Analysis of GPS TEC observations using singular value decomposition model over low latitude regions | |
| Author | Raghavendra, Neeli Rayappa |
| Call Number | AIT Thesis no.RS-17-11 |
| Subject(s) | Geographic information system Decomposition method |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Remote Sensing and Geographic Information Systems |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. RS-17-11 |
| Abstract | The satellite based radio communication and navigation systems are vulnerable to the variable dynamics of low latitude ionosphere. Interplanetary space weather phenomenon acts as a crucial factor for the formation of the non-linear temporal and spatial differences in the time series of total electron content (TEC) values. Therefore, a method is essential to model the ionospheric TEC variations for a reliable GNSS positioning performance. In this paper, a Singular Value Decomposition (SVD) model is implemented in order to recognize the TEC time series of daily, temporal as well as seasonal characteristics during the solar maximum period (2015) in the 24thsolar cycle. The Vertical Total Electron Content (VTEC) analysis has-been carried out with GNSS data sets collected from Asian Institute Of Technology Bangkok AITB, Thailand (14.07° N, 100.61° E), Guntur, India (16.44° N, 80.62° E), and Bengaluru, India (12.97° N, 77.59°E) stations located in low-latitude region. The first three singular value modes constitute about 98% of the total variance of the observed TEC data sets. The Fourier Series Analysis (FSA) is carried out to characterize the solar-cycle, annual and semi-annual dependences through modulating the first three singular values by the solar (F10.7) and geomagnetic (Ap) indices. A positive correlation (0.75) of daily averaged GPS-TEC with daily averaged F10.7 strongly supports the time-varying characteristics of the ionosphere features depends on the solar activity. Further, the validity and reliability of SVD model is evaluated by comparing with the GPS-TEC data, and standard global models (International Reference Ionosphere, IRI2016 and Standard Plasma-sphere Ionosphere Model, SPIM). From the results, it is evident that the SVD model demonstrates better linear correlation and high accuracy than the standard global models. SVD-TEC model would be a useful tool for monitoring and detecting the ionospheric variations |
| Year | 2017 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. RS-17-11 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Remote Sensing (RS) |
| Chairperson(s) | Tripathi, Nitin Kumar |
| Examination Committee(s) | Sarawut Ninsawat;Raju, Durairaju Kumaran;Ratnam, Venkata |
| Scholarship Donor(s) | AIT Fellowship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2017 |