Establishment of new continuous operating reference station (CORS) at faculty of engineering, ain shams university

Abstract

In this work, establishment and operation of new Continuous Operating Reference Station (CORS), at Faculty of Engineering, Ain Shams University, Cairo, Egypt, will be discussed. In addition, tying this station to the Egyptian CORS network will be performed using 3 different positioning techniques. The first technique is the Precise Point Positioning (PPP), while the second is the Differential Global Navigation Satellite System (DGNSS) technique with respect to the International GNSS Service (IGS) stations. The third technique is the DGNSS positioning with respect to stations of the Egyptian CORS network. Solutions of the third technique will be used as reference coordinates to assess the quality of using the PPP or the IGS DGNSS techniques in tying new stations, observed at the present time, to the Egyptian CORS network. Both techniques will be assessed using GNSS data for 4 days in month June 2017. In addition, 24 hours observation periods and 4 hour observation periods (day hours and night hours) will be evaluated. GNSS data, for the same 4 days, for a number of stations of the Egyptian CORS network were obtained from the Egyptian Survey Authority (ESA) to be used in the third technique to derive reference coordinates in the assessment process. This study shows that the IGS DGNSS solutions achieved much better results than the PPP solutions. The IGS DGNSS solutions could get coordinates with mean horizontal positional difference 2.5cm in case of using 24 hours observation periods, 3.5cm in case of using 4 hours (day hours) observation periods and 2.8cm in case of using 4 hours (night hours) observation periods. Generally, using the IGS DGNSS positioning technique in tying new stations to the Egyptian CORS network can achieve very promising results and help to avoid many administrative restrictions and additional costs. Also, the 4 hours observation periods can achieve promising results which make it applicable to the different surveying works performed in Egypt.