In this paper we present a direct Kalman filtering approach for GPS/INS integration. In the approach, GPS and INS non–linearities are preprocessed prior to a Kalman filter. The GPS preprocessed data are taken as measurement input, while the INS preprocessed data are taken as an additional information to the Kalman filter’s state prediction. The advantage of this approach is that a simple and li...

Having combined the advantages of ground-based interferometric radar and Global Position System (GPS), a microwave radar with transponder for three-dimensional displacement monitoring method has been proposed. In this system, the active reflector ensures the long measurement distance at low antenna radiation power; the transponder provides the total solutions to antenna microwave leakage and mu...

It has been considered a fact that GPS performs too poorly inside buildings to provide usable indoor positioning. We demo raw measurements and results from a measurement campaign which show that using state-of-the-art receivers GPS availability is good in many buildings with standard material walls and roofs: The root mean squared accuracy of the measured positions is below five meters in woode...

Precise orbit determination (POD) of low earth orbiters (LEOs) with GPS is becoming a standard practice in the space science community. The need for such information has been growing rapidly due to such scientific applications as radio occultation and ever increasing demands from engineering applications such as spacebased earth sensor positioning. The conventional GPSbased POD strategies rely ...

Reliability of a navigation system is one of great importance for navigation purposes. Therefore, an integrity monitoring system is an inseparable part of aviation navigation system. Failures or faults due to malfunctions in the systems should be detected and repaired to keep the integrity of the system intact. According to the characteristic of GPS (Global Positioning System) receiver noise di...

Precise real-time information about the position and orientation of robotic platforms as well as locally consistent point-clouds are essential for control, navigation, and obstacle avoidance. For years, GPS has been the central source of navigational information in airborne applications, yet as we aim for robotic operations close to the terrain and urban environments, alternatives to GPS need t...

Both physical and social environmental factors influence young children's physical activity, yet little is known about where Hispanic children are more likely to be active. We assessed the feasibility of simultaneously measuring, then processing objective measures of location and physical activity among Hispanic preschool children. Preschool-aged Hispanic children (n = 15) simultaneously wore Q...