aspect a warning zone is defined and it is determined whether an object is within the warning zone. Also disclosed are techniques for stretching received signals, and techniques for obtaining positional information relating to an object using non-Doppler radar. Various implementations, modifications and applications of the techniques described are disclosed. Typical applications of the techniques described are with vehicles.
摘要:
Apparatus for and methods of obtaining positional information about one or more objects in a detection field are disclosed. An array including a transmitting element and a plurality of receiving elements is provided. In one aspect a truncated cross-correlation function is applied to determine the interval between signals received by a plurality of the receiving elements, thereby to determine an angular position of an object. In another aspect a warning zone is defined and it is determined whether an object is within the warning zone. Also disclosed are techniques for stretching received signals, and techniques for obtaining positional information relating to an object using non-Doppler radar. Various implementations, modifications and applications of the techniques described are disclosed. Typical applications of the techniques described are with vehicles.
摘要:
A radar highway motor vehicle guidance apparatus for guiding a land vehicle along a roadway using a backward looking and a forward looking, lateral position sensing, monopulse tracking radar guidance apparatus which transmits radar pulses backward and forward of the vehicle. The pulses are reflected back to the vehicle by a stripe distributed along the roadway. The stripe is a frequency selective surface which generates retro-reflective grating lobes at an operating frequency of the tracking radar. Operating the radar at two frequencies allows the radar to look at regions spaced at two different distances from the front of the vehicle. Highway related information may be encoded in the frequency selective surface by variations in the shape or dimensions of the frequency selective stripe morphology in order to modulate the reflected signal with highway information which is then also detected at the radar receiver. Target discrimination is enhanced by using pseudo random codes and matching antenna polarization with stripe polarization.
摘要:
In a radar system, which is used particularly in motor vehicles, the angle at which a detected radar target is located are determined by providing that echo signals of the radar target are picked up via at least two reception channels, and their amplitudes are standardized and compared with standardized values, stored in memory, of a duplex antenna graph of the radar system.