The present invention discloses a high-precision point positioning method and device based on a smartphone. The method of the present invention, which belongs to the technical field of satellite positioning, improves the conventional PPP uncombined positioning model, and only uses original GNSS observation values received by a smartphone to carry out high-precision positioning without GNSS reference stations. The positioning method of the present invention comprises following steps: acquiring original observation values of the smartphone, such as GNSS pseudoranges and carrier phases; after preprocessing the data to decrease part of error influences, generating an uncombined model from the original observation values according to an improved precise point positioning method based on an estimation of double clock biases; determining each satellite observation value weight according to a satellite elevation angle; and carrying out filtering positioning by an improved Kalman filtering method to give a high-precision point positioning result.

An apparatus for surveying a position of a static point, consisting of a GNSS receiver and a mobile computing device, connected with GNSS receiver via communication interface. The mobile computing device accepts from GNSS receiver several estimations of position of a static point within a single session and computes combined result for the current session, which is the average of those estimations. After that, a reset command is send to a GNSS receiver, and another session is performed in order to get another combined result. The process continues until a required number of mutually consistent session results is collected, where ‘consistent’ means having the scatter of session results within a certain margin. Upon collecting the required number of consistent session results, they are combined to compute a single estimate of the position of a static point, which is considered as a result of survey.

An apparatus for surveying a position of a static point, consisting of a GNSS receiver and a mobile computing device, connected with GNSS receiver via communication interface. The mobile computing device accepts from GNSS receiver several estimations of position of a static point within a single session and computes combined result for the current session, which is the average of those estimations. After that, a reset command is send to a GNSS receiver, and another session is performed in order to get another combined result. The process continues until a required number of mutually consistent session results is collected, where ‘consistent’ means having the scatter of session results within a certain margin. Upon collecting the required number of consistent session results, they are combined to compute a single estimate of the position of a static point, which is considered as a result of survey.

A method or system can include or be configured to receive a set of satellite observations, receiving sensor data, determining a position estimate and associated positioning error for a rover based on the set of satellite observations and the sensor data, determine a protection level associated with the position estimate based on a set of potential faults, and optionally provide an alert when the positioning error exceeds the protection level.

A signal processing apparatus and method provides the ability to dynamically select a subset of subcarriers from a received frequency division multiplex (FDM), select which subsets of subcarriers are coherently combined per satellite, and translate the selected subcarriers into a FDM having a smaller bandwidth. There are at least two first phase aligners, a digital cross-connect, and at least two second phase aligners. The first and second phase aligners are configured to receive a pair of in-phase and quadrature pairs and provide automatic gain control and coherent combing of the pairs. The digital cross-connect is configured to receive the in-phase and quadrature pairs from the two phase aligners and associate any in-phase and quadrature pair with another. Preferably, the apparatus further includes dual front-end digital channelizers configured to convert signals into an in-phase and quadrature pairs which are input to the first phase aligners.

A signal processing apparatus and method provides the ability to dynamically select a subset of subcarriers from a received frequency division multiplex (FDM), select which subsets of subcarriers are coherently combined per satellite, and translate the selected subcarriers into a FDM having a smaller bandwidth. There are at least two first phase aligners, a digital cross-connect, and at least two second phase aligners. The first and second phase aligners are configured to receive a pair of in-phase and quadrature pairs and provide automatic gain control and coherent combing of the pairs. The digital cross-connect is configured to receive the in-phase and quadrature pairs from the two phase aligners and associate any in-phase and quadrature pair with another. Preferably, the apparatus further includes dual front-end digital channelizers configured to convert signals into an in-phase and quadrature pairs which are input to the first phase aligners.

A method and apparatus are provided for calculating a position based on Global Navigation Satellite Systems (GNSS) signals. The method includes estimating a first state vector comprising a first set of float carrier range ambiguities using a first estimator, basedon first observations of the GNSS signals; and estimating a second state vector comprising a second set of float carrier range ambiguities using a second estimator, based on second observations of the GNSS signals. It further comprises fixing one or more first carrier range ambiguities, using a first strategy, based on the first set of float carrier range ambiguities; and fixing one or more second carrier range ambiguities, using a second strategy, based on the second set of float carrier range ambiguities. The first strategy for fixing the one or more first carrier range ambiguities is different from the second strategy for fixing the one or more second carrier range ambiguities. The method further includes: selecting a set of fixed carrier range ambiguities from among a plurality of different sets of fixed carrier range ambiguities, the plurality including at least the one or more fixed first carrier range ambiguities and the one or more fixed second carrier range ambiguities; and estimating the position based on the selected set of fixed carrier range ambiguities.

A method and apparatus are provided for calculating a position based on Global Navigation Satellite Systems (GNSS) signals. The method includes estimating a first state vector comprising a first set of float carrier range ambiguities using a first estimator, basedon first observations of the GNSS signals; and estimating a second state vector comprising a second set of float carrier range ambiguities using a second estimator, based on second observations of the GNSS signals. It further comprises fixing one or more first carrier range ambiguities, using a first strategy, based on the first set of float carrier range ambiguities; and fixing one or more second carrier range ambiguities, using a second strategy, based on the second set of float carrier range ambiguities. The first strategy for fixing the one or more first carrier range ambiguities is different from the second strategy for fixing the one or more second carrier range ambiguities. The method further includes: selecting a set of fixed carrier range ambiguities from among a plurality of different sets of fixed carrier range ambiguities, the plurality including at least the one or more fixed first carrier range ambiguities and the one or more fixed second carrier range ambiguities; and estimating the position based on the selected set of fixed carrier range ambiguities.

Secure range estimates as described herein may include determining a range estimate between two Bluetooth enabled devices based, at least in part, on round trip phase measurements of wireless signals transmitted between the devices. In one example, a range estimate may include determining a first set of relative carrier measurements at a first set of frequencies, determining a second set of relative carrier measurements based on the first set at the second set of frequencies; and combining the first set and the second set to estimate a distance between the devices.

Secure range estimates as described herein may include determining a range estimate between two Bluetooth enabled devices based, at least in part, on round trip phase measurements of wireless signals transmitted between the devices. In one example, a range estimate may include determining a first set of relative carrier measurements at a first set of frequencies, determining a second set of relative carrier measurements based on the first set at the second set of frequencies; and combining the first set and the second set to estimate a distance between the devices.