GPS and low-cost INS integrated system are expected to become more widespread as a result of the availability of low cost inertial Micro-Electro-Mechanical Sensors (MEMS). Currently most of the integration systems are based on the differential GPS (DGPS) to ensure the navigation performance. However with the requirements of the base station, the system cost and complexity are significantly incr...

A new method of sensing the vibrational motions of a exible structure by measuring the di erence in GPS (global positioning system) carrier phase at separate antennas on the structure is presented. Differential carrier phase measurements have been recently used to determine the attitude of rigid bodies such as aircraft and spacecraft, and for aircraft landing with ground based GPS pseudolites. ...

The announcement by U.S. President Bill Clinton to turn off 'Selective Availability' at midnight (Washington DC time) 1 May 2000 caught everyone by surprise. This decision to stop degrading the accuracy of the Global Positioning System's (GPS) Standard Positioning Service (SPS) will have a significant impact on users all over the world. One important outcome for the geomatics community is that ...

This paper examines the performance of several precise point positioning (PPP) models, which combine dual-frequency GPS/Galileo observations in the un-differenced and between-satellite single-difference (BSSD) modes. These include the traditional un-differenced model, the decoupled clock model, the semi-decoupled clock model, and the between-satellite single-difference model. We take advantage ...

This paper presents a tightly-coupled integration of GPS observations and ultra-wideband ranges that accounts for systematic UWB errors in real-time using additional error states to augment an extended Kalman filter. Results of range measurements obtained using commercially available UWB radios in optimal line-of-sight conditions are compared to surveyed ranges using conventional methods to ass...

This study aimed to determine the validity and reliability of a 5 Hz GPS system for recording distance and velocity during non-linear cycling activity. One trained male cyclist (age 37 yrs; stature 172.4 cm; body mass 74.2 kg) took part in the study. Two non-differential GPS units (Minimax X3, Catapult) were attached securely into the rear pocket of a cycling shirt at approximately the T11-12 v...

Radio frequency interference (RFI) is one of the foremost concerns in safety critical applications that utilize GPS. RFI sources either intentional or unintentional at the vicinity of the victim receiver can potentially mask the weak GPS signals. Most commercial receivers are equipped with no or basic level of protection against in-band RFI. Acquisition under strong RFI is more difficult as the...

Error is always present in the GPS guidance of a tractor along a desired trajectory. One way to reduce GPS guidance error is by improving the tractor positioning. The most commonly used ways to do this are either by employing more precise GPS receivers and differential corrections or by employing GPS together with some other local positioning systems such as electronic compasses or Inertial Nav...

GPS instrumentation capable of measuring a missile intercept event with less than 2-centimeter accuracy has been demonstrated in a special high speed/acceleration sled test at Holloman AFB. Although the basic instrumentation technique is well defined, plans to properly exploit this capability are yet to be adequately addressed. This paper reviews the demonstrated differential GPS instrumentatio...

in this paper a practical method for tropospheric effects on gps derived coordinates in absolute mode is presented. gps observations at the permanent gps stations can be used as source of information for the modeling. the developed model is a time-dependent model and as such differs from usual tropospheric models, which are based on atmospheric parameters, i.e. temperature, pressure and humidit...