Abstract: A method for time-space-position-information (TSPI) for at least one air-based platform in a flight test includes providing a system having components to collect TSPI. The system, which includes an air-based platform, is initialized and a flight test is started. The system is remotely monitored to determine system diagnostics and, when system problems are diagnosed, they are fixed by remote configuration or manual repair. TSPI data is received with ground-based receiver nodes through a wireless data link signal transmitted from a dedicated on board transmitter on the air-based platform. The dedicated on board transmitter uses a known transmitter signal waveform. The ground-based receiver nodes match an internally generated signal waveform to the known transmitter signal waveform to measure time of arrival. The TSPI data is collected and sent to a ground processing station. The TSPI data is processed with the ground processing station. The system components and TSPI data are collected.

Abstract: A system and method for time-space-position-information (TSPI) includes at least one air-based platform having an on-board navigation system. The on-board navigation system includes a dedicated on-board transmitter and a dedicated on-board receiver. A plurality of ground-based receiver nodes are in communication with the on-board transmitter of the air-based platform. A plurality of ground-based pseudolite transmitter nodes are in communication with the on-board receiver of the air-based platform. The system can provide TSPI solutions for the air-based platform during range and field testing. A ground-based station controls and monitors system components and processes data.

Abstract: An improved approach to satellite-based navigation (e.g., GPS) is provided. In one embodiment, a method includes receiving a first set of tracking information. A nominal orbital path for the navigation satellite is determined using the first set of tracking information. Ephemeris data corresponding to the nominal orbital path is computed and uploaded to the navigation satellite. Long-term navigation information corresponding to the nominal orbital path is transmitted to a communication system for broadcast to a plurality of navigation devices. A second set of tracking information is received, an orbital path of the navigation satellite using the second set of tracking information is predicted, and a difference between the predicted orbital path and the nominal orbital path is determined. Commands configured to instruct the navigation satellite to adjust an actual orbital path of the navigation satellite to substantially conform to the nominal orbital path are uploaded to the navigation satellite.

Abstract: An improved approach to satellite-based navigation (e.g., GPS) is provided. In one embodiment, a method includes determining a nominal orbital path of a navigation satellite. The method also includes transmitting ephemeris data corresponding to the nominal orbital path from the navigation satellite to a plurality of navigation devices. The method further includes determining an actual orbital path of the navigation satellite locally at the navigation satellite. In addition, the method includes determining a deviation between the actual orbital path and the nominal orbital path locally at the navigation satellite. The method also includes autonomously adjusting the actual orbital path locally at the navigation satellite to reduce the deviation between the actual orbital path and the nominal orbital path.

Abstract: A method and system for enabling a more robust detection, acquisition and positioning solution capability for a GPS device. The system and method uses GPS satellite ranging signals based on a simultaneous, all-in-view coherent PRN code signal processing scheme, rather than acquisition of GPS signals one at a time, in order to predict a location of a GPS user receiver. Additionally, image processing techniques, ultra-tight coupling processing techniques, or a combination thereof, are used to further enhance accuracy in determining the location of the user receiver. Signal processing techniques are used to determine the location of the GPS user receiver when no GPS satellite ranging signals can be individually detected, or when only one or two strong GPS satellite ranging signals can be individually detected in weak signal environments, jamming conditions, and a combination thereof.

Abstract: A GNSS ultra-tight coupling (UTC) receiver architecture applicable to space borne orbit platforms is described. A receiver in accordance with this architecture retains the rotational motion sensors typically found in an inertial measurement unit (IMU) of a conventional UTC receiver, but replaces the IMU accelerometer sensors with precise orbital dynamics models to predict the translational motion of the platform center of gravity (CG). Drag and radiation pressure may be modeled as well. The various models can be implemented in software. The IMU rotational sensors are retained for compensation of the GNSS antenna lever arm effect due to platform rotation.

Abstract: A method and system for enabling more robust detection, positioning and time solution using GPS satellite ranging signals based on a simultaneous, all-in-view coherent PRN code signal processing scheme rather than acquisition of GPS signals one at a time. Additionally, a plurality of signal processing operating modes are provided that include a Factory Start mode, a Hot Start mode, a Subsequent Fix mode and a Reacquisition mode. Each mode provides a user receiver with an ability to quickly determine its current probable location without undue delay when a prior probable location has been obtained. Preventing undue delay of predicting a probable location of the user can be especially valuable in conditions where weak signals are being received, or in high interference environments, or when signal jamming conditions are being experienced, or when a combination of such environments is present.

Abstract: A method and system for enabling more robust detection, positioning and time solution using GPS satellite ranging signals based on a simultaneous, all-in-view coherent PRN code signal processing scheme rather than acquisition of GPS signals one at a time. Additionally, a plurality of signal processing operating modes are provided that include a Factory Start mode, a Hot Start mode, a Subsequent Fix mode and a Reacquisition mode. Each mode provides a user receiver with an ability to quickly determine its current probable location without undue delay when a prior probable location has been obtained. Preventing undue delay of predicting a probable location of the user can be especially valuable in conditions where weak signals are being received, or in high interference environments, or when signal jamming conditions are being experienced, or when a combination of such environments is present.

Abstract: A method and system of the present disclosure allow for a more robust detection of GPS satellite ranging signals based on a simultaneous, all-in-view coherent PRN code signal processing scheme rather than acquisition of GPS signals one at a time. Additionally, the method and system may enable 10 dB or more improvement in signal-to-ratio (SNR) acquisition performance of the combined signals when compared to conventional acquisition approaches of acquiring GPS PRN code signals one at a time. The method and system also automatically enables removal of ranging errors common to both the user and base station and minimizes the introduction of multi-path errors into code phase measurements.

Abstract: A method and system for enabling a more robust detection, acquisition and positioning solution capability for a GPS device. The system and method uses GPS satellite ranging signals based on a simultaneous, all-in-view coherent PRN code signal processing scheme, rather than acquisition of GPS signals one at a time, in order to predict a location of a GPS user receiver. Additionally, image processing techniques, ultra-tight coupling processing techniques, or a combination thereof, are used to further enhance accuracy in determining the location of the user receiver. Signal processing techniques are used to determine the location of the GPS user receiver when no GPS satellite ranging signals can be individually detected, or when only one or two strong GPS satellite ranging signals can be individually detected in weak signal environments, jamming conditions, and a combination thereof.

Abstract: User equipment navigation solution with position determination of a navigation signal reflector methods and systems are described. In an embodiment, navigation signals transmitted from global positioning system (GPS) platform(s) can be received at a GPS-enabled receiver as direct navigation signals and reflected navigation signals. The direct navigation signals can then be isolated from the reflected navigation signals. Receiver range measurements can be determined from the direct navigation signals which are received via direct signal paths from the GPS platform(s), and a navigation solution of the GPS-enabled receiver can then be resolved from the receiver range measurements. Similarly, reflector range measurements can be determined from the reflected navigation signals which are received via reflected signal paths from a signal reflector, and a position of the signal reflector can then be resolved from the reflector range measurements at the GPS-enabled receiver.

Abstract: An improved approach to satellite-based navigation (e.g., GPS) is provided. In one embodiment, a method includes determining a nominal orbital path of a navigation satellite. The method also includes transmitting ephemeris data corresponding to the nominal orbital path from the navigation satellite to a plurality of navigation devices. The method further includes determining an actual orbital path of the navigation satellite locally at the navigation satellite. In addition, the method includes determining a deviation between the actual orbital path and the nominal orbital path locally at the navigation satellite. The method also includes autonomously adjusting the actual orbital path locally at the navigation satellite to reduce the deviation between the actual orbital path and the nominal orbital path.

Abstract: A system and method for determining the attitude of a platform is provided. The method includes: (a) Searching and scanning for one or more GPS satellite(s) to determine initial platform position; wherein a single directionally steered antenna scans for the GPS/GNSS satellite; (b) pointing and scanning the antenna to GPS/GNSS satellite to determine a first angular measurement of a direction of a GPS/GNSS signal; (c) measuring carrier to noise ratio of the GPS/GNSS satellite; (d) dithering the single directionally steered antenna to obtain an angular measurement relative to an antenna pattern bore-sight reference; (e) repeating steps (b)-(d) to determine a second angular measurement of the direction of a second GPS signal; (f) determining the attitude error of the platform using the first and second angular measurements; (g) updating the platform position and attitude.

Abstract: An improved approach to satellite-based navigation (e.g., GPS) is provided. In one embodiment, a method includes receiving a first set of tracking information. A nominal orbital path for the navigation satellite is determined using the first set of tracking information. Ephemeris data corresponding to the nominal orbital path is computed and uploaded to the navigation satellite. Long-term navigation information corresponding to the nominal orbital path is transmitted to a communication system for broadcast to a plurality of navigation devices. A second set of tracking information is received, an orbital path of the navigation satellite using the second set of tracking information is predicted, and a difference between the predicted orbital path and the nominal orbital path is determined. Commands configured to instruct the navigation satellite to adjust an actual orbital path of the navigation satellite to substantially conform to the nominal orbital path are uploaded to the navigation satellite.

Abstract: A GNSS ultra-tight coupling (UTC) receiver architecture applicable to space borne orbit platforms is described. A receiver in accordance with this architecture retains the rotational motion sensors typically found in an inertial measurement unit (IMU) of a conventional UTC receiver, but replaces the IMU accelerometer sensors with precise orbital dynamics models to predict the translational motion of the platform center of gravity (CG). Drag and radiation pressure may be modeled as well. The various models can be implemented in software. The IMU rotational sensors are retained for compensation of the GNSS antenna lever arm effect due to platform rotation.

Abstract: User equipment navigation solution with position determination of a navigation signal reflector methods and systems are described. In an embodiment, navigation signals transmitted from global positioning system (GPS) platform(s) can be received at a GPS-enabled receiver as direct navigation signals and reflected navigation signals. The direct navigation signals can then be isolated from the reflected navigation signals. Receiver range measurements can be determined from the direct navigation signals which are received via direct signal paths from the GPS platform(s), and a navigation solution of the GPS-enabled receiver can then be resolved from the receiver range measurements. Similarly, reflector range measurements can be determined from the reflected navigation signals which are received via reflected signal paths from a signal reflector, and a position of the signal reflector can then be resolved from the reflector range measurements at the GPS-enabled receiver.

Abstract: A system and method for determining the attitude of a platform is provided. The method includes: (a) Searching and scanning for one or more GPS satellite(s) to determine initial platform position; wherein a single directionally steered antenna scans for the GPS/GNSS satellite; (b) pointing and scanning the antenna to GPS/GNSS satellite to determine a first angular measurement of a direction of a GPS/GNSS signal; (c) measuring carrier to noise ratio of the GPS/GNSS satellite; (d) dithering the single directionally steered antenna to obtain an angular measurement relative to an antenna pattern bore-sight reference; (e) repeating steps (b)-(d) to determine a second angular measurement of the direction of a second GPS signal; (f) determining the attitude error of the platform using the first and second angular measurements; (g) updating the platform position and attitude.