Abstract: An attitude determination system and method employs first and second baseline determinations comparing the relative phase of carrier signals received from GPS satellites. Attitude determinations include determination of roll, pitch and azimuth of ships, aircraft, vehicles and other devices.

Abstract: A resilient body electrical connector is shaped and dimensioned to define at least one mating interface parallel to a longitudinal axis. A first plurality of electrical conductors is disposed with each having a portion embedded in the connector body, and each having a respective contact point protruding from the connector body, the contact points being disposed in a contact plane parallel to the mating interface. A receptacle is configured to slidably receive the mating interface along a complementary receiving interface. A second corresponding plurality of electrical conductors are embedded in the receptacle and define respective contact faces disposed along the complementary receiving interface. The connector and receptacle are shaped and dimensioned such that they define a guide means, the guide means being configured to guide the connector as it is inserted longitudinally into the receptacle such that the contact surfaces slidably receive the contact points.

Abstract: Method and apparatus for monitoring the present location of an emergency or general serviceperson, such as a firefighter or a hazardous materials spill clean-up specialist, assigned to perform emergency services at a designated site. The site diameter can be as small as a few meters or as large as several kilometers. The serviceperson's present location can be checked at selected time intervals with time periods ranging from a few hundred milliseconds to thousands of seconds, as desired. The serviceperson wears or carries a location-determining ("LD") unit that receives electromagnetic signals that contain information allowing determination of the present location of the LD unit, and thus of the serviceperson, from three or more signal sources.

Abstract: A method for monitoring the movement of a vehicle along a selected route R to determine whether the vehicle is (i) adhering to that route and/or (ii) adhering to a selected time schedule along that route. Adherence to the route R requires that the vehicle travel within a corridor of selected positive width that surrounds a path defining the route R. Adherence to the time schedule requires that the vehicle move past one or more specified locations along or adjacent to the route R within a specified time interval. The method provides an electronic map with a visually perceptible display that indicates the present location of the vehicle and allows implementation of a snap-to-route command that displays the location on the route R that is closest to the present location of the vehicle.

Abstract: The present invention relates to the new W code enhanced GPS receiver which allows to receive and demodulate the L1 and L2 satellite signals encrypted with the unknown Y code. No assumptions are made about the timing or the structure of the unknown Y code. The signal-to noise ration is not compromised in comparison with the reception of the L1 and L2 signals without code encryption.

Abstract: An improved navigation satellite receiver with a digital channel processor including a triple carrier mixer with an early carrier mixer, a punctual carrier mixer and a late carrier mixer all connected to receive I and Q sample outputs from an IF downconverter. A triple carrier numeric controlled oscillator (NCO) includes an early carrier NCO, a punctual carrier NCO and a late carrier NCO for synthesizing three independent local carrier frequency outputs that are separated in phase from one another. A triple code mixer connects to the triple carrier mixer and comprises an inphase early-carrier early-code mixer, an inphase punctual-carrier punctual-code mixer, an inphase late-carrier late-code mixer, a quadrature early-carrier early-code mixer, a quadrature punctual-carrier punctual-code mixer, and a quadrature late-carrier late-code mixer with corresponding outputs for each mixer.

Abstract: A Personal Digital Location Apparatus for displaying a geographical location as an icon on a map. The apparatus includes a GPS Smart Antenna for determining the geographical location, a personal computing device including a display, a processing system including a standard software operating system such as DOS, Windows, Macintosh, or Geoworks, and a map application program capable of running in the operating system. The GPS Smart Antenna includes an internal battery and a power sensor for sensing the connection of an external power source. The GPS Smart Antenna receives power from the external power source when the power sensor senses that the external power source is connected and receives power from the internal battery when the power sensor senses that the external power source is not connected.

Abstract: A method for compensating for the differences in time varying signals S(t;R;S) received and processed by two signal receiver/processors (R.sub.2 and R.sub.3), located at the same site, from two signal sources (S.sub.2 and S.sub.3) that are spaced apart from the receiver/processors. A receiver/processor (R.sub.1) is chosen as a baseline, and double difference signals DD(t;R.sub.1 ;R.sub.2 ;S.sub.2 ;S.sub.3)=S(t;R.sub.1 ;S.sub.2)-S(t;R.sub.1 ;S.sub.3)-S(t;R.sub.2 ;S.sub.2)+S(t;R.sub.2 ;S.sub.3) and DD(t;R.sub.1 ;R.sub.3 ;S.sub.2 ;S.sub.3)=S(t;R.sub.1 ;S.sub.2)-S(t;R.sub.1 ;S.sub.3)-S(t;R.sub.3 ;S.sub.2)+S(t;R.sub.3 ;S.sub.3) are formed. The respective time averages DD(R.sub.1 ;R.sub.2 ;S.sub.2 ;S.sub.3).sub.avg and DD(R.sub.1 ;R.sub.3 ;S.sub.2 ;S.sub.3).sub.avg of these two double difference signals are formed, using a time interval of length T lying in a preferred range given by 120 sec.ltoreq.T.ltoreq.1800 sec. First difference signals, DDC(t;R.sub.1 ;R.sub.2 ;S.sub.2 ;S.sub.3)=DD(t;R.sub.1 ;R.sub.2 ;S.sub.

Abstract: Integrated antenna apparatus for determination of the location of an observer and/or of the time of observation by use of a GPS or a GLONASS or other Satellite Positioning System that uses differential corrections of the pseudorange, the location and/or the observation time. The apparatus includes an antenna module and a display module, connected by a communication link. In one embodiment, the antenna module includes: a GPS antenna to receive the GPS signals; a signal frequency downconverter; a Differential GPS (DGPS) radiowave signal antenna and receiver to receive GPS correction information; a GPS/DGPS signal processor to receive the GPS antenna and DGPS antenna output signals and to determine at least one of (i) the present GPS antenna location, as corrected by the DGPS signals, and (ii) the observation time of such location; and a communication link to communicate GPS processor output signals to the display unit.

Abstract: A system and method for optimizing data transmission and storage of minimal sets of position, time, and residual information required for differential global positioning involving at least two GPS receiving stations, one of which may be stationary and at least one of which is mobile, with increased accuracy and compactness. The method includes sending or storing minimal and enhanced combinations of information. If the indicated values are stored rather than immediately transmitted, they may be retrieved for subsequent combination with values established at another station which may be stationary or mobile. The invention relates particularly to the enablement and performance of compacted storage and transmission of position-oriented and residual information for GPS systems and methods.

Abstract: An antenna system embodiment of the present invention comprises a curved dipole antenna stood off at its center by a printed circuit board assembly containing a pre-amplifier. The curved dipole antenna is implemented with a single-sided flexible circuit and is anchored at its four free ends to a sheet metal base for a groundplane. The printed circuit board assembly containing the predetermined amplifier is fixed perpendicular to the sheet metal base and has a tab that engages a slot in the center of the single-sided flexible circuit for electrical connection of a pair of orthogonal dipoles patterned on one side of the flexible circuit.

Abstract: Apparatus for providing accurate local time for one or more timed devices that depend on such time for operation. In one embodiment, a Satellite Positioning System (SATPS), such as GPS or GLONASS, provides the time signal information. In another embodiment, the time signal information is provided by telecommunication means, such as a telephone, cellular telephone or similar apparatus. The local time signal is distributed by a time signal distribution module to one or more timed devices by a wire or transmission line, by radio waves, or by direct contact with an input terminal of a timed device. The time signal distribution module may be a single station, a master station for a system of timed devices, or a portable module that can be moved from one timed device to the next.

Abstract: A system embodiment of the present invention comprises a fixed and a roving pair of four-observable GPS receivers and a communication link between them for double differencing code and carrier measurements. Carrier phase integer ambiguities are resolved efficiently by searching the simultaneous narrow-lane intersections of both the L1 and L2 wave fronts propagated by the GPS satellites being tracked. External constraint information, such as elevation, is additionally used to speed up integer ambiguity resolution. Data between the reference station and the rover is communicated in compressed form at a regular interval, e.g., once a second at each epoch, and demi-measurements of carrier phase are obtained more frequently, e.g., ten times a second, and used to propagate solutions between epochs.

Abstract: Apparatus and method for eliminating the time delay variation associated with the satellite signal propagating within an antenna for a GPS receiver (or GLONASS receiver). The antenna is an n-point symmetrical feed double-frequency feed antenna which has the reduced electrical center error ellipsoid as compared with the single point antenna. The angular dependence of the time delay variation on the azimuth and the angle of elevation of the incoming satellite signal is reduced in case of n-feed point symmetrical antenna. The GPS receiver with n-point antenna can be used for differential GPS, both static and dynamic, and for absolute GPS positioning.

Abstract: A surveyor range pole, for example, equipped with a GPS receiver and antenna mounted at the top end, a battery mounted at the bottom end to better balance the pole, a tilt sensor and a direction sensor. The tilt sensor and direction sensor provide information about the vector that lies between the top and the bottom points of the range pole. The GPS receiver computes the position of the top end of the range pole from GPS satellite signals received by the GPS at the top end, and then computes the position of the bottom end of the range pole with the vector information. A variable length, telescoping range pole includes a linear transducer for automatically measuring the overall length of the range pole and contributing that length information to the vector calculation.

Abstract: Methods for provision of a sequence of timing signals for one or a plurality of microprocessors, microprocessor peripheral devices or other timing-controlled instruments ("users"), using timing signals determined from a Satellite Positioning System (SPS), such as GPS or GLONASS. In a first embodiment, one or a plurality of users is individually provided with SPS signal antennas and receiver/processors, and timing signals are optionally individually for each user. The timing signals can be periodic, for example, a One-Pulse-Per-Second signal for fine corrections of high frequency timing signals issued by an internal or external clock. The timing signals can also be substantially non-periodic. The timing signals may also be used to determine the time at which selected events occur, such as issuance of interrupt commands in, or directed to, a microprocessor.

Abstract: An embodiment of the present invention combines, on a single integrated circuit, an eight channel GPS receiver, a 68330-type microprocessor, a 68681-type DUART serial communications controller, an analog-to-digital converter, a real-time clock, a random access memory and a boot read-only memory. A system integration module and inter-module bus allow tri-state control of the microprocessor such that a commercially available 68332-type emulator may be used for software development.

Abstract: A GPS emergency rescue network comprising at least one GPS receiver and L2-frequency transmitter combination for a target, and a GPS receiver able to tune the L2 frequency transmissions of the target's transceiver. A constellation of orbiting GPS satellites transmit their range information on two carrier frequencies, L1 and L2, and are differentiated from the survivor's L2-frequency transmissions by unique pseudo-random number codes in the spread spectrum code multiple access scheme that is otherwise conventional.

Abstract: A method for enhancing the accuracy of location coordinates and/or clock bias computed for a mobile user station that is part of a Satellite Positioning System (SATPS), such as GPS or GLONASS. A reference SATPS station is provided with known location coordinates, and pseudoranges PR(t) and pseudorange corrections .DELTA.PR(t) for the reference station are computed as in a conventional differential GPS approach. A matrix equation H(t) .DELTA.W(t)=.DELTA.PR(t) relates the corrections for the spatial location coordinates and clock bias at the mobile station (or at the reference station) to the pseudorange correction values at that station, where H is an M.times.N matrix (M.ltoreq.N; N=3 or 4) with known entries. Each of the N rows of the matrix H has M entries and forms a row vector, and these row vectors are linearly independent in an M-dimensional vector space. These row vectors span an N-dimensional vector space.

Abstract: A method for directing a vehicle from a fleet of N vehicles, numbered n=1, 2, . . . , N(N.gtoreq.2), to respond to a call for assistance received at a central processing station that communicates with a communications unit on each of these vehicles. The central station receives information by radio wave signals on the present location and present status of each vehicle on patrol at a sequence of times. Optionally, the vehicles may be divided into mutually exclusive groups, with each group reporting its location and status at separate times with different frequencies of reporting. An information response interval for a group includes a number of time slots, with each time slot allocated to a vehicle in the group so that no slot is empty. When the central station receives a call for assistance, an assistance message is transmitted to the fleet, specifying the site at which assistance is needed and any available information on the nature of the assistance required.