STUDY OF CYCLE SLIPS AND SIGNAL TO NOISE RATIO IN DUAL FREQUENCY GPS RECEIVER

The applications of Global Positioning System (GPS) are increasing rapidly in every area and the requirement for precise navigation is becoming more important. The positional accuracy of GPS is affected by many factors including clock biases and atmospheric delays; of these the ionospheric delay is significant. Inversely, GPS has also become an important tool to study various parameters of the atmosphere. The ionospheric irregularities produce scintillations at the GPS receivers in both amplitude and phase that cause cycle slips and even loss of locks. The severity of the ionospheric scintillation is measured from the S4 index derived from the signal to noise ratio. Here in this paper we present the role of ionospheric irregularities in affecting the signal to noise ratio at the receiver that causes cycle slips