A position measuring system includes: a connection destination candidate selecting unit which selects a connection destination candidate for each of a plurality of route coordinates on a route included in route information, on the basis of the distance between each of the plurality of route coordinates and reference stations included in a reference station list; and a connection destination information generating unit which determines a connection destination for which to acquire the correction information, on the basis of prescribed determining criteria, from among the connection destination candidates selected by the connection destination candidate selecting means, and generates and outputs connection destination information relating to the determined connection destination.

A first bias conversion unit converts, based on a first frequency and a second frequency, a signal bias related to carrier phase for correcting a carrier phase contained in a first ranging signal having the first frequency, to a signal bias related to carrier phase for correcting a carrier phase contained in a second ranging signal having the second frequency. A first correction unit corrects the carrier phase using the converted signal bias. A second bias conversion unit converts the signal bias related to pseudorange to the signal bias related to pseudorange by making reference to a conversion table indicating values for use in conversion of the signal bias related to pseudorange to the signal bias related to pseudorange. A second correction unit corrects a pseudorange using the converted signal bias.

A low-earth orbit (LEO) satellite includes a global positioning receiver configured to receive first signaling from a first plurality of non-LEO navigation satellites. An inter-satellite transceiver is configured to send and receive inter-satellite communications with other LEO navigation satellites. At least one processor is configured to execute operational instructions that cause the at least one processor to perform operations that include: determining an orbital position of the LEO satellite based on the first signaling; and generating a navigation message based on the orbital position. A navigation signal transmitter configured to broadcast the navigation message to at least one client device, the navigation message facilitating the at least one client device to determine an enhanced position of the at least one client device based on the navigation message and further based on second signaling received from a second plurality of non-LEO navigation satellites.

A method, apparatus and computer program product are provided to correct a predicted value of the position of a navigation satellite and/or a clock offset of a clock of the navigation satellite. In the context of a method implemented by a client computing device, a prediction is received, from a serving computing device, that includes at least one predicted value for the position of the navigation satellite at one or more points in time within a prediction interval. The method also determines, with the client computing device, such as an Internet of Things device, at least one error component and, based thereupon, corrects the prediction received from the serving computing device by correction at least one predicted value for one or more of: (i) the position of the navigation satellite or (ii) the clock offset for the clock of the navigation satellite.

A method, apparatus and computer program product are provided to correct a predicted value of the position of a navigation satellite and/or a clock offset of a clock of the navigation satellite. In the context of a method implemented by a client computing device, a prediction is received, from a serving computing device, that includes at least one predicted value for the position of the navigation satellite at one or more points in time within a prediction interval. The method also determines, with the client computing device, such as an Internet of Things device, at least one error component and, based thereupon, corrects the prediction received from the serving computing device by correction at least one predicted value for one or more of: (i) the position of the navigation satellite or (ii) the clock offset for the clock of the navigation satellite.

A position fix identifying a geographic location of a receiver is received. The position fix was generated using signals received at the receiver from respective high-altitude signal sources (such as satellites). Imagery of a geographic area that includes the geographic location is also received. The imagery is automatically processed to determine whether one or more of the high-altitude signal sources were occluded from the geographic location when the position fix was generated. In response to determining that one or more of the high-altitude signal sources were occluded from the geographic location when the position fix was generated, the position fix is identified as being potentially erroneous.

A method for searching for a target object, which is moved along a path, by a measuring device which has a first reference system, a control device, and an operating controller which has a GNSS receiver having a second reference system and which is connectable to the measuring device via a communication connection.

A method for searching for a target object, which is moved along a path, by a measuring device which has a first reference system, a control device, and an operating controller which has a GNSS receiver having a second reference system and which is connectable to the measuring device via a communication connection.

A Real-Time Kinematic (RTK) solution is provided to mobile devices having multi-constellation, multi-frequency (MCMF) functionality, in which a single base station may have a baseline much farther than traditional base station and where the high accuracy positioning is achieved in a relatively short period of time. To enable this, embodiments involve modeling of an ionosphere-free carrier phase corresponding to combinations of at least three signals received from one or more satellites. The modeling retains the integer nature of carrier phase ambiguities, thereby allowing for fast convergence in determining the integer ambiguity of the carrier phases.

A low-earth orbit (LEO) satellite includes a global positioning receiver configured to receive first signaling from a first plurality of non-LEO navigation satellites of a constellation of non-LEO navigation satellites in non-LEO around the earth. An inter-satellite transceiver is configured to send and receive inter-satellite communications with other LEO navigation satellites in a constellation of LEO navigation satellites. At least one processor is configured to execute operational instructions that cause the at least one processor to perform operations that include: determining an orbital position of the LEO satellite based on applying precise point positioning (PPP) correction data to the first signaling, wherein the PPP correction data is received separately from the first signaling; and generating a navigation message based on the orbital position. A navigation signal transmitter is configured to broadcast the navigation message to at least one client device, the navigation message facilitating the at least one client device to determine an enhanced position of the at least one client device based on the navigation message.