Astronomical Applications Department, U.S. Naval Observatory NAO 150 Page 18
I. Transverse
(position)
A. Optical
observations
1. Global
positions
a. Transit
circle
2. Differential
positions
II. Radial
(timing)
A. Doppler
observations
1. Oneway
a. Pulsars
b. Spacecraft
2. Twoway
a. Radar
b. Spacecraft
B. Time delay observations
1. LLR
2. Radar
a. Differential
radar
3. Spacecraft
a. Single
Figure 11 intentionally shows only the major class types, in accord with
the introductory nature appropriate to this Chapter. It is a simple matter to
derive further specialized classes from the base classes shown. For exam-
ple, one would derive a
VikingOrbiter
from
OrbiterPlatform
.
2.7.2. Observation Types
As previously mentioned, the various observation data types fall natu-
rally into the two broad categories: timing and position. For reasons hav-
ing mainly to do with datasets that are currently insufficiently large or in-
sufficiently accurate to have a substantial effect on ephemeris accuracy,
early versions of Newcomb will not include some of the observation
types.
Newcomb will include the following subset types
:
MURISON: MODELING PLANETARY MOTIONS
18 of 20
Figure 12 -- Observational class hierarchy.
ObservationGroup
(virtual)
TransverseObs
RadialObs
multiple inheritance
OffsetObs
TransitCircleObs
SatSatObs
SatPlanetObs
DopplerObs
SpacecraftObs
RadarObs
TimeDelayObs
OneWayDoppler
TwoWayDoppler
PulsarObs
RangeRadarObs
LLRObs
DiffRadarObs
DopplerRadarObs
OneWayDopplerSCObs
TwoWayDopplerSCObs
RangeSCObs
