Abstract: A method for receiving a signal by using M multiple beams in a multi-antenna system including N antenna elements, is provided in and embodiment of the present application. The method includes setting, by M beams, a beam direction for the M beams and a modulation frequency for frequency modulation of a beam response and generating the M beams according to the beam direction and the modulation frequency set by the beams. M beam responses are generated for a receiving signal by using the generated M beams and the generated M beam responses are frequency modulated by using the modulation frequency set by the beams. The frequency-modulated M beam responses are band-pass filtered so as to separate the M beam responses and the separated M beam responses are respectively demodulated.

Abstract: A system and method are disclosed for providing broadband network access to mobile devices during air travel. The system transmits a first signal from a phased array antenna towards an airspace. The system also steers the phased array antenna towards an aircraft within the airspace based on a determined movement of the aircraft, a device signal generated by a mobile device aboard the aircraft, or a combination thereof. The system also determines a frequency shift associated with a return of the first signal from the aircraft. Still further, the system determines a second signal of a different frequency based on the frequency shift.

Abstract: An example folded radiation slot for short wall waveguide radiation is disclosed. In one aspect, the radiating structure includes a waveguide layer configured to propagate electromagnetic energy via a waveguide. The waveguide may have a height dimension and a width dimension. The radiating structure also includes a radiating layer coupled to the waveguide layer, such that the radiating layer is parallel to the height dimension of the waveguide. The radiating layer may include a radiating element. The radiating element may be a slot defined by an angular or curved path, and the radiating element may be coupled to the waveguide layer. The radiating element may have an effective length greater than the height dimension of waveguide, wherein the effective length is measured along the angular or curved path of the slot.

Abstract: Signals are maintained to be in phase at beam input ports of a Rotman lens antenna, and thus scanning at non-step antenna beam angles can be realized without increasing the number of input beams. The present invention provides an antenna beam scan module including: a Rotman lens that has plural beam ports and plural antenna ports; plural antenna elements; relative phase detectors that detect a relative phase difference between the signals input to the adjacent beam ports; phase shifters that offset the relative phase difference between the signals supplied to the adjacent beam ports on the basis of the relative phase difference detected by the relative phase detectors; and switches that select routes of the signals supplied to the beam ports through variable amplifiers, wherein the phase shifters are arranged on alternate routes through which the signals are supplied to the plural beam ports.

Abstract: A vehicle detection device includes: an antenna configured to sense electromagnetic waves; an image generation unit configured to generate a radio wave image; a road surface region detection unit configured to detect a road surface region in the radio wave image; a symmetry axis setting unit configured to set a first symmetry axis at a part of the boundary of the road surface region; a road surface reflection region setting unit configured to set a horizontal central line at a center of the radio wave image and set a road surface reflection region between the central line and the first symmetry axis; and a vehicle detection unit configured to compare the waveform of pixel outputs in the road surface reflection region with the waveform of pixel outputs in the road surface region and to detect the road surface reflection region as a vehicle.

Abstract: A transmission system that can continue communication even if a tracking error exists and to reduce interference on other transponders when transmitting a video and audio between an endstation facility and another endstation facility via a transponder mounted on communications satellite. This transmission system includes a tracking antenna that tracks a transponder, a tracking error calculation circuit that obtains a tracking error in a tracking operation of the tracking antenna, a transmission level control circuit that obtains a transmission level of a signal in response to the tracking error, and a transmitter that transmits the signal at the obtained signal level via the tracking antenna to the transponder of the communication target.

Abstract: A feed network for an antenna subarray includes a first feed arrangement having an sum output, a second feed arrangement having an delta output, a fixed attenuator having a first port and a second port, the first port connected to the delta output of the second feed arrangement, a first power divider/combiner having a first and second port and a third port; the first port connected to the second port of the fixed attenuator, a variable phase shifter having a first port and a second port, the first port connected to the second port of the power divider/combiner, a variable attenuator having a first port and a second port, the first port connected to the second port of the variable phase shifter, a second power divider/combiner having a first and second port and a third port; the first port connected to the second port of the fixed attenuator, a first circulator having a first port, a second port and a third port, the first port connected to the sum output of the first feed arrangement, and a third power divide

Abstract: Provided is a location information management method including: step in which a mobile station acquires information on a second radio base station transmitted via a common control channel from the second radio base station while communication is performed with a first radio base station; step for transmitting the information to a radio control device; step in which the radio control device transmits a measurement instruction to the mobile station and the first radio base station if the information on the second radio base station is received; and step for deciding and managing the location information on the mobile station in accordance with the measurement result.

Abstract: Provided herein is a compact and economical direction finding antenna using a mono-pulse antenna system, where a plurality of antenna elements are disposed in a circular array. The directional antennas may be formed by any type of antenna element, including a patch or reflector. The antenna beams of the directional antenna elements overlap, so that from any azimuthal direction, the point is covered by more than one antenna beam. Signals from each pair of adjacent antenna elements of the circular array are processed in order to determine the angle of arrival of a received signal.

Abstract: An exemplary radio-based navigation system uses a small multimode direction-finding antenna and a direction-finding receiver capable of determining platform position, velocity, attitude, and time while simultaneously providing protection against narrowband and broadband sources of interference. Global Navigation Satellite System (GNSS) signals such as those from the Global Positioning System (GPS) provide attitude measurements with a compact multimode direction-finding antenna (e.g., a small two-arm spiral with improved angle-of-arrival performance over the entire hemisphere enhanced through the use of a conductive vertical extension of the antenna ground plane about the antenna perimeter and/or conductive posts placed evenly around the antenna perimeter) which provides simultaneous protection against jammers. The multimode spiral may be treated as an array of rotationally-symmetric antenna elements.

Abstract: A system and method for a single site beacon transceiver including an omni-directional transceiver, a plurality of directional receiving antennas for receiving a signal, and a digital receiver for processing the signal to determine an azimuth to the source of the received signal. The digital receiver includes a plurality of receiver channels that are calibrated periodically and at least one processor that estimates a coarse signal azimuth for the signal by calculating an amplitude monopulse ratio for the signal using the two directional receiving antennas receiving the highest amplitude signal, and estimates a final signal azimuth for the signal using an interferometer baseline between the two directional receiving antennas or, alternately, subtracts the complex ratio of the measurements from the complex ratio of the antenna array RF model to determine the angle corresponding to the minimum of the absolute value of the difference.

Abstract: Systems and methods for tracking a remote source and monitoring and controlling the angular orientation of an antenna array, including a first antenna portion and a second antenna portion, are provided, including a sum-difference structure coupled to a first output of the first antenna portion and a second output of the second antenna portion, where the sum-difference structure provides both a sum power signal and a difference power signal, and where both the sum power signal and the difference power signal have associated RSSI values generated by an RSSI circuit. Systems and methods provided herein further include a sum-delta processor configured to utilize the RSSI values to generate an off-bore-sight angle of the antenna array relative to a position of a transmitting radiofrequency signal source.

Abstract: An antenna system and electronic scanning method that employs feed subarray electronic offset beam scanning. The system includes a feed element containing an array of electronic transmitting/receiving elements. The system further includes a reflector for reflecting signals received from the feed element to a target region, and for reflecting signals received from a target region to the feed element. Electronic beam scanning is achieved by activating and deactivating in turn subarrays within the array of transmitting/receiving elements of the feed element.

Abstract: Systems and methods are provided for extracting relative signal parameters representing two closely spaced targets from monopulse scan data. A maximum quadrature angle value from the scan data is compared with a threshold quadrature value representing a noise level. A linear polynomial model is utilized if the maximum quadrature angle exceeds the threshold value. The linear polynomial model fits a function of the azimuth angle values and quadrature angle values to a linear function of an exponential parameter derived from the boresight angles to produce polynomial coefficients and determines the relative signal parameters from the polynomial coefficients. A cubic polynomial model is utilized if the maximum quadrature angle fails to exceed the threshold value. The cubic polynomial model fits azimuth angle values to a cubic function of corresponding boresight angles to produce a set of polynomial coefficients and determines the relative signal parameters from the set of polynomial coefficients.

Abstract: A low cost radar system that employs monopulse beamforming to detect objects in the road-way both in elevation and azimuth. In one non-limiting embodiment, a beamforming receiver architecture includes a first beamforming device and a plurality of antennas coupled to the first beamforming device, and a second beamforming device and a plurality of antennas coupled to the second beamforming device. The first and second beamforming devices are oriented 90° relative to each other so that the receive beams provided by the first beamforming device detect objects in azimuth and the receive beams provided by the second beamforming device detect objects in elevation. A first switch is provided to selectively couple the sum pattern signal from the first and second beamforming devices to one output line, and a second switch is provided to selectively couple the difference pattern signals from the first and second beamforming devices to another output line.

Abstract: A method for mitigating multipath impacts on azimuth accuracy in a monopulse interrogator is accomplished by calculating samples of monopulse ratio for samples of antenna boresight angles based on data received from an interrogation of a target. Samples of traditional target azimuth from the samples of monopulse ratio are calculated. A mean of the samples of traditional target azimuth is calculated. An alternative target azimuth from the samples of monopulse ratio is calculated. Whether a multipath signal exists is determined from observing a standard deviation of the samples of traditional target azimuth, and using the mean of the traditional target azimuth if a multipath signal does not exist and using the alternative target azimuth if a multipath signal does exist.

Abstract: A method includes determining if a dynamics requirement for an antenna positioner is exceeded, and employing a combination of mechanical and electronic beam steering techniques to steer a single antenna beam if the dynamics requirement is exceeded.

Abstract: A system and method for using a phased array antenna to concurrently receive an RF signal transmitted by a remote transmitter, to determine the angular location of the remote transmitter using the transmitted signal, and to use that angular location to direct a transmit antenna to transmit information in the direction of the transmitter is disclosed.

Abstract: A system and method for using a phased array antenna to concurrently receive an RF signal transmitted by a remote transmitter, to determine the angular location of the remote transmitter using the transmitted signal, and to use that angular location to direct a transmit antenna to transmit information in the direction of the transmitter is disclosed.

Abstract: Tracking of collocated satellites is accomplished by providing a single tracking antenna having a tracking feed and combiner which receives a first satellite signal. A first pointing error signal is extracted from the tracking feed based on the first satellite signal and the antenna is steered to a pointing angle to minimize the first pointing error signal. A second satellite signal is received and a second pointing error signal is extracted from the tracking feed based on the second satellite signal. An offset angle for the second satellite is then calculated from the second pointing error signal relative to the pointing angle of the antenna. Orbit estimation and can then be accomplished for the second satellite based on the offset angle directly or by conversion to an absolute angle.

Abstract: A location determination device (104) is worn on a user's head to facilitate searching and tracking for another individual carrying a portable radio (102) as well as locating exit routes. At least two antennas (108), a monopulse receiver (110) and a display are integrated into the location determination device (104). Location determination device (104) scans for an incoming signal (106) from the portable device (102) and coverts the signal into angular location data. The location data and egress information are displayed to the peripheral vision of the user of the location determination device (104).

Abstract: The present invention relates to a signal combining apparatus of the active phase array antenna. The signal combining apparatus includes a plurality of signal distributors for receiving a signal from an antenna array element located at boundary between sub antenna arrays and distributing the signal to the sub antenna arrays, which include the antenna array element; and a plurality of signal combiners for combining the signal from a plurality of antenna elements and the signal distributors in corresponding sub antenna array. The present invention can prevent degrade a performance caused by sudden phase difference and can effectively receive tracing signal by passing a signal of antenna element located at boundary between sub arrays antenna to both signal combiners corresponding to both of sub antenna arrays.

Abstract: Improved punch-through performance is provided for applications such as sum and difference mode processing for IFF and other applications. With an array including a row of elements, difference sidelobe levels are increased relative to sum sidelobe levels by independently controlling relative signal levels of difference mode signals provided from signals received by central elements of the array. By processing signals from central elements independently from processing of signals from outer elements of the array, difference mode signals derived from the central elements may be employed at higher signal levels in order to raise difference mode sidelobe levels to improve punch-through performance. Antenna systems and methods are described.

Abstract: In order in simple manner to switchably cover a wide angle in sectors using an antenna array with broad main lobe, an antenna elements are so arranged, that the elements can be individually selected, so that some elements of the array can be operated in-phase and other elements operated in phase-opposition relative to each other. In order to determine the entry direction of a received signal, it is possible to operate the antenna array with non-symmetric antenna diagram, or however also to additively influence the symmetry of antenna characteristic by the use of a supplemental receiver element.

Abstract: A system for ascertaining angle of arrival of an electromagnetic signal having at least one signal characteristic indicating a first state or a second state includes: (a) a plurality of n antenna elements intersecting a common axis and cooperating to establish 2n sectors; each respective sector being defined by two antenna elements and the axis; the signal characteristic indicating the first state on a first side of each antenna element and indicating the second state on a second side of each antenna element; combinations of the signal characteristics in each respective sector uniquely identifying the respective sector; and (b) an evaluation apparatus coupled with the antenna elements and employing the state of the signal characteristic sensed by each of the antenna elements to effect ascertaining angle of arrival to a resolution of at least one respective sector.

Abstract: Method and apparatus for high resolution tracking via mono-pulse beam-forming in a communication system in which the capacity and range of mobile or fixed wireless communication base stations are improved by implementing a single or multiple antenna beam per signal path. Adaptive beam-forming based on up-link direction-of arrival estimation can be performed without using the above-mentioned computationally intensive techniques.

Abstract: The invention relates to a base station for a radio communications network. In order to be able to enhance the resolution for a direction of arrival estimation, the base station comprises: a first phasing network (31) for forming beams (B1-B4) for fixed reception angles; a second phasing network (33) for co-phasing and summing the signals of at least two neighbouring beams (B2, B3), thus forming a beam (B2-3) for a reception angle in-between at least those two neighbouring beams (B2, B3), and for scaling each resulting beam (B2-3) with a predetermined factor; and means for estimating the direction of arrival in the uplink from the beams (B1-B4, B2-3) provided by the first and the second phasing network (31, 33). The invention equally relates to a corresponding method and to a base station module comprising such a first and second phasing network.

Abstract: Antennas having a circular array of radiating elements are arranged to enable continuous 360 degree scanning of a sum and difference beam pattern. With a 108 element circular array, a sub array of 27 contiguous elements may be step scanned to 108 positions while maintaining sum and difference antenna patterns. Each scan step may require only two switch adjustments, one to initiate excitation of a contiguous leading element and terminate excitation of the trailing element, and the other to change coupling of a middle element from a divided power port of a left power divider to such a port of a right power divider. Configurations using sub arrays whose element complement is not evenly divisible into the total number of array elements, using sub arrays consisting of an odd number of radiating elements, or employing minimized feed network complexity are disclosed.

Abstract: A system for ascertaining angle of arrival of an electromagnetic signal having at least one signal characteristic indicating a first state or a second state includes: (a) a plurality of n antenna elements intersecting a common axis and cooperating to establish 2n sectors; each respective sector being defined by two antenna elements and the axis; the signal characteristic indicating the first state on a first side of each antenna element and indicating the second state on a second side of each antenna element; combinations of the signal characteristics in each respective sector uniquely identifying the respective sector; and (b) an evaluation apparatus coupled with the antenna elements and employing the state of the signal characteristic sensed by each of the antenna elements to effect ascertaining angle of arrival to a resolution of at least one respective sector.

Abstract: A detection apparatus is provided to detect the direction of arrival and the position of an emission source of radio wave with high accuracy.

Abstract: Method and apparatus for high resolution tracking via mono-pulse beam-forming in a communication system in which the capacity and range of mobile or fixed wireless communication base stations are improved by implementing a single or multiple antenna beam per signal path. Adaptive beam-forming based on up-link direction-of arrival estimation can be performed without using the above-mentioned computationally intensive techniques.

Abstract: A method of controlling a satellite communication system, a timing unit, and a control unit of a timing unit. The method comprises dividing the coverage area of the satellite communication system into one or several geographical areas; positioning one or several timing units in at least one geographical area; determining which of the satellites of the satellite communication system are visible in each particular geographical area; controlling the timing unit with a control unit, in order to minimize the time difference within the system, to listen to one or several satellites visible in each particular geographical area, the signals received from the satellites by the timing unit fulfilling a predetermined condition; synchronizing a predetermined number of geographical areas with each other by means of the control unit of the system such that the time difference within the system is minimized in a predetermined combination area of geographical areas.

Abstract: A monopulse phased array system comprises antenna elements with T/R modules controlled a beam steering computer. The space in which the antenna elements are arranged is divided into quadrants which are defined relative to the main axis of the radar beam. From the signals received by means of separate antenna elements, sum signals and first and second angle difference signals are derived: After combination of these signals delivered by the T/R modules, control signals are obtained for resteering the radar beam generated under the control of the computer mentioned. Each of the T/R modules is provided with two 180° phase shifters for determining the angle difference signals.

Abstract: A system and method for RF autotracking multiple antennas (preferably located on a spacecraft) to compensate for disturbances experienced by the antennas. The system and method estimate high frequency errors associated with all of the antennas. The high frequency errors may be estimated using a currently selected antenna and a high-pass filter. The high frequency errors may be estimated using a sensor mounted on the spacecraft, such as a gyro or star tracker, or may be estimated using information, such as planned thruster firings, for example, from a spacecraft attitude control system. Alternatively, the high frequency information may be estimated using any combination of data from these sources. Low frequency errors are estimated using measurements from each selected antenna. The algorithm implemented in the present invention explicitly accounts for the frequency content of each disturbance source.

Abstract: In a radar system, sampled aperture data are received from an antenna array. The sampled aperture data include data that do not correspond to echo returns from a beam transmitted by the antenna. A covariance matrix is generating using the sampled aperture data. An eigenvalue decomposition is performed on the covariance matrix. A direction of arrival is determined from which at least one jammer is transmitting a signal included in the sampled aperture data, based on the eigenvalue decomposition.

Abstract: A pair of patch antennas are used to form a null slit antenna pattern for receiving GPS signals from at least three GPS satellites functioning as pseudo stars for spin rate and spin axis attitude determination for a spinning space vehicle in an earth orbit below the GPS satellites.

Abstract: A radar monopulse signal receiving system according to an aspect of the invention provides sum (&Sgr;) and a single difference (&Dgr;) beam outputs from the beamformer. This is accomplished by encoding the information relating to the azimuth and elevation difference beams onto a single complex number. By comparison with some prior-art arrangements, the number of channels required for processing the signals is reduced. Near the end of the monopulse processing, the quotient is taken of complex number divided by the sum beam information, which directly produces a complex monopulse ratio m=mA+jmE. The azimuth and elevation monopulse ratios are represented by mA and mE, respectively.

Abstract: An antenna array system with dynamic signal routing to a set of receivers. A monopulse electronically scanned antenna (ESA) has a plurality of antenna elements divided into subarrays. ESA beam steering phase shifters are associated with the respective subarrays of antenna elements, such that the output signals from the respective antenna elements associated with the respective quadrants are phase shifted and summed to provide respective subarray signals. A monopulse network responsive to the subarray signals provides monopulse outputs to a set of receivers. A beam steering controller provides phase shift commands to the ESA phase shifters to set the phase shift associated with the respective phase shifters of the subarrays. The controller commands the ESA phase shifters to modulate the phase shift of selected quadrants.

Abstract: A null slit antenna pattern receives GPS signals from at least three GPS satellites functioning as pseudo stars for spin rate and spin axis attitude determination of a spinning space vehicle in an earth orbit below the GPS satellites.

Abstract: A control system for maximizing performance of an electronically scanned, mechanically augmented phased array (MAPA) antenna. In one preferred form, the control system forms a closed loop system which monitors a signal quality of the received signal from a primary signal source such as a primary satellite, and generates motor control signals for controlling a motor used to rotate the MAPA antenna about an axis so as to point the antenna at least slightly away from the primary signal source while electronically steering the antenna to track the primary signal source. The MAPA antenna is positioned so as to maximize the carrier-to-noise-plus-interference (CNI) ratio, and thus minimize the influence of interfering signal sources operating within a coverage region of the MAPA antenna.

Abstract: A method and apparatus are provided for determining whether a signal received the main channel (2) of an antenna (1) was incident on the antenna (1) in a direction corresponding to a high gain main lobe. A sidelobe suppression signal is generated from signals received from a other channels at least some of which are derived from elements where output generates the main channel, the signal being categorized as originating from a direction corresponding to the high gain main lobe of the main channel by comparing the value of the signal received on the main channel with that of sidelobe suppression signal.

Abstract: An object of the present invention is to provide a selective level measuring apparatus with wider dynamic range of effective value detection, compared with the range by a conventional one. The apparatus according to the present invention comprises a gain control means arranged before an effective value detection section for varying a gain by a control voltage, so that a signal level inputted into the effective value detection section may be kept to be constant level by the gain control means, and the signal level of the signal to be measured is measured and indicated through the control voltage. Performing such operations allows the selective level measuring apparatus for the effective value detection to secure a dynamic range defined by a variable quantity of the gain control means. Accordingly, the present invention provides the wider dynamic range of the effective value detection comparing with that by the conventional one.

Abstract: A technique is described which makes novel use of monopulse data to augment the normal CFAR detection processing by incorporating monopulse data in a computationally simple way into the detection decision process such that off-axis signals which are of sufficient strength to pass a CFAR detection threshold are effectively rejected by a second detection threshold. The signal compared to the second detection threshold is formed from all of the monopulse channels. Detection processing is thus a two step process, incorporating not only the information contained in the magnitude of the Sum channel, but information contained in all of the monopulse channels.

Abstract: A radar apparatus comprising: a receiving antenna having an array antenna in which a plurality of antenna elements are arrayed in a horizontal direction; and a signal processing section for carrying out recognition of a target existing in a predetermined horizontal bearing range from receive signals received by the receiving antenna, by electrically carrying out horizontal scanning of an antenna pattern of the receiving antenna, wherein at least one of the antenna elements is placed with a shift in a vertical direction, and wherein the signal processing section detects an altitudinal bearing of the target by a monopulse method by use of a receive signal from the antenna element with the shift in the vertical direction.

Abstract: A system and method for eliminating pointing error in a beacon tracking system due to uncontrolled differences in passive loss or in amplification of the separate signals involved in creating a pilot signal. A locally generated reference signal (30) is radiated onto a set of feed horns (14), at least three (20, 22, 24) of which are used to track a pilot signal (18). The reference signal (30) is detected and used in an automatic gain control feedback loop (44, 46, 48) to maintain equal gain on the separate feed horn channels. The equalized signal is processed (62) to produce precision tracking signals.

Abstract: A monopulse source for a focal feed antenna including at least two waveguides machined in a metal flange supporting a microwave transmission and reception circuit of the antenna, and a dielectric substrate on the metal flange. Also included is a microwave short-circuit having an opening with a smaller dimension than a dimension of a respective waveguide. The microwave short-circuit is mounted on the dielectric substrate such that an axis of the microwave short-circuit coincides with an axis of the respective waveguide. Further, a transition positioned on the dielectric substrate and within the opening of the microwave short-circuit is configured to couple the respective waveguide.

Abstract: A system and method for estimating azimuth angle, elevation angle and signal detection and which includes an antenna system having a plurality of elements, each element receiving a different concurrent portion of an incoming analog signal having a real and an imaginary portion. A converter is provided for each antenna element for converting each analog signal to digital form. A processor is provide for multiplying the sum of the real parts of the signals from a first group of the elements with the conjugate of the sum of the remainder of the elements to provided an estimated azimuth, elevation of signal detection measurement. In the case of a four element antenna, AzEst=Angle((A+B)*(C+D)Conjugate))=(x.sub.A +iy.sub.A +x.sub.B +iy.sub.B)*(x.sub.C -iy.sub.C +x.sub.D -iy.sub.D), ElEst=Angle((A+D)*(B+C)Conjugate))=(x.sub.A +iy.sub.A +x.sub.D +iy.sub.D)*(x.sub.B -iy.sub.B +x.sub.C -iy.sub.C) and Magnitude ((A+B*(C+D)Conjugate)) or Magnitude ((A+D*(B+C)Conjugate)).

Abstract: An antenna array for identifying aircrafts operating in a region of interest. The antenna includes a beam forming means and an antenna means. The beam forming means receives, processes and routes a sum and difference beam pattern to the antenna means. The antenna means transmits the sum and difference beam patterns to five separate beam locations in space.

Abstract: An antenna having multiple antenna elements that are selectively activated performs an initial acquisition of a satellite signal by activating only a few of the antenna elements. This results in a broad beam width and increases the likelihood of detecting the signal from the satellite. When the satellite signal is initially detected, the system increases the number of active elements to narrow the beam width. The system incrementally increases the number of active antenna elements until the detected signal from the satellite exceeds a predetermined threshold. At that point, the location of the satellite may be precisely determined and all antenna elements activated to lock onto the satellite signal. If the antenna loses acquisition of the satellite signal, the reverse process may be implemented whereby some elements are selectively deactivated to broaden the beam width of the antenna in an effort to reacquire the satellite signal.

Abstract: A satellite tracking method for a vehicle-mounted receiving antenna system to determine the orientations of satellites dependent upon the moving direction of a moving body such as an automobile associated with the attitude control of an antenna which is mounted on the moving body for the purpose of receiving satellite broadcasting signal, the method including an initial mode, a maximum value search mode, a normal tracking mode, an error correction mode, a signal blocking mode and a rainfall mode.