Contents

## **Preface XI**


**Section 2 GPS Technology Applications 21**

and C. Venkatramanan


#### **X** Contents


Preface

ties, and many others.

and collection of required data.

Global Positioning System (GPS) is a satellite constellation expanded for the use of naviga‐ tion, positioning of the objects on Earth or outer space, and timing. There is a wide range of applications of the use of GPS within the above framework, e.g., land surveying, cartogra‐ phy/geodesy/mapping, land transportation, telecommunications, scientific research activi‐

This book addresses the general aspects of GPS applications with a reflection of the funda‐ mental bases of the technology structure, segments, and elements. It has been demonstrated that satellite systems use orbits for this purpose, and the facilities of receivers for gathering

There is no doubt that it is always challenging to provide detailed classification of informa‐ tion using advanced methods and technologies to embrace expectations in processing. In this book the use of computer neural networks with the integration of GPS data is demon‐ strated for ionosphere modeling. This has been performed by applying GPS technology to

An assessment of GPS Total Electron Content (TEC) covers the spatial equatorial ionization anomaly (EIA) region with two solar cycles. It reflects ionosphere variability in space, time, and geographical location. It has been presented by different phases of the solar cycle, EIA, and annual, daily, diurnal, and seasonal variability of the ionosphere in the Northern Hemi‐ sphere. This book demonstrates comprehensive research into high and random variability of TEC associated with the changes in solar activity, intensity of the sun's radiation, zenith an‐ gle at which they impinge Earth's atmosphere, equatorial electrojet, and plasma flow.

One more aspect of GPS is the successful selection and application of appropriate software utilization. This depends on what kind of task and data need to be solved and collected for expected outcomes within conducted measurements. It is a vital option and a subject of GPS

The book estimates the error originating at the receiver due to multiple paths taken by the satellite transmitted radiofrequency (RF) signal. It is a very important subject in urban areas, and is the major error among other GPS error sources taking place at the receiver. It has been calculated as a multipath error using code range, carrier phase range, and carrier frequencies. The proposed algorithm considers the random nature of the multipath error and avoids com‐ plex calculations involved in the error calculations. Based on such an approach a valuable aid in precise navigation, surveying, and ground-based geodetic studies has been achieved.

This book also presents review materials dedicated to the Global Navigation Satellite Sys‐ tem (GNSS) with a description of its structure control, space, and use elements. In the mean‐

study the ionosphere based on the development of artificial neural networks.

technology, which has been studied and undertaken in this book.

Chapter 9 **Ionosphere Variability in Low and Mid-Latitudes of India Using GPS-TEC Estimates from 2002 to 2016 185** Sridevi Jade and Shrungeshwara T.S.
