Abstract: For global navigation satellite system (GNSS)-independent operation of auxiliary PNT systems, one or more ground stations of the auxiliary system have access to a non-GNSS source of precision timing. That source and known locations of the ground stations may be used to derive timing corrections to account for imperfect clocks in the satellites for non-purpose-built satellite systems being used for PNT. Crosslinks between satellites and/or propagation of timing correction through other ground stations are used to better control the timing and resulting precession of PNT in the PNT auxiliary system. The timing correction may be provided as a service to end users, other constellations, and/or other satellite operators.

Abstract: For validation of wireless signals, a wireless receiver receives a validation signal that includes information from a target signal. By using digital signature, message authentication code (MAC), and/or hashing, the validation signal is verified to be from a trusted source. By comparing the information from the verified validation signal with the target signal, the target signal is confirmed to be genuine or not a spoofing signal. In one approach, the validation signal is provided from a different transmission source than the target signal. In another approach, modulation estimation rather than known modulation is used as the information for the validation signal for comparison with the target signal despite not knowing the spread pattern of the coding. In yet another approach, a one-way function is used to generate a pseudorandom code to spread a first component of the a first signal below the noise floor. The input to the one-way function is a second component sent at a time later than the time.

Abstract: 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.

Abstract: Aspects of the disclosure relate to positioning, navigation, and timing (PNT) satellite beam and data scheduling. In one or more embodiments, a method for determining a location and/or time offset of at least one receiver involves transmitting, by at least one satellite, at least one beam, which is a sweeping beam. In one or more embodiments, each of the beams comprises at least one signal used for positioning, navigation, or timing. The method further comprises varying, by at least one satellite, aspects of at least one signal based on optimization parameters. In at least one embodiment, the optimization parameters comprise a location of a beam footprint of at least one beam. In one or more embodiments, at least one receiver receives at least one signal. In at least one embodiment, the location and/or the time offset of at least one receiver is determined by using at least one signal.

Abstract: For assisted satellite time and location (STL) in low earth orbit (LEO) and/or burst transmission-based STL, assistance is provided. Ephemeris information is provided to receivers of signals from LEO satellites, allowing the receivers to operate better in PNT based on the signals from the LEO satellites. Other information may be used to assist, such as terrestrial-based time and/or location of the receiver. For burst transmissions, the data (e.g., spread code) used for some or all the burst transmission is provided to the receiver, which may then replicate the signal. This replica signal assists in PNT based on the signals from the satellites transmitting the burst signals.

Abstract: For global navigation satellite system (GNSS)-independent operation of auxiliary PNT systems, one or more ground stations of the auxiliary system have access to a non-GNSS source of precision timing. That source and known locations of the ground stations may be used to derive timing corrections to account for imperfect clocks in the satellites for non-purpose-built satellite systems being used for PNT. Crosslinks between satellites and/or propagation of timing correction through other ground stations are used to better control the timing and resulting precession of PNT in the PNT auxiliary system. The timing correction may be provided as a service to end users, other constellations, and/or other satellite operators.

Abstract: 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.

Abstract: 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.

Abstract: A method for correcting for time delay variations between a plurality of signal paths from a signal source to at least one transmit antenna of a satellite may include measuring a time delay for each of the plurality of signal paths. The method may also include correcting a signal for the time delay variation based on the time delay for the signal path that is currently being used by the satellite, the corrected signal being usable for at least one of navigation, determining a geographic location and determining time.

Abstract: A device controller configured to control physical devices using an audible humming frequency that includes: a humming frequency module, a humming command module, and a control command module. The humming frequency module may be configured to determine humming frequenc(ies) using a detected humming signal(s). The humming command module may be configured to compute humming command(s) based on the humming frequenc(ies). The control command module may be configured to generate control command(s) using received key command(s) and humming command(s).

Abstract: A generalized high performance navigation system is provided using low earth orbit (LEO) satellites. In one embodiment, a method of performing navigation includes receiving a LEO signal from a LEO satellite. The method also includes decoding a navigation signal from the LEO signal. The method further includes receiving first and second ranging signals from first and second ranging sources, respectively. In addition, the method includes determining calibration information associated with the first and second ranging sources. The method also includes calculating a position using the navigation signal, the first and second ranging signals, and the calibration information.

Abstract: A low earth orbit (LEO) satellite data uplink is provided. In one embodiment, a method of providing a data uplink to a LEO satellite includes determining position information using a LEO signal received from the LEO satellite, a first ranging signal received from a first ranging source, and a second ranging signal received from a second ranging source. The method also includes determining a timing advance parameter using a local clock reference and a LEO satellite clock reference. The method further includes preparing a data uplink signal comprising uplink data to be broadcast to the LEO satellite. In addition, the method includes synchronizing the data uplink signal with the LEO satellite using the timing advance parameter. The method also includes broadcasting the data uplink signal to the LEO satellite.

Abstract: Low earth orbit (LEO) satellites are used to provide navigation signals. In one embodiment, a method of providing a LEO signal from a LEO satellite includes providing a plurality of transmit channels over a plurality of transmit slots. The transmit channels comprise a set of communication channels and a set of navigation channels. The method also includes generating a first pseudo random noise (PRN) ranging overlay corresponding to a navigation signal. The method further includes applying the first PRN ranging overlay to a first set of the navigation channels. In addition, the method includes combining the communication channels and the navigation channels into a LEO signal. The method also includes broadcasting the LEO signal from the LEO satellite.

Abstract: This invention describes a means for acquiring GPS P/Y code under jamming conditions. It improves jam resistance by augmenting a component of the GPS signal with one from a different satellite system, such as a low earth orbiting (LEO) satellite. The preferred embodiment of this invention employs the Iridium LEO satellite constellation broadcasting in a 10 MHz wide band about 1,621 MHz. A low-cost, integrated Iridium receiver coupled to the GPS receiver employs a single antenna that is capable of receiving both the GPS and Iridium signals together.

Abstract: A low-cost, solid-state position sensor system suitable for making precise code and carrier phase measurements in the L1 and L2 bands of GPS uses an ordinary, low-cost OEM card single-frequency carrier phase tracking C/A code receiver and includes low-cost hardware for sensing the L1 and L2 components of GPS carrier phase. Such measurements are suitable for general use in a variety of fields, including surveying. They are also of sufficient quality to be used in controlling heavy machinery, such as aircraft, farm tractors, and construction and mining equipment. A C/A code continuous tracking GPS receiver is used to produce GPS positioning fixes and real-time L1 carrier phase measurements. This C/A code receiver generates timing and reference information for a digital sampling component. This sampling component processes the L1 and L2 signals from the GPS signals in view.

Abstract: A low-cost, solid-state position sensor system suitable for making precise code and carrier phase measurements in the L1 and L2 bands of GPS uses an ordinary, low-cost OEM card single-frequency carrier phase tracking C/A code receiver and includes low-cost hardware for sensing the L1 and L2 components of GPS carrier phase. Such measurements are suitable for general use in a variety of fields, including surveying. They are also of sufficient quality to be used in controlling heavy machinery, such as aircraft, farm tractors, and construction and mining equipment. A C/A code continuous tracking GPS receiver is used to produce GPS positioning fixes and real-time L1 carrier phase measurements. This C/A code receiver generates timing and reference information for a digital sampling component. This sampling component processes the L1 and L2 signals from the GPS signals in view.

Abstract: A low-cost, solid-state position sensor system suitable for making precise code and carrier phase measurements in the L1 and L2 bands of GPS uses an ordinary, low-cost OEM card single-frequency carrier phase tracking C/A code receiver and includes low-cost hardware for sensing the L1 and L2 components of GPS carrier phase. Such measurements are suitable for general use in a variety of fields, including surveying. They are also of sufficient quality to be used in controlling heavy machinery, such as aircraft, farm tractors, and construction and mining equipment. A C/A code continuous tracking GPS receiver is used to produce GPS positioning fixes and real-time L1 carrier phase measurements. This C/A code receiver generates timing and reference information for a digital sampling component. This sampling component processes the L1 and L2 signals from the GPS signals in view.

Abstract: A low-cost, solid-state position sensor system suitable for making precise code and carrier phase measurements in the L1 and L2 bands of GPS uses an ordinary, low-cost OEM card single-frequency carrier phase tracking C/A code receiver and includes low-cost hardware for sensing the L1 and L2 components of GPS carrier phase. Such measurements are suitable for general use in a variety of fields, including surveying. They are also of sufficient quality to be used in controlling heavy machinery, such as aircraft, farm tractors, and construction and mining equipment. A C/A code continuous tracking GPS receiver is used to produce GPS positioning fixes and real-time L1 carrier phase measurements. This C/A code receiver generates timing and reference information for a digital sampling component. This sampling component processes the L1 and L2 signals from the GPS signals in view.