Development of Saudi continuous chart datum: Arabian Gulf case study

Global navigation satellite systems (GNSS) is widely utilized in marine applications for high accuracy vertical positioning. The errors introduced to charts by the present use of traditional shore-based discrete point chart datum (CD) can become a significant part of the total vertical error and deteriorates the vertical positioning accuracy estimated by GNSS technique. Therefore, a need for developing a CD in a continuous form is essential to replace the traditional CD so that it can be transformed from/to another continuous datum such as the reference ellipsoid (WGS84). The importance of the development of CD-to-WGS84 separation model is that it can be utilized by the hydrographers to develop an accurate vertical control for hydrographic surveys applications and can be utilized by the mariners to produce an accurate dynamic electronic navigation charts (ENC). In this paper, a Saudi continuous chart datum in the Arabian Gulf area is developed to provide CD-to-WGS84 separation model. It is shown that the Saudi continuous chart datum ranges from –14.96 m to –34.64 m and can be achieved with uncertainty ranges from 0.11 m to 0.16 m. The developed CD-to-WGS84 separation model in this paper can meet many maritime applications.