Vertical Offshore Reference Frames

Thus VORF directly permits the use of high precision GNSS in hydrographic survey, and also allows the capability of transforming vertical data between the different datums.

[1] The UK Maritime & Coastguard Agency requires the use of VORF for tidal reductions as part of its civil hydrography programme.

[3] A main product of the VORF project was the gridded vertical correction files which deliver the capability to transfer heights and depths from one vertical reference system to another, "allowing the direct use of depth data from surveys which is referred to a WGS84 compatible datum rather than Chart Datum and thus enabling Hydrographic surveyors to survey without the need to measure tides".

[5] There is higher resolution in estuaries and inlets, but for most of the areas covered, there is a single height correction for each roughly 900 by 500 metre rectangle.

The filename indicates the VORF model version, the south-west corner of the area covered, and the pair of datums it represents.