A test installation for simulating multiple reflections of GNSS signals, the installation including a bottom screen that is reflective in the radio frequency spectrum; a top screen above the bottom screen, wherein the top screen is partly transparent in a radio frequency spectrum, and wherein the top screen is substantially dome-shaped and has a height of 1 to 3 meters; and a GNSS antenna between the top screen and the bottom screen; wherein the test installation is configured to measure the GNSS signals received by the antenna and to simulate the multipath reflections.

Power can be preserved in a tracking device equipped with a GPS receiver and a transceiver by evaluating the proximity of the tracking device to a mobile device and enabling the GPS receiver and transceiver only in the event that the tracking device is out of the range of the mobile device. Once enabled, the location of the tracking device can be determined based on location information received from the GPS receiver. The determined location can be provided to a tracking system associated with the tracking device. The tracking system can then inform an owner of the tracking device of the determined location. Once the tracking device has been found, the GPS receiver and the transceiver can be disabled to save additional power.

Power can be preserved in a tracking device equipped with a GPS receiver and a transceiver by evaluating the proximity of the tracking device to a mobile device and enabling the GPS receiver and transceiver only in the event that the tracking device is out of the range of the mobile device. Once enabled, the location of the tracking device can be determined based on location information received from the GPS receiver. The determined location can be provided to a tracking system associated with the tracking device. The tracking system can then inform an owner of the tracking device of the determined location. Once the tracking device has been found, the GPS receiver and the transceiver can be disabled to save additional power.

Techniques for determining whether data associated with an autonomous operation of a first unmanned vehicle may be trusted. For example, the first unmanned vehicle may receive an indication related to the data and originating from a second unmanned vehicle over a network. For instance, the indication may indicate that similar data for a similar autonomous operation of the second unmanned vehicle may be untrusted. Based on a level of trust accorded to the indication, the first unmanned vehicle may determine that the data may be untrusted and the autonomous navigation may be directed independently of the data.

Disclosed is an on-board backup and anti-spoofing GPS (“OBASG”) system for navigating a vehicle through an environment with a GPS receiver. The GPS receiver is configured to receive GPS signals within the environment where the GPS signals may suffer a GPS outage or are unreliable within the environment. In general, the OBASG includes a GPS block-chain recorder, a block-chain storage module, an anti-spoofing module, and a backup navigation module.

For validation of position, navigation, time (PNT) signals, a hash included in messages with PNT data is used to validate the source of the message without backhaul. Different tags from a hash chain are included in different messages. The receiver is pre-loaded with the root or later trusted hash tag of the chain as created. The hash of any received message may be hashed by the receiver. The result of the hashing will match the pre-loaded or trusted hash tag if the transmitter of the message is a valid source. The PNT data may be validated using a digital signature formed from the PNT data for one or more messages and the hash tag wherein a hash tag of the chain in a subsequently received message is used as the key. The digital signature may be formed from data across multiple messages.

For validation of position, navigation, time (PNT) signals, a hash included in messages with PNT data is used to validate the source of the message without backhaul. Different tags from a hash chain are included in different messages. The receiver is pre-loaded with the root or later trusted hash tag of the chain as created. The hash of any received message may be hashed by the receiver. The result of the hashing will match the pre-loaded or trusted hash tag if the transmitter of the message is a valid source. The PNT data may be validated using a digital signature formed from the PNT data for one or more messages and the hash tag wherein a hash tag of the chain in a subsequently received message is used as the key. The digital signature may be formed from data across multiple messages.

A wireless device for indoor positioning has a satellite positioning system, a transceiver, a motion measurement system, and a position estimation system. The satellite positioning system is configured to determine a location of the device based on received satellite positioning signals. The wireless local area network transceiver is configured to measure while in the areas of non-reception, signals transmitted by wireless local area network (WLAN) access points (APs). The motion measurement system is configured to measure movement of the wireless device. The position estimation system is configured to determine a reference location, and record measurements of movement. The reference location and the recorded measurements are to be provided to a positioning database that generates a positioning grid.

A wireless device for indoor positioning has a satellite positioning system, a transceiver, a motion measurement system, and a position estimation system. The satellite positioning system is configured to determine a location of the device based on received satellite positioning signals. The wireless local area network transceiver is configured to measure while in the areas of non-reception, signals transmitted by wireless local area network (WLAN) access points (APs). The motion measurement system is configured to measure movement of the wireless device. The position estimation system is configured to determine a reference location, and record measurements of movement. The reference location and the recorded measurements are to be provided to a positioning database that generates a positioning grid.

A positioning system having an onboard positioning device and a roadside device is provided. The onboard positioning device receives a plurality of first positioning signals and records a positioning moving locus of a vehicle according to the first positioning signals. The roadside device detects a real moving locus of the vehicle. The onboard positioning device obtains the real moving locus from the roadside device, and calculates a positioning calibration value according to coordinates of the positioning moving locus and coordinates of the real moving locus. Furthermore, the onboard positioning device receives a plurality of second positioning signals and calculates and outputs a plurality of calibrated positioning coordinates according to the second positioning signals and the positioning calibration value.