A method of and a receiver for mitigating multipath interference in a global navigation satellite system. In accordance with an embodiment, GNSS signals are received from a plurality of satellites in at least two frequency bands. A likelihood indicator is determined which is indicative of how likely the received GNSS signals are affected by multipath interference. In response to the likelihood indicator, all GNSS signals from at least one frequency band of the at least two frequency bands are discounted. The received GNSS signals are processed by taking into account said discounting of all GNSS signals in the at least one frequency band. The discounting may include assigning less weight to the discounted frequency bands or disregarding each of the discounted frequency bands in their entirety.

A method of and a receiver for mitigating multipath interference in a global navigation satellite system. In accordance with an embodiment, GNSS signals are received from a plurality of satellites in at least two frequency bands. A likelihood indicator is determined which is indicative of how likely the received GNSS signals are affected by multipath interference. In response to the likelihood indicator, all GNSS signals from at least one frequency band of the at least two frequency bands are discounted. The received GNSS signals are processed by taking into account said discounting of all GNSS signals in the at least one frequency band. The discounting may include assigning less weight to the discounted frequency bands or disregarding each of the discounted frequency bands in their entirety.

Disclosed are techniques for navigating a mobile machine, such as an autonomous robot, in an environment that includes objects that may block, reflect, or distort satellite signals to be used for positioning. Satellite data may be captured from one or more satellites. An image may be captured using an imaging device that is at least partially oriented toward the one or more satellites. A set of sky scores may be calculated for a set of ground positions surrounding the mobile machine based on the satellite data and the image. Each of the set of sky scores may be indicative of an accuracy of a satellite-based position at one of the set of ground positions. The mobile machine's navigation may be modified using the set of sky scores.

A method for navigating a carrier using a Kalman filter estimating a navigation state of a carrier, comprising: obtaining, from a signal transmitted by the satellite and subsequently received by the carrier, a delta range measured between the carrier and a satellite and another measured kinematic datum which is associated with the satellite, generating, from position data for the carrier and the satellite in the navigation state, an estimated delta range between the carrier and the satellite, calculating, using the delta ranges, a delta range innovation associated with the satellite, carrying out a test on the delta range innovation, the test result indicating whether or not the signal was a multi-path signal, using, by means of the filter, the kinematic datum as an observation to update the navigation state provided that the test result indicates that the signal was not a multi-path signal.

A method for navigating a carrier using a Kalman filter estimating a navigation state of a carrier, comprising: obtaining, from a signal transmitted by the satellite and subsequently received by the carrier, a delta range measured between the carrier and a satellite and another measured kinematic datum which is associated with the satellite, generating, from position data for the carrier and the satellite in the navigation state, an estimated delta range between the carrier and the satellite, calculating, using the delta ranges, a delta range innovation associated with the satellite, carrying out a test on the delta range innovation, the test result indicating whether or not the signal was a multi-path signal, using, by means of the filter, the kinematic datum as an observation to update the navigation state provided that the test result indicates that the signal was not a multi-path signal.

A complex and intricate GNSS antenna that is created using inexpensive manufacturing techniques is disclosed. The antenna combines a loop antenna and a cross dipole antenna together, in a single plane, to create an optimal GNSS gain pattern. The antenna structure is symmetric and right-hand circular polarized to force correct polarization over a wide range of frequency and beamwidth. The feed structure is part of the antenna radiating element.

Methods, systems, computer-readable media, and apparatuses for determination of multipath for determining a location of user equipment (UE) are presented. In some embodiments, the UE may, based on a first indication of signal strength associated with a first polarization type, and a second indication of signal strength associated with a second polarization type, determine an indication of multipath reflection along a path of signal propagation between a space vehicle (e.g., GNSS satellite) and the UE. Circularly polarized positioning signals may be received by the UE via natively present linearly polarized antennas and converted into circularly polarized signals. Converted circularly polarized signals may include right-handed and left-handed components, and signal strengths for each component may be compared to determine the presence of multipath. Positioning signals may be given a weight or disregarded based on the multipath determination when determining the position of the UE.

Methods, systems, computer-readable media, and apparatuses for determination of multipath for determining a location of user equipment (UE) are presented. In some embodiments, the UE may, based on a first indication of signal strength associated with a first polarization type, and a second indication of signal strength associated with a second polarization type, determine an indication of multipath reflection along a path of signal propagation between a space vehicle (e.g., GNSS satellite) and the UE. Circularly polarized positioning signals may be received by the UE via natively present linearly polarized antennas and converted into circularly polarized signals. Converted circularly polarized signals may include right-handed and left-handed components, and signal strengths for each component may be compared to determine the presence of multipath. Positioning signals may be given a weight or disregarded based on the multipath determination when determining the position of the UE.

A transceiver system and methodology generate, monitor and detect changes in Global Navigation Satellite System (GNSS) interferometric reflectometry signatures as to provide defensive security for GNSS signals used for positioning, navigating, and timing applications.

A method includes: receiving one or more positioning signals; determining that a UE is line-of-sight to fewer than a threshold number of positioning signal sources; determining a first position estimate hypothesis for the UE using a first position estimating process and one or more first measurements of the positioning signal(s); determining a second position estimate hypothesis for the UE using a second position estimating process and one or more second measurements of the positioning signal(s), wherein the second position estimating process uses a second parameter value of a parameter and the parameter is absent from the first position estimating process or has a first parameter value that is different from the second parameter value; and reporting a reported position estimate based on the first position estimate hypothesis or the second position estimate hypothesis in response to the UE being line-of-sight to fewer than the threshold number of positioning signal sources.