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Tropospheric Delay Modeling using GNSS Observations from Continuously Operating Reference Stations (CORS)

alojaiman, shahad N M A A
http://rave.ohiolink.edu/etdc/view?acc_num=osu1574536144031026

Abstract Details

2019, Master of Science, Ohio State University, Civil Engineering.
PPP exhibits through many previous studies the possibility to achieve high accuracy estimation of tropospheric paraments. Either Zenith wet delay (ZWD) or Precipitable Water Vapor (PWV) can be estimated by PPP processing of GNSS data in either real time or post processing mode. PWV is further utilized as a tool from which rainfall forecasting models are established especially in sites where such data may not be available. In this study PPP processing of GNSS data leads to the estimation of ZTD as well as ZWD values. A test is first conducted in which MGEX sites are processed on July 22nd, 2019 and January 11th, 2019 to estimate ZTD values and establish PPP’s accuracy based on IGS final solutions and tropospheric products as reference data. An approach in which the site coordinates are fixed instead of estimated by PPP is then tested on the same MGEX sites to examine its contribution to the accuracy of ZTD estimates. 37 CORS sites around the United States are then processed for three day between August 7th 2019 and August 9th 2019 with PPP and site coordinates fixing to create ZTD, ZWD, and PWV maps of the area from which patterns and models can be generated. The created maps were analyzed alongside NASA’s Goddard Earth Sciences Data and Information Services Center’s precipitation maps of near real time and TRMM Multi-Satellite Precipitation Analysis TMPA products. Finally, PWV reference data was obtained from UCAR’s COSMIC program and daily averaged to be compared with the PWV values extracted from the previously estimated ZWD. The PPP processing of MGEX sites with GPS and GLONASS data resulted in mm level differences between estimated and referenced ZTD data with RMS values as low as 1.55 mm. Site coordinates fixing enhanced ZTD estimates slightly based on the same referenced ZTD data. The examination of maps showed clear consistency between the estimated ZWD as well as PWV maps of the area and the reference precipitation maps of the same day especially as precipitation and weather patterns changed daily. The estimated PWV maps reflected that change from day to day specifically the prominent changes observed around the NESC, NEST, and DSRC sites. PWV validation resulted in PWV errors mostly less than 2 mm and as low as 0.18 mm. The approach has the potential of further CORS network expansion for a more accurate model with location correlated parameters to estimates PWV considered. Future work could also include real time PPP processing with ambiguity fixing to enhance ZWD estimation.
Lei Wang, Ph.D (Advisor)
Rongjun Qin, Ph.D (Committee Member)
Yilmaz Alper, Ph.D (Committee Member)
140 p.
Civil Engineering
PPP; CORS; Tropospheric delay; Continuously Operating Reference Stations; GNSS; IGS; GPS; MGEX; Zenith total delay; Zenith wet delay; PWV; ZTD; ZWD; Precipitable Water Vapor

Recommended Citations

Citations

  • alojaiman, S. N. M. A. A. (2019). Tropospheric Delay Modeling using GNSS Observations from Continuously Operating Reference Stations (CORS) [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574536144031026

    APA Style (7th edition)

  • alojaiman, shahad. Tropospheric Delay Modeling using GNSS Observations from Continuously Operating Reference Stations (CORS). 2019. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1574536144031026.

    MLA Style (8th edition)

  • alojaiman, shahad. "Tropospheric Delay Modeling using GNSS Observations from Continuously Operating Reference Stations (CORS)." Master's thesis, Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574536144031026

    Chicago Manual of Style (17th edition)

osu1574536144031026
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This open access ETD is published by The Ohio State University and OhioLINK.