Abstract:
A computer-implemented method for generating at least one segment of an offset path for a vehicle based on at least one segment of a base path is provided. The at least one segment of the base path is represented by a stored set of data points. The computer-implemented method includes comparing the at least one segment of the base path to a curvature constraint to determine if the at least one segment of the base path violates the curvature constraint. The curvature constraint is based on a characteristic of the vehicle and a desired offset distance from the at least one segment of the base path. The characteristic reflects the vehicle's ability to traverse at least one segment of a path. The method further includes modifying the at least one segment of the base path to satisfy the curvature constraint, if the at least one segment of the base path violates the curvature constraint. At least one segment of an offset path for the vehicle to follow is generated based upon the desired offset distance from the modified at least one segment of the base path.
Abstract:
A rover processor determines position of a rover based upon the interaction between multiple antennas located at the rover and multiple antennas located at a base. The rover antennas may include a rover master antenna having a phase center located at the centroid of the antennas patterns of at least two auxiliary rover antennas. The rover processor may determine the position of the rover master antenna based upon the relative positions of at least two rover antennas (e.g., the rover master antenna and at least one rover auxiliary antenna, or at least two rover auxiliary antennas) with respect to at least two antennas of a base transceiver.
Abstract:
The position of a global navigation satellite system (GNSS) surveying receiver is determined based on a plurality of RTK engines. A first RTK engine is implementing using a first set of parameters. A second RTK engine is implemented using a second set of parameter different than the first set. A plurality of GNSS signals are received from multiple satellites. At least one correction signal is received from at least one base receiver. A first position is determined from the first RTK engine based on the GNSS signals and the at least one correction signal. A second position is determined from the first RTK engine based on the GNSS signals and the at least one correction signal. A final position of the GNSS surveying receiver is determined based on the first position or the second position or a combination of both positions.
Abstract:
A rover processor determines position of a rover based upon the interaction between multiple antennas located at the rover and multiple antennas located at a base. The rover antennas may include a rover master antenna having a phase center located at the centroid of the antennas patterns of at least two auxiliary rover antennas. The rover processor may determine the position of the rover master antenna based upon the relative positions of at least two rover antennas (e.g., the rover master antenna and at least one rover auxiliary antenna, or at least two rover auxiliary antennas) with respect to at least two antennas of a base transceiver.
Abstract:
The measurements of two GPS and/or GLONASS receivers are related to a common time moment by extrapolating measurement data that has arrived through a connection link with a delay. This common time moment is defined by the user. Cycle slips in the phase-lock loops (PLLs) of the receivers, which may be caused by blockage of direct signals from the satellites, strong interference signals, and reflections, are deflected and corrected in a multi-loop nonlinear tracking system. The procedure of resolution of phase measurement ambiguities comprises the preliminary estimation of floating ambiguities by a recurrent (e.g., iterative) procedure including the simultaneous processing of code and phase measurements for all satellites for each processing time interval, and the gradual improvement of the result as the information is accumulated. After the resolution of ambiguity, the user coordinates are estimated with centimeter accuracy on the basis of phase measurements on the carrier frequency.
Abstract:
A portable geodetic surveying station is disclosed which utilizes a GPS antenna attached to the top portion of a surveyor's stake, or other type monopod. By positioning the bottom portion of the monopod directly upon a desired ground location, and adjusting the angular position of the monopod so that it is precisely vertical, the GPS antenna may be quickly and accurately positioned level and directly above the desired ground location. Additionally, because the monopod has a known, fixed length, the height of the GPS antenna above the desired ground location will always be a constant, and will not vary from one survey point to the next. The GPS antenna and monopod are designed to be used in conjunction with a newly designed geodetic surveying tripod which can be quickly and conveniently set up to support the monopod in its vertical position directly above the desired ground location. The tripod of the present invention includes a tripod head which comprises a base platform, a first housing slidably mounted on the platform to permit the first housing to move along a first directional path, and a second housing slidably mounted within the first housing to permit the second housing to move along a second directional path, generally orthogonal to the first directional path. Mounted pivotally within the second housing is a gimbal which includes a central cavity for receiving the shaft of the monopod. The gimbal allows the angular position of the monopod and GPS antenna to be adjusted independently of the angular position tripod platform.
Abstract:
An apparatus for determining signal strength data within allocated GNSS frequency band(s) is provided. The apparatus includes a GNSS antenna. The GNSS antenna receives signals within the allocated GNSS frequency band. The apparatus further includes receiving circuitry. The receiving circuitry is for demodulating the received signals. The apparatus further includes a processor and memory for storing instructions, executable by the processor. The instructions include instructions for generating signal strength data for the received signals within the GNSS allocated frequency based on the demodulated signals, and for determining a position for a point of interest based upon the demodulated signals. Included in the apparatus is a display screen for displaying a graphical representation of the signal strength data of at least a portion of the at least one GNSS allocated frequency band. The graphical representation identifies interference within at least the portion of the at least one GNSS allocated frequency band.
Abstract:
A handheld GNSS device includes a housing, handgrips integral to the housing for enabling a user to hold the device, and a display screen integral with the housing. The device has a GNSS antenna and a communication antenna, both integral with the housing. The GNSS antenna receives position data from GNSS satellites. The communication antenna receives positioning assistance data from a base station. The GNSS antenna has a first antenna pattern, and the communication antenna has a second antenna pattern. The first and second antenna patterns are substantially separated. Coupled to the GNSS antenna, within the housing, is at least one receiver. Further, the device includes, within the housing, orientation circuitry for generating orientation data, imaging circuitry for obtaining image data, and positioning circuitry for determining a position for the point of interest based on the position data, the positioning assistance data, the orientation data, and the image data.
Abstract:
A rover processor determines position of a rover based upon the interaction between multiple antennas located at the rover and multiple antennas located at a base. The rover antennas may include a rover master antenna having a phase center located at the centroid of the antennas patterns of at least two auxiliary rover antennas. The rover processor may determine the position of the rover master antenna based upon the relative positions of at least two rover antennas (e.g., the rover master antenna and at least one rover auxiliary antenna, or at least two rover auxiliary antennas) with respect to at least two antennas of a base transceiver.
Abstract:
A handheld GNSS device for determining position data for a point of interest is provided. The device includes a housing, handgrips integral to the housing for enabling a user to hold the device, and a display screen integral with the housing for displaying image data and orientation data to assist a user in positioning the device. The device further includes a GNSS antenna and at least one communication antenna, both integral with the housing. The GNSS antenna receives position data from a plurality of satellites. One or more communication antennas receive positioning assistance data related to the position data from a base station. The GNSS antenna has a first antenna pattern, and the at least one communication antenna has a second antenna pattern. The GNSS antenna and the communication antenna(s) are configured such that the first and second antenna patterns are substantially separated. Coupled to the GNSS antenna, within the housing, is at least one receiver. Further, the device includes, within the housing, orientation circuitry for generating orientation data of the housing based upon a position of the housing related to the horizon, imaging circuitry for obtaining image data concerning the point of interest for display on the display screen, and positioning circuitry, coupled to the at least one receiver, the imaging circuitry, and the orientation circuitry, for determining a position for the point of interest based on at least the position data, the positioning assistance data, the orientation data, and the image data.