Penentuan Zenith Tropospheric Delay Dan Precipitable Water Vapor Menggunakan Perangkat Lunak Gamit

The signals from each Global Positioning System (GPS) satellites that orbiting above the earth\u27s surface will be received by a receiver through the layers of atmosphere. The signal that in electromagnetic waves form will experience the biggest obstacle in ionosphere and troposphere. The amount of deviation due to a slowdown in signal\u27s travel time as it passes through the troposphere called tropospheric delay. This measurement can also be extracted into precipitable water vapour by using the surface meteorological data. This study was conducted to determine the zenith tropospheric delay and precipitable water vapour using scientific software GAMIT starts from doy 090 to 096 in 2014. By utilizing 10 GPS CORS observation points owned by Badan Informasi Geospasial in Bantul, Cilacap, Kebumen, Magelang, Purbalingga, Pekalongan, Purwodadi, Semarang, Solo, and Tegal. It also connected to 4 area points of IGS, that are: ALIC, COCO, NTUS, and PIMO Station. This research produces the value of temporal variation in zenith tropospheric delay observation point ranges between 2446.2 - 2754.5 mm and the value of temporal variation of precipitable water vapor ranges between 38.81 - 64.46 mm. The validation results between the ZPD data in IGS Station and the ZTD that was processed by GAMIT is 5.599 mm of RMS error average with a 97.73% of correlation for the spza project, 5.425 mm with a 97.86% of correlation for the spzb project, and 10.462 mm with a 92.99% of correlation for the spzc project