Patent application number | Description | Published |
20080234933 | Systems and Methods for Detecting a Vehicle Static Condition - Systems and methods for detecting a vehicle static condition are provided. In this regard, a representative system includes a sensor operative to detect at least one of acceleration and angular rate of a vehicle. The sensor is further operative to generate a vehicle vibration profile based on the at least one of the detected acceleration and angular rate of the vehicle. The system further includes a computing device operative to receive the vehicle vibration profile from the sensor, the computing device being further operative to determine whether the vehicle is stationary or moving based on the vehicle vibration profile. A representative method for detecting a vehicle static condition includes detecting at least one of acceleration and angular grade of a vehicle; generating a vehicle vibration profile based on at least one of the detected acceleration and angular grade of the vehicle; receiving the vehicle vibration profile; and determining whether the vehicle is stationary or moving based on the vehicle vibration profile. | 09-25-2008 |
20080246653 | GPS NAVIGATION USING INTERACTING MULTIPLE MODEL (IMM) ESTIMATOR AND PROBABILISTIC DATA ASSOCIATION FILTER (PDAF) - A method for GPS navigation which uses an interacting multiple-model (IMM) estimator with a probabilistic data association filter (PDAF) improves navigation performance. The method includes (a) providing two or more models of GPS navigation, with each model characterized by a model state vector which is updated periodically, (b) providing for each model a corresponding filter for deriving, for each period, a current value for the corresponding model state vector based on current measurements made on parameters affecting the corresponding state vector; and (c) applying an interacting multiple model (IMM) estimator to provide, for each period, a current value for a system state vector using the current values of the model state vectors for that period and their corresponding filters. Each model state vector may include one or more of the following: variables: 3-dimensional position, 3-dimensional velocity, satellite clock bias, satellite clock drifts and one or more other satellite parameters. The current value of the system state vector may be a weighted average of the current values of the model state vectors, where the weights are a set of mode probabilities. In addition, one or more of the filters is a probabilitic data association filter (PDAF). | 10-09-2008 |
20080309553 | Systems and Methods for Mitigating Multipath Signals - Systems and methods for mitigating multipath signals in a receiver are provided. In this regard, a representative system, among others, includes a receiver comprising an antenna being configured to receive signals from a plurality of satellites, and a computing device being configured to: generate pseudorange measurements based on the received satellites signals, process the generated pseudorange measurements to reduce its pseudorange residuals based on statistical modeling in order to mitigate multipath errors, and compute navigation solutions based on the processed pseudorange measurements. A representative method, among others, for mitigating multipath signals in a receiver, comprises: receiving the pseudorange measurements; processing the received pseudorange measurements to reduce its pseudorange residuals based on statistical modeling in order to mitigate multipath errors; and computing navigation solutions based on the processed pseudorange measurements. | 12-18-2008 |
20090119015 | Systems and Methods for Processing Navigational Solutions - Systems and methods for processing navigational solutions are provided. In this regard, a representative system includes a navigational computing device comprising a processor and memory that stores a navigational solution manager that is executed by the processor to provide a receiver position. The navigational solution manager is configured to collect navigational data from at least one satellite vehicle, compute initialization navigational measurements based on the collected navigational data, and compute the receiver position using the initialization navigation measurements. | 05-07-2009 |
20090128407 | Systems and Methods for Detecting GPS Measurement Errors - Systems and methods for detecting global positioning system (GPS) measurement errors are provided. In this regard, a representative system, among others, includes a navigation device that is configured to receive GPS signals from signal sources, the navigation device being configured to calculate pseudoranges (PRs) and delta ranges (DRs) based on the received GPS signals, the navigation device including a consistency check algorithm that is configured to: determine mismatches between the respective calculated PRs and DRs, and indicate that an error exists in the respective calculated PRs and DRs based on their mismatch and mismatch accumulations. This algorithm can be independent of navigation state and is capable of detecting slow-changing errors. | 05-21-2009 |
20090195446 | System and Method for Verifying Consistent Measurements in Performing GPS Positioning - Systems and methods are provided for verifying whether a set of satellite signals may be used to calculate an estimated position. Example systems and methods may include a GPS receiver for receiving the satellite signals and a measurement consistency verifier to analyze a geometric configuration of the satellites from which the satellite signals were acquired. The measurement consistency verifier may determine if the satellites are sufficiently close to one another to provide consistent measurements. | 08-06-2009 |
20090254275 | Systems and Methods for Monitoring Navigation State Errors - Systems and methods for monitoring navigation state errors are provided. In this regard, a representative system, among others, includes a receiver that is configured to receive GPS signals and calculate pseudorange (PR) residuals, the receiver including a navigation state error manager that is configured to: calculate a distance traveled by the receiver having the PR residuals, determine whether a navigation state has errors based on the calculated PR residuals and calculated distance, and responsive to determining that the navigation state has errors, send an error message indicating that the navigation state has errors. | 10-08-2009 |
20100232351 | UTILIZING SBAS SIGNALS TO IMPROVE GNSS RECEIVER PERFORMANCE - The present invention provides methods of improving GNSS receivers' satellite signal acquisition and TIFF performances by taking advantage of SBAS signals. Due to a SBAS satellite's geostationary position and typically strong signal, the SBAS satellite signal can be acquired more quickly than a GPS satellite signal. Once a SBAS satellite signal is acquired the Doppler frequency search uncertainty may be reduced for remaining GNSS satellites which are to be acquired. Furthermore, a satellite search list may be optimized to search for satellites close to the line of sight (LOS) of the SBAS satellite for which a signal has been acquired, in receiver “warm” and “hot” start modes. Moreover, since a SBAS signal sub-frame is only one second long, which is shorter than six seconds for a GPS signal sub-frame, synchronization of the SBAS signal sub-frame may be achieved faster than for GPS signals. With aided time information, a receiver may compute the absolute time of week (TOW) from a sub-frame synchronized SBAS signal. Therefore, without necessarily waiting for TOW to be decoded from a GPS signal and with TOW extracted from a SBAS signal, a receiver can achieve better TTFF performance. | 09-16-2010 |
20100328146 | Systems and Methods for Synthesizing GPS Measurements to Improve GPS Location Availability - There are situations where GPS signals are received from less than four satellites. In order to improve the GPS location availability, disclosed here are systems and methods for synthesizing GPS measurements, which, together with fewer than four available real GPS signals, can be used to calculate a position fix. In particular, GPS range measurements for lost satellites, which are satellites that were previously tracked but are now not tracked, are synthesized to improve GPS signal availability. The synthesized measurements are used along with real measurements to enable accurate position fix even when GPS satellite availability is poor. Different synthesized measurement generation schemes, depending on whether an INS/DR aiding system is available, are further described herein. | 12-30-2010 |
20110025559 | METHOD AND APPARATUS FOR USING GPS SATELLITE STATE COMPUTATIONS IN GLONASS MEASUREMENT PROCESSING - The present invention is related to location positioning systems, and more particularly, to a method and apparatus for using satellite state information from two or more different satellite systems in navigation processing. According to one aspect, it makes use of GPS extended ephemeris functionality to produce satellite state vector estimates for GLONASS satellites. These satellite state vector estimates can be used alone or in combination with GPS satellite vectors to provide updates to the receiver's navigation processing. According to further aspects, the GLONASS satellite position and trajectory information is extrapolated with a GPS gravity model rather than the GLONASS model, thereby allowing it to be extrapolated more accurately and for longer periods of time than the GLONASS model allows. | 02-03-2011 |
20110184645 | USE OF ACCELEROMETER ONLY DATA TO IMPROVE GNSS PERFORMANCE - The present invention provides apparatus and methods for improving satellite navigation by assessing the dynamic state of a platform for a satellite navigation receiver and using this data to improve navigation models and satellite tracking algorithms. The dynamic state of the receiver platform may be assessed using only accelerometer data, and does not require inertial navigation system integration. The accelerometers may not need to be very accurate and may not need to be aligned and/or accurately calibrated. A method of accelerometer assisted satellite navigation may comprise: detecting a stationary condition of an accelerometer set; gross-calibrating the accelerometer set when in the stationary condition, wherein gross-calibrating includes determining a combined-bias of the accelerometer set; defining at least two acceleration levels using the combined-bias; collecting accelerometer data; categorizing the accelerometer data into one of the acceleration levels; and utilizing the categorized accelerometer data to enhance satellite navigation. | 07-28-2011 |
20110257885 | METHOD AND APPARATUS FOR GEOGRAPHICALLY AIDING NAVIGATION SATELLITE SYSTEM SOLUTION - The present invention is related to position calculation and navigation systems, and more particularly, to a method and apparatus for making accuracy improvements to a GPS receiver's navigation solutions. According to a first aspect, selective cartography information from a map database accessed by a GPS receiver from a location-aiding device is integrated into the position calculations performed by the GPS receiver. According to another aspect, selective cartography information includes indices representing associated attributes of geographical objects, such as, a width-indicator index for a road segment. | 10-20-2011 |
20120188121 | SYSTEMS AND METHODS FOR SYNTHESIZING GPS MEASUREMENTS TO IMPROVE GPS LOCATION AVAILABILITY - There are situations where GPS signals are received from less than four satellites. In order to improve the GPS location availability, disclosed here are systems and methods for synthesizing GPS measurements, which, together with fewer than four available real GPS signals, can be used to calculate a position fix. In particular, GPS range measurements for lost satellites, which are satellites that were previously tracked but are now not tracked, are synthesized to improve GPS signal availability. The synthesized measurements are used along with real measurements to enable accurate position fix even when GPS satellite availability is poor. Different synthesized measurement generation schemes, depending on whether an INS/DR aiding system is available, are further described herein. | 07-26-2012 |
20130069821 | Method and Apparatus of Using Height Aiding From a Contour Table for GNSS Positioning - The present invention is related to location positioning systems, and more particularly, to a method and apparatus for making accuracy improvements to a GPS receiver's navigation calculations. According to a first aspect, the invention includes maintaining a table of height attributes for major cities and urban areas around the world (contour table) in the GNSS chipset. The information in the table preferably includes latitude, longitude of the city along with height attributes of those cities, such as the average, min, max height and region boundary etc. Additional information such as average gradient could also be saved in the table. According to further aspects, when GPS signals are degraded in environments such as urban canyons, the height information can be obtained from the table and used to improve the navigation solution. | 03-21-2013 |
20130282276 | GNSS Performance Enhancement Using Accelerometer-Only Data - The present invention provides apparatus and methods for improving satellite navigation by assessing the dynamic state of a platform for a satellite navigation receiver and using this data to improve navigation models and satellite tracking algorithms. The dynamic state of the receiver platform may be assessed using only accelerometer data, and does not require inertial navigation system integration. The accelerometers may not need to be very accurate and may not need to be aligned and/or accurately calibrated. | 10-24-2013 |
20130321202 | Methods and Apparatuses for Multipath Estimation and Correction in GNSS Navigation Systems - The present invention relates generally to methods and apparatuses for estimating and correcting for multipath in GNSS navigation systems. According to some aspects, the invention takes advantage of situations where position and estimated position error are reasonably stable so as to detect when large multipath errors are present with confidence. After detection, the slowly varying biases from multipath or other un-modeled sources can be modeled separately from the navigation state. This makes it possible to keep the measurements in the solution without biasing the navigation state and further ignores the long-term biases for use over short-term periods with minimized pseudorange error when necessary. | 12-05-2013 |
20140292572 | UTILIZING SBAS SIGNALS TO IMPROVE GNSS RECEIVER PERFORMANCE - The present invention provides methods of improving GNSS receivers' satellite signal acquisition and TTFF performances by taking advantage of SBAS signals. Due to a SBAS satellite's geostationary position and typically strong signal, the SBAS satellite signal can be acquired more quickly than a GPS satellite signal. Once a SBAS satellite signal is acquired the Doppler frequency search uncertainty may be reduced for remaining GNSS satellites which are to be acquired. Furthermore, a satellite search list may be optimized to search for satellites close to the line of sight (LOS) of the SBAS satellite for which a signal has been acquired, in receiver “warm” and “hot” start modes. | 10-02-2014 |