Nowadays, navigation is an unavoidable fact in military and civil aerial transportations. The Global Positioning System (GPS) is commonly used for computing the orientation or attitude of a moving platform. The relative positions of the GPS antennas are computed using the GPS code and/or phase measurements. To achieve a precise attitude determination, Carrier phase observations of GPS requiring...

A differential global positioning system (DGPS) is one of the most widely used augmentation systems for a low-cost L1 (1575.42 MHz) single-frequency GPS receiver. The positioning accuracy of a low-cost GPS receiver decreases because of the spatial decorrelation between the reference station (RS) of the DGPS and the users. Hence, a network real-time kinematic (RTK) solution is used to reduce the...

In this paper the performance of GPS timing under jamming conditions is evaluated in the context of a GPS jammer localization system that uses the TimeDifference-Of-Arrival (TDOA) technique. To investigate the performance of GPS timing receivers under jamming conditions, jammer signals of different types and powers were combined with real GPS signals and input into two timing receivers and the ...

This article investigates the basic theory of software-based receivers for L1-band civilian GPS applications, including a discussion of signal acquisition and tracking, and the need for bit synchronization in the receiver. Also included is a brief description of an L1-band GPS receiver, the MAX2741, which serves as a compact and inexpensive RF front-end for the receiver. A similar article appea...

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 describes a new software method called “averaging correlation” to do block level GPS C/A code acquisition and tracking in frequency domain with smaller FFT blocks. The method retains the signal to noise ratio observed in more expensive correlators. Frequency domain software processing will become more feasible and popular if this method is implemented in civil GPS receivers.

The satellite-to-ground communications are influenced by ionospheric plasma which varies depending on solar and geomagnetic activities as well as regions and local times. With the expansion of use of the space, continuous monitoring of the ionospheric plasma has become an important issue. In Global Positioning System (GPS), the ionospheric delay, which is proportional to ionospheric total elect...

The standard scenario for GPS surveying is to use two carrier phase-tracking GPS receivers, one located at a "reference" station with known coordinates and the second one at a station whose coordinates are to be determined. (It is also possible to determine a trajectory when the second receiver is in motion.) However, the cost of two GPS receivers, and associated software, is high and has precl...

Integer ambiguity fixing has been recently applied to undifferenced GPS phase measurements to achieve precise positioning or PPP-AR. This technique relies on the estimation of specific phase biases combination identification and application. It works for dual-frequency GPS receivers. However, this phase biases representation is not suitable for triple frequency receivers, as the number of possi...

Reliable and precise electrical wave measurements are essential to the stability and efficiency of a power system. Phasor Measurement Units (PMUs), also known as synchrophasors, are devices that provide precise synchronized voltage magnitude and phase measurements at a high sampling frequency. Widely regarded as one of the most vital devices in monitoring and control for the future of power sys...