Abstract: A first position determining device at a known position transmits a data signal identifying the known position. A second position determining device is responsive to the data signal and movable to a position near but displaced from a survey point. The position of the second position determining device is determined relative to the known position, and the range and bearing of the survey point is determined relative to the second position determining device.

Abstract: A lane change alarm using data for a highway track. A highway track database provides geographical location points for a track of a highway lane. A differential global positioning system (DGPS) receiver provides a vehicle location. A longitudinal track matching code matches the vehicle location against a track location and provides a longitudinal direction and a transverse distance to an alarm gate. The alarm gate indicates an alarm condition unless a lane change signaler is operated for indicating that the lane change is intentional. The highway track database is created using a similar DGPS receiver by determining and recording highway track location points for a selected highway lane while driving on the highway lane.

Abstract: An electronic distance meter comprises an integrated circuit from a GPS navigation receiver having a local pseudo-random number code generator for code demodulation that is connected to modulate either a polychromatic or a monochromatic light source. An optical system focuses the light on a distant target with an unknown range. Reflections from the distant target are focused on a light detector that produces a phase-delayed copy of the original pseudo-random number code. The time-of-flight to and back from the distant target is a function of the distance. The GPS receiver integrated circuit computes the range based on the code-phase delay to a precision better than one centimeter. The position of a remote target can be triangulated from several electronic distance meters each having known positions, e.g., determined by included GPS navigation receivers.

Abstract: A method for accurately determining the location of a pre-selected survey or construction mark, or for accurately identifying the survey position for a new mark with pre-selected location coordinates. A Satellite Positioning System (SPS), such as GPS or GLONASS, with at least two SPS stations (antennas and receiver/processors) is used to receive and analyze SPS signals from four or more SPS signal satellites. An SPS signal reference station is placed at a position with known location coordinates, which can be stationary or be known functions of time. An SPS signal roving station receives the location coordinates of the reference station and determines its own location coordinates relative to the reference station, using SPS differential positioning. The roving station is then moved to a pre-selected survey mark or position, either to locate that survey mark or to identify (by marking) a new survey position from pre-selected location coordinates.

Abstract: Apparatus that is carried on a land vehicle, a marine vehicle or vessel, or an airborne vehicle or vessel for notifying others that a vehicle accident or other abnormal situation has occurred and for notifying others of the location of the vehicle at the time of the accident. The vehicle carries an distance measuring system (DMS) signal antenna and receiver/processor that receives DMS-type signals from one or more DMS signal broadcasters and determines the present position of the vehicle, plus an activatable transmitter. The vehicle also carries an abnormality sensing means that senses the occurrence of an accident or other abnormal situation involving the vehicle or a vehicle occupant. When an abnormal situation is sensed, the abnormality sensing means automatically activates the transmitter, which then communicates the fact that an abnormal situation has occurred and the location of the vehicle at the time the event occurred.

Abstract: An averaging frequency counter for determining the frequency of recurrence of input signals has an event counter for counting a number of the input signals, a gate counter for counting a number of time intervals during which the input signals are counted, and a time interval measurement circuit for measuring the cumulative duration of the time intervals. A systematic error associated with the measurement of the duration of each time interval is determined during an application of a calibrated frequency to the averaging frequency counter by dividing a calculated total time error by the number of time intervals. The systematic error is subsequently used to correct a measurement of an unknown frequency during an application of the unknown frequency to the averaging frequency counter by subtracting a product of the number of the time intervals and the systematic error from the cumulative duration.

Abstract: Apparatus that is carried on a land vehicle, a marine vehicle or vessel, or an airborne vehicle or vessel for notifying others that a vehicle accident or other abnormal situation has occurred and for notifying others of the location of the vehicle at the time of the accident. The vehicle carries an distance measuring system (DMS) signal antenna and receiver/processor that receives DMS-type signals from one or more DMS signal broadcasters and determines the present position of the vehicle, plus an activatable transmitter. The vehicle also carries an abnormality sensing means that senses the occurrence of an accident or other abnormal situation involving the vehicle or a vehicle occupant. When an abnormal situation is sensed, the abnormality sensing means automatically activates the transmitter, which then communicates the fact that an abnormal situation has occurred and the location of the vehicle at the time the event occurred.