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MOVE3 Model
Manual MOVE3
Another advantage of working with an ellipsoidal model, with latitude and
longitude as coordinate unknowns, is that the map projection is neatly kept
out of the adjustment. This advantage can be clarified if we look at the
alternative, which is a map projection plane as reference surface in the
adjustment. It then becomes necessary to account for the distortion, inherent
to map projections, within the adjustment (see paragraph 3.3.1, Purposes
and Methods of Projections). Usually these distortions are too complex for
the linearised mathematical model to handle. This makes the adjustment
using a map projection plane only locally applicable for networks of limited
size, whereas the mathematical model in MOVE3 imposes no limits on the
size of the network at all.
To summarise the advantages of the ellipsoidal model in MOVE3, one could
say that:
• The ellipsoidal model is best suited for the combination of GPS and
terrestrial measurements.
• The original observations are tested, and not observation derivatives. This
allows for a clear link between the testing and the observations.
• The distortion due to the map projection is accounted for by applying map
projection formulas before the adjustment. This makes MOVE3 applicable
for networks of any size.
2.2.2. Observation Types
MOVE3 can handle the following observation types:
• directions [R];
• distances [S];
• zenith angles [Z];
• azimuths [A];
• height differences [DH];
• local coordinates [E], [N], [H];
• GPS baselines [DX];
• observed GPS coordinates [X];
• 2D geometrical relations [GR]:
• angle between 3 points [AN];
• perpendicular [PD];
• collinearity (3 points on one line) [CL];
• distance point-line [PL];
• parallel lines [PA], including mutual distance [LL];
• perpendicular lines [AL];
• chainage [CH] and offset [PL].
Directions.
In MOVE3 directions are horizontal directions given in GON (centesimal
degrees), DEG (sexagesimal degrees) or DMS (degrees, minutes, seconds).
A direction is represented by observation type R, followed by a digit
specifying the series, default R0. A maximum of 100 series per station is
allowed.
@ Grontmij Geogroep
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