Fast Determination of the Vertical Deflection and Its Precision Analysis of Any Point on the Land and Sea in China

This paper states the methods for establishing a 1'×1' digital model of the vertical deflection and presents the data . The results of precision estimation in both the prime vertical component and the meridian component for this model achieved through adapting the 1 489 high\|accuracy astro\|geodetic points as check points are: ±0.94″ and ±0.99″ for the eastern region, respectively, ±1.71″ and ±1.28″ for the northwest region, respectively, ±1.95″ and ±2.00″ for the southwest region and the general precision for the whole country is better than ±1.5″. Generally, the determination of the vertical deflection on any point using the model and its corresponding software can be realized within 2 seconds.