Positioning augmentation device, positioning augmentation method, and computer readable medium

A positioning augmentation device to augment positioning with use of a plurality of positioning satellites and in a region including a plurality of electronic reference points and a plurality of evaluation points whose position coordinates are respectively specified, the positioning augmentation device comprising:

• processing circuitry
• to generate an amount of correction for a phase pseudorange between the positioning satellite and each of the plurality of evaluation points, as an amount of evaluation point correction for each of the plurality of evaluation points, based on a carrier phase of a positioning signal sent out from the positioning satellite and observed at each of the plurality of electronic reference points,
• to acquire a geometric distance between the positioning satellite and each of the plurality of evaluation points, based on the positioning signal sent out from the positioning satellite and observed at each of the plurality of evaluation points, and to calculate a difference between the phase pseudorange and the geometric distance as an amount of reference correction for each of the plurality of evaluation points,
• to remove a bias component due to ambiguity from a difference between the amount of evaluation point correction and the amount of reference correction and to calculate the difference from which the bias component due to the ambiguity has been removed, as a ranging error at each of the plurality of evaluation points, and
• to generate an alert indicating impossibility of the positioning with use of the plurality of positioning satellites, in accordance with a number of satellites or a number of types of the satellites, among the plurality of positioning satellites, that are determined as anomalous based on the ranging error.

A positioning augmentation method for a positioning augmentation device to augment positioning with use of a plurality of positioning satellites and in a region including a plurality of electronic reference points and plurality of evaluation points whose position coordinates are respectively specified, the positioning augmentation method comprising:

• generating an amount of correction for a phase pseudorange between the positioning satellite and each of the plurality of evaluation points, as an amount of evaluation point correction for each of the plurality of evaluation points, based on a carrier phase of a positioning signal sent out from the positioning satellite and observed at each of the plurality of electronic reference points,
• acquiring a geometric distance between the positioning satellite and each of the plurality of evaluation points, based on the positioning signal sent out from the positioning satellite and observed at each of the plurality of evaluation points, and calculating a difference between the phase pseudorange and the geometric distance as an amount of reference correction for each of the plurality of evaluation points,
• removing a bias component due to ambiguity from a difference between the amount of evaluation point correction and the amount of reference correction and calculating the difference from which the bias component due to the ambiguity has been removed, as a ranging error at each of the plurality of evaluation points;
• and
• generating an alert indicating impossibility of the positioning with use of the plurality of positioning satellites, in accordance with a number of satellites or a number of types of the satellites, among the plurality of positioning satellites, that are determined as anomalous based on the ranging error.

A non-transitory computer readable medium storing a positioning augmentation program for a positioning augmentation device to augment positioning with use of a plurality of positioning satellites and in a region including a plurality of electronic reference points and a plurality of evaluation points whose position coordinates are respectively specified, the positioning augmentation program that causes the positioning augmentation device being a computer to execute:

• a correction generation process of generating an amount of correction for a phase pseudorange between the positioning satellite and each of the plurality of evaluation points, as an amount of evaluation point correction for each of the plurality of evaluation points, based on a carrier phase of a positioning signal sent out from the positioning satellite and observed at each of the plurality of electronic reference points,
• a reference calculation process of acquiring a geometric distance between the positioning satellite and each of the plurality of evaluation points, based on the positioning signal sent out from the positioning satellite and observed at each of the plurality of evaluation points, and calculating a difference between the phase pseudorange and the geometric distance as an amount of reference correction for each of the plurality of evaluation points,
• a ranging error calculation process of removing a bias component due to ambiguity from a difference between the amount of evaluation point correction and the amount of reference correction and calculating the difference from which the bias component due to the ambiguity has been removed, as a ranging error at each of the plurality of evaluation points, and
• an alert generation process of generating an alert indicating impossibility of the positioning with use of the plurality of positioning satellites, in accordance with a number of satellites or a number of types of the satellites, among the plurality of positioning satellites, that are determined as anomalous based on the ranging error.