Geoid Heights and Geodetic Positions of Pacific Harbors and Deep Sea Drilling Sites.
Abstract
A relatively simple double pass method is used to (A) reduce longitudinal spread of satellite navigation fixes and (b) obtain antenna height or sea level height on board a ship in a fixed harbor or fixed open-sea position (over an acoustic beacon). Required are the satellite navigator output or latitude, longitude, elevation angle, and path geometry for two consecutive passes (one east and one west of the site) of the same satellite. The standard deviation of one such double pass observation in a larger data set is usually below 20 m in both longitude and height. Improvements in the position accuracy of a site (as measured by sigma sub m, the standard deviation of the mean or the 95% confidence interval) are obtained by restricting observations to passes: with a high number of symmetric Doppler counts, between given elevation angles, with a small number of iterations of the satellite navigator, and with eliminations of double pass results that are outside specified limits (usually 2 sigma sub m) in height and/or longitude. An accuracy sigma sub m, of 10 m or less is usually achieved with four to five days of recordings.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1976
- Accession Number
- ADA034869
Entities
People
- Eduard Berg