Orthometric Height Determination Through MyRTKnet Virtual Reference Station Mohd Zainee Zainal  , Kamaluddin Hj Talib  & Azhari Mohamed   Faculty of Architecture, Planning and Surveying University Teknologi MARA (UiTM) Malaysia, 40450 Shah Alam, Selangor, Malaysia  Jabatan Ukur dan Pemetaan Malaysia, Wisma JUPEM, Jalan Semarak, 50578, Kuala Lumpur KEY WORDS: GPS, VRS, RTK, MyRTKnet, GSM, GPS Heighting Abstract: Height is usually determined by using levelling method. The equipment used for this purpose is an automatic level and a vertical staf. At least 2 personnel needed to do this kind of job. For a small scale job, 2 personnel are already sufficient. But for a large scale job, it may require more man power and very time consuming. Regarding to that, it also will affect the cost for the project. While GPS can give a 3 dimensional position for a point, it can be used as equipment for height determination. The cost of the project can be reduced, less man- power needed and also it may reduce the time for the job to finish. In this study, the RTK VRS is used to determine the height of the selected points. Malaysia RTK Network (MyRTKnet) service is one of the systems that provide RTK VRS. It’s developed by the Department of Surveying and Mapping Malaysia (JUPEM). For this study, the RTK VRS observation is done on top of selected established Standard Benchmark (SBM). The SBM will be the reference of the true value in this study since it’s established very accurately and most likely undisturbed by any development. The result of observed value is being compared with the SBM value in order to know the difference of the height that been determined. In