MeasData provides Measure computing data
Intended use:
Internal
Review Status
- Reviewed By:
- UNKNOWN
- Date Reviewed:
- before2004/08/25
- Test programs:
- tMeasMath
Prerequisite
Etymology
MeasData from Measure and Data
Synopsis
MeasData contains the constant data necessary for precession, nutation and other Measure related calculations.
Database (Table) related data, or data that can be changed by the user, is available in the MeasTable class.
All data. apart from a set of simple constants:
static const Double JDCEN
Length Julian century.
static const Double MJDB1900
MJD of B1900.0.
static const Double TROPCEN
Length Tropical century.
static const Double MJD2000
General constants.
static const Double MJDB1950
MJD of B1950.0.
static const Double SECinDAY
Length of day in sec.
static const Double MJDB1850
MJD of B1850.0.
are obtained by calls to a method. This class contains no constructors or destructors, only static methods and (static) constants.
References:
Explanatory supplements to the Astronomical Almanac
C. Ron and J. Vondrak, Bull. Astron. Inst. Czechosl. 37, p96, 1986
M. Soma, Th. Hirayama and H. Kinoshita, Celest. Mech. 41, p389, 1988
V.S. Gubanov, Astron. Zh. 49, p1112, 1972 (English translation: Sov. Astronomy - AJ, Vol. 16, No. 5, p. 907)
Example
Usage examples can be found in Precession
Motivation
To create a clean interface between the actual calculations and the methods to obtain the parameters for these calculations. Note that the tables are in general in the format and units found in the literature. This is to be able to easy check and change them. However, in the future re-arrangement could produce faster and more compact code.
To Do
-
more precise data for VLBI and pulsar
Definition at line 99 of file MeasData.h.