A satellite signal receiving apparatus and an antenna pattern adjusting method thereof are provided. A coupling relationship between a main antenna and a plurality of pattern adjustment antennas is adjusted to thereby adjust an angle of the antenna pattern so that the average intensity of satellite signals attributed to target satellites and received by an antenna array is higher than a first preset intensity.

A modal antenna is implemented to provide a variable radiation pattern for improved global positioning system (GPS) signal reception. A multitude of antenna radiation patterns generated from a modal antenna provide the capability to optimally acquire GPS signals across a wide range of angles of arrival. Minimum radiation pattern roll-off is observed from the composite pattern generated from the multiple patterns. An algorithm is described that reduces the acquisition time for a location fix for cold and hot start conditions.

Provided is a method for matching telemetry packets for satellite image processing, which includes receiving a plurality of image data telemetry packets and a plurality of auxiliary data telemetry packets, the plurality of image data telemetry packets include satellite image data photographed from a satellite, but do not include satellite image sequence information, and the plurality of auxiliary data telemetry packets include satellite image sequence information, correcting a packet time of either the plurality of image data telemetry packets or the plurality of auxiliary data telemetry packets by using a predetermined mathematical formula, and matching the plurality of image data telemetry packets and the plurality of auxiliary data telemetry packets corresponding to the same satellite image sequence by using the packet time.

Provided is a method for matching telemetry packets for satellite image processing, which includes receiving a plurality of image data telemetry packets and a plurality of auxiliary data telemetry packets, the plurality of image data telemetry packets include satellite image data photographed from a satellite, but do not include satellite image sequence information, and the plurality of auxiliary data telemetry packets include satellite image sequence information, correcting a packet time of either the plurality of image data telemetry packets or the plurality of auxiliary data telemetry packets by using a predetermined mathematical formula, and matching the plurality of image data telemetry packets and the plurality of auxiliary data telemetry packets corresponding to the same satellite image sequence by using the packet time.

A positioning system operates by first determining that a user is pedestrian, and then estimating a speed of the user. Having tracked a first signal from one radio transmitter whose position is known, the system attempts to detect additional signals from the one transmitter, in a search space such that the first signal and the or each additional signal are consistent with the estimated speed of the user and with one or more of the signals having been reflected off a reflector in the vicinity of the user. One or more detected additional signals from the one transmitter are then tracked, and candidate measurements, derived from the first signal and the one or more detected additional signals, are provided for use when estimating the position and/or velocity of the user.

A positioning system operates by first determining that a user is pedestrian, and then estimating a speed of the user. Having tracked a first signal from one radio transmitter whose position is known, the system attempts to detect additional signals from the one transmitter, in a search space such that the first signal and the or each additional signal are consistent with the estimated speed of the user and with one or more of the signals having been reflected off a reflector in the vicinity of the user. One or more detected additional signals from the one transmitter are then tracked, and candidate measurements, derived from the first signal and the one or more detected additional signals, are provided for use when estimating the position and/or velocity of the user.

A method for calibrating a multichannel GNSS receiver which does not require the use of a specific signal generator and which may be implemented directly on the basis of simple measurements taken from a receiver in operation comprises determining a first, broadband equalization filter which may be positioned at the output of the RF reception channels and at the input of the correlators in order to correct the mismatch between the various RF reception channels. The invention also consists of determining a second, narrowband equalization filter in order to correct residual phase and gain errors.

A positioning satellite selection device that obtains a selection combination of positioning satellites used for positioning of a positioning target, and includes: a positioning data acquisition unit that acquires positioning data or navigation information, a range observation value, and an error correction value of this range observation value of a positioning satellite; a satellite position calculator that calculates a satellite position of the positioning satellite from the navigation information; a quality evaluation unit that evaluates quality of the positioning data; a shortest time designation unit that sets a shortest selection time during which the positioning satellite is selected to a larger value as poorer the quality; a plan creator that obtains the selection combination by selecting a positioning satellite conditioned on selecting for longer than the shortest selection time; and a plan storage that stores a plan of the selection combination of positioning satellites.

A positioning satellite selection device that obtains a selection combination of positioning satellites used for positioning of a positioning target, and includes: a positioning data acquisition unit that acquires positioning data or navigation information, a range observation value, and an error correction value of this range observation value of a positioning satellite; a satellite position calculator that calculates a satellite position of the positioning satellite from the navigation information; a quality evaluation unit that evaluates quality of the positioning data; a shortest time designation unit that sets a shortest selection time during which the positioning satellite is selected to a larger value as poorer the quality; a plan creator that obtains the selection combination by selecting a positioning satellite conditioned on selecting for longer than the shortest selection time; and a plan storage that stores a plan of the selection combination of positioning satellites.

A global navigation satellite system (GNSS) receiver includes a processor to determine whether a first satellite is in view of GNSS receiver; whether a second satellite is in view of GNSS receiver when first satellite is in view of GNSS receiver; and whether a third satellite is in view of GNSS receiver when first satellite is not in view of GNSS receiver. Second satellite was previously determined more likely to be in view when first satellite is in view based on a first average distance between first satellite and second satellite based on a first orbit of first satellite and a second orbit of second satellite. Third satellite was previously determined more likely to be in view when first satellite is not in view based on a second average distance between first satellite and third satellite based on first orbit of first satellite and a third orbit of third satellite.