US 2019/0094379 A1 · THREE-DIMENSIONAL CITY MODELS AND SHADOW MAPPING TO IMPROVE ALTITUDE FIXES IN URBAN ENVIRONMENTS

Abstract

The disclosed embodiments use 3D city models and shadow mapping to improve altitude fixes in urban environments. In an embodiment, a method comprises: generating a set of three-dimensional (3D) candidate positions in a geographic area of interest; predicting global navigation satellite system (GNSS) signal visibility at selected ones of the 3D candidate positions; receiving GNSS signals at a current location of the mobile device; determining observed satellite visibility based on the received GNSS signals; comparing the predicted satellite visibility with the observed satellite visibility; determining a position fix based on a result of the comparing; determining an indoor environment where the mobile device is located based at least on an altitude component of the position fix; obtaining structural data for the identified indoor environment; and determining a floor lower bound for the current location of the mobile device based on the altitude component and the structural data.

Claims20

Dependent claims

A method comprising:

generating, by a processor of a mobile device, a set of three-dimensional (3D) candidate positions in a geographic area of interest;
predicting, by the processor, global navigation satellite system (GNSS) signal visibility at selected ones of the 3D candidate positions;
receiving, by a GNSS receiver of the mobile device, GNSS signals at a current location of the mobile device;
determining, by the processor, observed satellite visibility based on the received GNSS signals;
comparing the predicted satellite visibility with the observed satellite visibility;
determining, by the processor, a position fix based on a result of the comparing;
determining, by the processor, an indoor environment where the mobile device is located based at least on an altitude component of the position fix;
obtaining, by the processor, structural data for the identified indoor environment;
and
determining, by the processor, a floor lower bound for the current location of the mobile device based on the altitude component and the structural data.

7 more elements

A system comprising:

one or more processors;
memory coupled to the one or more processors and configured to store instructions, which, when executed by the one or more processors, cause the one or more processors to perform operations comprising:
generating a set of three-dimensional (3D) candidate positions in a geographic area of interest;
predicting global navigation satellite system (GNSS) signal visibility at selected ones of the 3D candidate positions;
receiving GNSS signals at a current location of a mobile device;
determining observed satellite visibility based on the received GNSS signals;
comparing the predicted satellite visibility with the observed satellite visibility;
determining a position fix based on a result of the comparing;
determining an indoor environment where the mobile device is located based at least on an altitude component of the position fix;
obtaining structural data for the identified indoor environment;
and
determining a floor lower bound for the current location of the mobile device based on the altitude component and the structural data.

9 more elements

Dependencies are inferred from the claim text.

Three-dimensional city models and shadow mapping to improve altitude fixes in urban environments

Life of this patent

Three-dimensional city models and shadow mapping to improve altitude fixes in urban environments

Life of this patent

Abstract

Claims20