GPS/INS

About: GPS/INS is a research topic. Over the lifetime, 3554 publications have been published within this topic receiving 62784 citations.

Single global positioning system receiver capable of attitude determination

Abstract: A platform attitude determination can be made with a single receiver in a global positioning system (GPS). The receiver receives at least three sets of GPS signals from three antennas. Two of the GPS signals are delayed so that the receiver receives each GPS signal in separate time domain slots. In this way, the synchronization of separate GPS receivers does not have to be accomplished.

Enhancement of signal-detection capability of GPS systems

Abstract: Estimated Global Position System (GPS) navigation data is used to increase the signal integration interval. In one embodiment, a WAG (wireless assisted GPS) server receives GPS signals and demodulates the navigation data modulated onto the GPS signals. The WAG server utilizes known features of the demodulated navigation data to generate estimated navigation data for the satellite. This estimation can be made several seconds or even minutes ahead of time. The wireless terminal uses this estimated navigation data to perform a data wipe-off operation to enable the integration interval to be increased (e.g., beyond 20 ms), thereby increasing overall signal-detection sensitivity at the wireless terminal. In another embodiment, information from strong GPS signals is used to detect weak GPS signals from other satellites. In this embodiment, strong GPS signals are received directly by the wireless terminal from the satellites. After strong GPS signals have been detected, the strong GPS signals are demodulated to compute satellite ephemerides including navigation data. The demodulated navigation data is then matched with known features of the navigation data to estimate the navigation data for weak GPS signals. The estimated navigation data is then used to increase the integration interval for weak GPS signals so that weak GPS signals can also be detected at the wireless terminal.

Global positioning system roadside integrated precision positioning system

Abstract: A real-time integrated navigation system for a vehicle includes a GPS receiver, connected to a first antenna, where the GPS receiver receives GPS data from satellites and outputs GPS position data. The system also includes a communications link, connected to a second antenna and to the GPS receiver, receiving range and carrier phase measurements from at least one base station. The system further includes navigation aids which provide relative position data of said vehicle and a Kalman filter, connected to the output of the GPS receiver and the navigation aids, that integrates the GPS position data and the relative position data and outputs smoothed position data. The smoothed position data is used in transportation applications, especially detection of lane departure. This GPS-based positioning system is suitable for highway speeds during all weather conditions.

Attitude change kalman filter measurement apparatus and method

Abstract: A navigation system includes a Kalman filter to compensate for bias errors in inertial sensing elements. An observed pitch, roll or heading change is input to the Kalman filter either from an aiding source or when the navigation system is in a known condition. The Kalman filter generates a correction signal that is provided to the navigation computation system.

Non-GPS Navigation for Emergency Responders

Abstract: - This paper introduces a novel navigation system for walking persons The system is of particular benefit for emergency responders, who often have to enter and move around in large structures where GPS is unavailable We refer to our system as “Personal Odometry System” (POS) The POS measures the position of a walking person relative to a known starting position, such as the entrance to a building This is accomplished by instrumenting one boot of the subject with a 3-axis gyroscope and a 3-axis accelerometer (collectively called “inertial measurement unit” – IMU) This paper describes the POS hardware and explains the basics of our approach The paper also presents extensive experimental results, which illustrate the utility and practicality of our system I I NTRODUCTION This paper describes our Personal Odometry System (POS) for measuring and tracking the momentary location and trajectory of a walking person, even if GPS is not available We believe that such a system might be of particular value for emergency responders For example, fire fighters entering a burning building are at risk to be injured and unable to report their position With the POS reporting the user’s position to a central command post, each emergency responder’s location could be tracked in real-time Another application involves the “clearing” of a large building by emergency or security personnel Their challenge often is to keep track of rooms already cleared and areas that were not cleared, yet Our system’s ability to track each person’s location provides a useful solution for this problem Our proposed POS does not require GPS This is an important distinction, since GPS is not available indoors Furthermore, GPS is unreliable under dense foliage, in so-called “urban canyons,” and generally in any environment, in which a clear view of a good part of the sky is not available There are some approaches to personal position estimation without GPS Typically, these systems require external references, also called “fiducials,” such as preinstalled active beacons, receivers, or optical retroreflectors Common to all fiducial-based position estimation systems is that the fiducials must be installed in the work space at precisely surveyed locations before the system can be used This installation is time consuming and expensive, and in case of emergency response completely unfeasible Fiducial-based systems also require an active radiation source, such as infrared light [1], ultrasound [2], or magnetic fields [3], which may be undesirable in security-related applications Generally, fiducial-based systems perform well and are able to provide absolute position and orientation in real-time If the application permits the installation of fiducials ahead of time, then these systems have the significant advantage that errors don’t grow with time, as is the case in our POS Another way of implementing absolute position estimation is computer vision ([4] and [5]) Images are compared and matched against a pre-compiled database Computer vision has the advantage that the environment does not need to be modified, but the approach requires potentially very large databases Work is also being done on so-called Simultaneous Location and Mapping (SLAM) methods, which don’t require a precompiled database However, SLAM systems are not as reliable, may accrue errors over time and distance, and poor visibility and unfavorable light conditions can result in completely false position estimation [6][7] The scientific literature offers only very few approaches that do not require external references The simplest one of them is the pedometer, that is, a device that counts steps Pedometers must be calibrated for the stride length of the user and they produce large errors when the user moves in any other way than his or her normal walking pattern One commercially available personal navigation system based on this principle is the Dead Reckoning Module (DRM) by PointResearch [8] It uses accelerometers to identify steps, and linear displacement is computed assuming that the step size is constant Orientation is measured using a digital compass, which is combined with the traveled distance (step counts) to estimate 2-D position The performance of this system depends on the accuracy of determining the stride