Abstract:
Some embodiments of the invention provide a location-determination system that includes several transmitters and at least one receiver. Each transmitter transmits a signal that includes a unique periodically-repeating component, and the receiver receives a reference signal. Based on the received reference signal, the location-determination system identifies an estimated location of the receiver as follows. For each transmitter in a set of transmitters, the system computes a phase offset between the received reference signal and a replica of the transmitter's periodically-repeating component. The system also identifies an approximate location of the receiver and an approximate receive time for the received signal. The system then uses the identified approximate location and time, and the computed phase offsets, to compute pseudoranges for the set of transmitters. Finally, the system identifies the estimated location of the receiver by using the computed pseudoranges.
Abstract:
At least one preset radio terminals (101, 102) are registered in advance as a group in an administration station (108) connected to a switched network (104), a position information acquisition request for a desired group is made from a position information acquisition terminal such as a portable phone (103), the administration station (108) requests the transmission of current position information to all the radio terminals (101, 102) in a group responding to that request, each radio terminal (101, 102) receiving this request determines the current position of own terminal on receiving radio wave from GPS satellites (109, 110) for transmission to the administration station (108), the station (108) returns the received current position information to the portable phone (103) requesting a position information acquisition, and the portable phone (103) displays the current position of each radio terminal matching the current position information.
Abstract:
The invention concerns a system for tracking a moving object from a control station, using signals transmitted by satellites of a positioning system and relayed by a transponder mounted on the mobile and which performs, when passing, a frequency change on the signals coming from the positioning system satellites. The invention also concerns specific demodulation circuits in reception, in a control station, enabling to obtain coherent measurements of pseudo-distances and pseudo-speeds.
Abstract:
A mobile radiocommunications terminal contains or is operatively connected to a position estimator, such as a GPS receiver. The mobile terminal stores at least one reference position. The mobile terminal updates its position at a frequency that is a function of its distance from the reference position, or as a function of the rate of change of its distance from the reference position.
Abstract:
A personal golfing assistant system is comprised of software running on a PDA that is attached either directly or remotely to a GPS receiver that enables the user to engage in a process of easily surveying and/or electronically capturing geophysical data pertinent to the game of golf such as the location of the center of the green, zones on the green, bunkers, water, trees, hazards, etc. Software allows a golfer to use a handheld PDA/GPS unit in the course of play to mark a ball location automatically and/or determine the distance to various targets and avoidance objects and add additional objects. The system can send a set of parameters tailored for a specific course to a real-time tunable GPS to adjust for optimal performance and can adjust measurements to compensate for changes in environmental conditions. Software analyzes golf data and generates useful statistics.
Abstract:
A system for tracking objects outdoors. Tags (202) attached to objects such as trailers include GPS receivers (203). Tags transmit uncorrected position and satellite data to a base station (205), where differential corrections are applied, providing 2-5 meter accuracy of the position of the tag and object. Tags are on a low duty cycle. When a tag powers on, it receives accurate time and current satellite data from the base station, enabling the tags to acquire the satellite signal quickly and with minimum power consumption. When a tag is out of base station range, the tag periodically calculates and archives its position. The tag may also include Real Time Locating Systems technology, to enable tracking to continue when the tag moves indoors and becomes inacessible to GPS satellite signals.
Abstract:
The invention relates to a driver assistance system of a motor vehicle and to a method for operating a drive assistance system of a motor vehicle. The invention comprises a detection means (24, 28, 30) for predetermined, instantaneous environmental parameters of a momentary traffic situation, a comparing means (28; 34) for comparing the detected instantaneous environmental parameters with stored environmental parameters which are acceptable for the driver assistance system. The inventive system also comprises an activating/deactivating means (28) for deactivating the drive assistance system if predetermined, instantaneous environmental parameters are located outside the environmental parameters which are acceptable for the driver assistance system, or the driver assistance system is activated if predetermined, instantaneous environmental parameters are located within the environmental parameters which are acceptable for the driver assistance system.
Abstract:
An object in a storage area or moving vehicle is monitored by attaching an electronic tag (16) to the object (12). An electronic device (15) 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 method and apparatus for measuring time related to satellite data messages which are used with satellite positioning systems (SPS). In one method, a first record of at least a portion of a satellite data message is received at an entity, which is typically a basestation. The first record is compared with a second record of the satellite data message, where the first record and the second record overlap at least partially in time. Then a time is determined from this comparison, and this time indicates when the first record (or the source from which the first record was obtained) was received at a remote entity which is typically a mobile SPS receiver. Various other methods of the invention are described and various apparatuses of the invention are also described. The methods and apparatuses measure time of day using SPS signals without reading the satellite data messages which are transmitted as data within these signals. The methods and apparatuses are suitable for situations in which the received signal level is too weak to allow reading of the satellite data messages.
Abstract:
A system of GPS devices which receive civilian GPS signals and provide an intuitive graphical interface for displaying the relative position of GPS devices in relation to each other, the relative position being accurate to several meters and defined as the distance to, direction of and height variance between GPS devices. A first GPS device with the person or object to be located transmits its GPS determined location to a second GPS device. This second GPS device includes a means for receiving the GPS determined position of the first GPS device, and also includes means for calculating the relative position of the first GPS device relative to the second GPS device based on a comparison of the received telemetry of the first GPS device and its own GPS determined position. The relative position of the first device is then graphically displayed on an interface of the second GPS device in a manner which eliminates the need for a map in order to travel to the location of the first GPS device. While providing an interface which displays a relative position of the first GPS device, this information remains accurate no matter how the orientation of the second GPS device changes with respect to a compass.