Remote sensing
Fereydon Nobakht Orsi; Abdolreza Safari; Amir Khodabandeh
Volume 14, Issue 3 , September 2021, , Pages 101-108
Abstract
In this paper, we discussed standard point positioning technique based on the single frequency code-based (C/A) receivers. Then, we presented its performance by means of different measures. However, the use of one single frequency GPS receiver to obtain high-precision positioning make a major challenge ...
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In this paper, we discussed standard point positioning technique based on the single frequency code-based (C/A) receivers. Then, we presented its performance by means of different measures. However, the use of one single frequency GPS receiver to obtain high-precision positioning make a major challenge due to the environmental biases, in particular the ionospheric effects are handled. The main objective of the present study is to integrate a inospheric model such as Klobuchar Inospheric Model (KIM) with imprecise code (C/A) observations under intense geomagnetic storm conditions, then, to obtain dm level positioning accuracy using Kalman filter. For this purpose we used code (C/A) observations on two different days (February 26, 2018 and December 20, 2015) at Tehran station. The results show that we could obtain multi-dm level positioning accuracy under geomagnetic storm condition by using Kalman filter that will be important in the field of kinematic applications.
F. Nobakht-Orsi; M. A. Sharifi; A. R. Safari
Volume 4, Issue 1 , July 2011, , Pages 15-22
Abstract
In this paper, Hilbert Huang transform (HHT) for time series analysis of the status of permanent GPS stations can be provided. Hilbert Huang transform and its, related spectrun is a new method for the analysis of nonlinear processes.This method represents not only a precision analysis in the time-frequency ...
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In this paper, Hilbert Huang transform (HHT) for time series analysis of the status of permanent GPS stations can be provided. Hilbert Huang transform and its, related spectrun is a new method for the analysis of nonlinear processes.This method represents not only a precision analysis in the time-frequency space, but also it declares the physics of the dynamic processes. This method has two speps. At the first step, the data is disintegrated into IMF elements by EMD method. At the second step Hilbert transform is applied for IMF elements and distribution of the time-frequency –Hilbert energy spectrum is then determined. In this spectrum, Location, frequency and energy defined by time events for the Hillbert transform will be reserved. So instantaneous frequency will have a major role in this method.
