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.

The present teaching relates to apparatus, method, medium, and implementations for initiating sensor calibration. A first GPS signal is received by a GPS receiver residing in an ego vehicle and is used to determine a first geo-position of the ego vehicle. A GPS related signal transmitted by a fiducial marker is received and is used to obtain a second geo-position of the fiducial marker. A distance between the ego vehicle and the fiducial marker is determined based on the first and second geo-positions and is used to determine whether to initiate calibration of one or more sensors using the fiducial marker.

A method, apparatus, and system are disclosed for providing modified orbital assistance data to a mobile station to determine its location using global navigation satellite system (GNSS). The modified orbital assistance data may include predicted orbital information for the GNSS satellites combined with antenna phase center offset data for one or more GNSS satellites. The antenna phase center offset data may indicate an offset distance from the center of mass of the GNSS satellite to a position on an antenna of the respective GNSS satellite. The modified orbital assistance data may be in an earth-centered earth-fixed (ECEF) frame of reference and the antenna phase center offset data may be in a body-centered frame of reference.

One or more processors obtain an indication of user input identifying a position of a mobile device within a vehicle. The processor(s) obtain a location of the mobile device with respect to a coordinate system that is independent of the vehicle. The processor(s) determine a location of the vehicle with respect to the coordinate system based at least in part on the location of the mobile device and the identified position of the mobile device within the vehicle. The location of the vehicle with respect to the coordinate system may be determined to sub-meter accuracy.

One or more processors obtain an indication of user input identifying a position of a mobile device within a vehicle. The processor(s) obtain a location of the mobile device with respect to a coordinate system that is independent of the vehicle. The processor(s) determine a location of the vehicle with respect to the coordinate system based at least in part on the location of the mobile device and the identified position of the mobile device within the vehicle. The location of the vehicle with respect to the coordinate system may be determined to sub-meter accuracy.

A device and method of use for the calibration of a detector. The calibration device includes a first source configured to produce first electromagnetic energy EMR. A first diffuser is connected to the first source and is configured to accept the first EMR and provide a first diffused portion of the first EMR. An integrating sphere defines an interior and is optically connected to the first diffuser, and is configured to accept the first diffused portion from the first diffuser into the interior. An exit port connected to the integrating sphere is configured to pass at least a portion of electromagnetic energy. A thermal mechanism is configured to adjust and maintain the temperature of at least the first source. The integrating sphere is configured to pass only a second portion of the first diffused portion of the first EMR from the first diffuser to the exit port. In another embodiment, the calibration device has an arm, an actuator, and a module. The module supports at least a first source that emits electromagnetic energy, a thermal mechanism, and a controller. The actuator is configured to move the arm and module to a calibration position enabling the first source to be within the line of sight of an external detector, while the controller is configured to control the thermal mechanism enabling precise temperature regulation of the source and therefore the regulation of the emitted electromagnetic energy. When the device is not in the calibration position, the actuator is configured to move the arm and module to a stowed position, protecting the device from ambient electromagnetic radiation and harm.

A method, apparatus, and system are disclosed for providing modified orbital assistance data to a mobile station to determine its location using global navigation satellite system (GNSS). In some example embodiments, a method for determining a location of a mobile station using orbital assistance data may include: receiving satellite positioning signals from a plurality of GNSS satellites; receiving orbital assistance data comprising a distance between a location on an antenna which is associated with a first frequency of the satellite positioning signals and a location on the antenna which is associated with a second frequency of the satellite positioning signals; and determining the location of the mobile station based on the orbital assistance data and the satellite positioning signals.

A method and corresponding device for detecting correction information for an antenna for receiving data of a satellite of a satellite navigation system includes the steps of determining first distance information of the antenna relative to a satellite of a satellite navigation system, capturing position information and orientation information of the antenna on the basis of sensor information, determining second distance information of the antenna relative to the satellite on the basis of the position information captured using sensor information, detecting a deviation of the first distance information from the second distance information, determining correction information on the basis of the detected deviation, and storing, in a data memory, the correction information regarding the orientation information captured by the sensor information. The correction information can be used in particular for correcting an angle-dependent phase center offset.

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.

System and method for adjusting timing error in a mobile device. In the mobile device, a crystal oscillator (XO) is used by a system timer as the timing source. When the mobile device enters into a sleep mode, the system timer is set to time the duration of the sleep mode. During the sleep mode, a thermistor is used to measure and monitor the temperature changes of the XO. After the sleep mode is over, a processor in the mobile device determines the frequency changes of the XO based on the temperature changes of the XO. Based on the frequency changes of the XO, the processor determines the timing error that may have occurred when the system timer was timing the sleep mode and determines the actual duration of the sleep mode by adjusting the duration timed by the system timer based on the timing error.