Comparing with EGM96 (Lemoine et al., 1998), precisions of the prime vertical and meridional components are 6" and 3", respectively.
Altimetry profiles of ascending and descending arcs can be determined by the geoid gradient or the single difference of DOV along thetrack, and then the prime vertical and meridional components of DOV can be solved by combining thetrack gradients.
Analysis of repeated observations performed by MAAS-1 on 24 stations during the years 2009-2011 indicated that precision of observed vertical deflections was around 0.20" (arcseconds) for meridian and 0.25" for prime vertical component using single "standard field observation".
Surface vertical deflection in azimuth [alpha] can be calculated from its meridian ([bar.[xi]]) and prime vertical ([bar.[eta]]) components:
It follows that the radius of curvature in the prime vertical at a given latitude 9 is given by:
In both cases, the semi-major axis and the flattening and appear in the expression for the prime vertical radius of curvature (expression (Bomford 1971) and subsequently in the expressions for latitude and height (Defence ...
Coordinate plane yoz is a
prime vertical plane at the origin of the coordinate system.
We use stars with magnitudes between 2 and 6, zenith angles from 20[degrees] to 35[degrees] and azimuths close to meridian or
prime vertical. The stars in azimuths close to the meridian serve for latitude computation, the stars in azimuths close to the
prime vertical serve for longitude computation.
Last month I discussed the
prime vertical, the line going from the west point on the horizon up across the zenith and down to the horizon's east point.