Module mwa_rust_core::constants
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Useful constants.
Constants
cotter’s MWA altitude in metres. Use MWA_HEIGHT_M unless you know what you’re doing.
cotter’s MWA latitude on Earth in radians. Use MWA_LAT_RAD unless you know what you’re doing.
cotter’s MWA longitude on Earth in radians. Use MWA_LONG_RAD unless you know what you’re doing.
Seconds per day (86400)
Hour angle to radians (15 / 180 * PI).
Seconds of time to radians (7.272205216643039903848712e-5).
This is the number of seconds from 1900 Jan 1 and 1980 Jan 5. The GPS epoch
is 1980 Jan 5, but hifitime
uses 1900 for everything; subtracting this
number from the result of hifitime::Epoch::as_gpst_seconds
gives the
expected GPS time.
The number of seconds between 1858-11-17T00:00:00 (MJD epoch, used by
casacore) and 1900-01-01T00:00:00 (TAI epoch) is 1297728000. I’m using the
TAI epoch because that’s well supported by hifitime
, and hifitime
converts an epoch to many formats including JD, and accounts for leap
seconds.
MWA height (a.k.a. altitude) [metres]
MWA latitude [degrees]
MWA latitude [radians]
MWA latitude [degrees]
MWA longitude [radians]
Ratio of a solar day to a sidereal day (24/23.9344696 = 1.002737909).
Speed of light [metres/second]