Methods and apparatus for tracking a plurality of satellite signals received by a Global Navigation Satellite System, GNSS, receiver from a plurality of satellites, each satellite signal being processed in a different one of a plurality of channels (100a-k; 300a-k) of the GNSS receiver. At least one summing unit (116, 120; 356, 358, 360; 366) is configured to sum corresponding correlation values from each of a plurality of sets of correlation values, each set from one of the plurality of channels, to determine a plurality of summed correlation values, wherein each correlation value in a set represents a correlation between a signal derived from a corresponding one of the plurality of received satellite signals, and one of a plurality of replica signals each based on a known position and/or velocity of the GNSS receiver and one of a plurality of estimated receiver timing parameters. A hypothesis evaluation unit (118, 122; 318, 322) is configured to determine a maximum correlation value based on the plurality of summed correlation values, and to determine a most likely one of a plurality of receiver timing hypotheses to be the receiver timing hypothesis corresponding to the maximum correlation value.

An entity, such as a mobile device or base station, measures downlink position referencing signals (PRS) occasions or uplink position sounding referencing signal occasions for supporting estimating the position of the mobile device. The entity, for example, performs a plurality of positioning measurements from a plurality of consecutive PRS occasions received in a bundle from one or more base stations or from a mobile device. Each PRS occasion may include one or more slots and may be narrowband or non-narrowband. The bundled, e.g., consecutive, PRS occasions may be transmitted with a periodicity that is sufficient to maintain a desired throughput. Moreover, with the use of bundled PRS occasions, power consumption of the mobile device, as well as effects of clock drift and mobile device movement, may be minimized.

Methods and apparatus for sensor calibration of a system having an aperture, primary mirror, secondary mirror, and a sensor, such as an FPA IR sensor. A calibration system includes calibration energy sources with a movable first mirror configured to be selectively inserted into the optical path and select one of the calibration energy sources and a second mirror configured to image the selected calibration energy source.

A system for managing a time reference includes a real-time clock, an interface, and a processor. The real-time clock store an RTC time. The interface is configured to receive a GPS time and a cellular time. The processor is configured to: indicate to start a time-speed adjustment loop; determine a true time based at least in part on the GPS time and the cellular time; determine an error between the true time and the RTC time; determine an RTC speed calibration adjustment based at least in part on the error; and adjust the real-time clock speed based at least in part on the RTC speed calibration adjustment.

According to an embodiment, an apparatus for precise position correction using a positioning difference comprises a first distribution information obtaining unit gathering first distribution information from an external terminal, a global navigation satellite system (GNSS) receiver obtaining a GNSS positioning value of the apparatus based on a GNSS, and a positioning correcting unit obtain a corrected location of the apparatus by correcting the GNSS positioning value using the gathered first distribution information. The first distribution information includes a GNSS positioning value of the external terminal, a GNSS positioning time, a precise positioning value, and a positioning difference between the GNSS positioning value and the precise positioning value.

A positioning calibration controller for measuring and calibrating the configuration dimensions of a construction working machine having an machine body including a first surveying device for surveying the position coordinates and a movable working tool including one or more angle detecting devices, wherein the positioning calibration method and the positioning calibration controller of the construction working machine having the feature of specifying the configuration dimensions and the configuration positions of the movable business tool by the position measurement data and the angle data detected by the angle detecting device by measuring the position coordinates of the plurality of posture positions of the movable business tool by a second surveying device.

An apparatus for forming wideband pseudo random noise signals includes a set of channels each comprising an NCO having a controlled frequency and phase and a PRN code generator, the NCO generating a strobe that is output to the PRN code generator. The PRN code generator forms a new sequence element of +1 or −1 in response to the strobe. The apparatus also comprises a first modulator having a plurality of weight coefficients, a plurality of multipliers each multiplying one of the weight coefficients, an adder outputting a sum of the plurality of multipliers output signals, and a mixer with a quadrature output signal multiplying the adder's output by sine and cosine of a low intermediate frequency. The apparatus also includes a processor controlling the set of channels, a transceiver module to receive and/or transmit quadrature signals, and an interface connecting the output of the mixer and the transceiver module.

A method includes outputting a plurality of simulated global navigation satellite system (GNSS) and interference signal pairs comprising a simulated GNSS signal and a simulated interference signal. Each of the simulated GNSS signals, or the simulated interference signals, has an associated reference signal. A calibration GNSS signal that combines the simulated GNSS signals and the associated reference signals, or a calibration interference signal that combines the simulated interference signals and the associated reference signals is received. A phase, time, or a power offset is calculated for the simulated GNSS signals based on the calibration GNSS signal and the associated reference signals, or for the simulated interference signals based on the calibration interference signal and the associated reference signals. A corrected plurality of simulated GNSS and interference signal pairs are output based on the calculated phase, time, or power offset for the simulated GNSS signals or for the simulated interference signals.

A method of calibrating a total station using a GNSS device includes physically coupling the total station with the GNSS device at a first location; determining the position of the total station at the first location based on position data received by the GNSS device; decoupling the total station from the GNSS device; moving the GNSS device to a second location while leaving the total station at the first location; determining the position of the GNSS device at the second location based on position data received by the GNSS device; adjusting the position of a camera on the total station to image the GNSS device while at the second location; determining axes of the camera based on the orientation of the camera and the determined positions at the first and second locations; and calibrating encoders of the total station based on the determined axes.

An apparatus and method of intersensor calibration including using a zero airmass response constant proportional to sensor absolute radiometric gain coefficients to monitor sensor radiometric stability. Tracking the ratio of zero airmass response constant values for similar bands between two sensors provides a parameter on a common radiometric scale for evaluating interoperability performance. The method includes imaging a solar signal using a mirror to create an image reference target, detecting the image reference target using a first sensor, generating a zero airmass response constant based on a ground sampling distance of the first sensor and an at-sensor radiance value, computing a radiometric gain coefficient of the first sensor using the zero airmass response constant, and comparing the radiometric gain coefficient of the first sensor to a radiometric gain coefficient of a second sensor to determine a gain ratio between the first sensor and second sensor.