Geometric Dilution of Precision (GDOP) is a coefficient for constellations of Global Positioning System (GPS) satellites. These satellites are organized geometrically. Traditionally, GPS GDOP computation is based on the inversion matrix with complicated measurement equations. A new strategy for calculation of GPS GDOP is construction of time series problem; it employs machine learning and artif...

BACKGROUND Most water access studies involve self-reported measures such as time spent or simple spatial measures such as Euclidean distance from home to source. GPS-based measures of access are often considered actual access and have shown little correlation with self-reported measures. One main obstacle to widespread use of GPS-based measurement of access to water has been technological limit...

Spatial baseline determination is a key technology for interferometric synthetic aperture radar InSAR missions. Based on the intersatellite baseline measurement using dual-frequency GPS, errors induced by InSAR spatial baseline measurement are studied in detail. The classifications and characters of errors are analyzed, and models for errors are set up. The simulations of single factor and tota...

Kalman filter (KF) uses measurement updates to correct system states error and to limit the errors in navigation solutions. However, only when the system dynamic and measurement models are correctly defined, and the noise statistics for the process are completely known, KF can optimally estimate a system’s states. Without measurement updates, Kalman filter’s prediction diverges; therefore the p...

Traditionally structural response due to severe conditions has been measured using accelerometers. However it is a relative acceleration measurement. The displacement from acceleration measurement cannot be obtained directly by simply applying the laws of motion through double integration. GPS-RTK offers direct displacement measurements for dynamic monitoring, but it has its own limitations. Th...

In this paper, the detection of a fault in the Global Positioning System (GPS) measurement is addressed. The class of faults considered is a bias in the GPS pseudorange measurements. This bias is modeled as an unknown constant. The fault could be the result of a receiver fault or signal fault such as multipath error. A bias bank is constructed based on set of possible fault hypotheses. Initiall...

Measurement and verification are one of the prime stages in the entire course of geometrical products in new generation of geometrical product specifications (GPS) standard. Like other kinds of form tolerances, flatness error is one of the important characteristics affecting the functionality and quality of machined components; sufficient efforts have long been made to determine the flatness er...

For operational use, the photo orientations of a block with more than 1000 images have been determined with an LCR88 inertial measurement unit (IMU) and GPS. The relation of the IMU to the camera and corrections for the GPS-data of the projection centers have been determined and improved by means of a small reference block with 5 – 8 photos. For checking purposes the photo coordinates of 252 ph...

Existing localization techniques such as GPS have fundamental limitations which preclude deployment in urban canyons or areas with inconsistent network availability. Augmenting GPS requires specialized infrastructure or tedious calibration tasks which limit general purpose applications. In this paper, we examine the utility of cooperatively sharing location data among connected nodes in order t...