Module functions

Mars24 algorithm

Mars Calendar and orbit calculation based on Allison and McEwan (2000), Allison (1997)

Allison, M., and M. McEwen 2000. A post-Pathfinder evaluation of aerocentric solar coordinates with improved timing recipes for Mars seasonal/diurnal climate studies. Planet. Space Sci. 48, 215-235

Allison, M. 1997. Accurate analytic representations of solar time and seasons on Mars with applications to the Pathfinder/Surveyor missions. Geophys. Res. Lett. 24, 1967-1970.

http://www.giss.nasa.gov/tools/mars24/

marstime.Clancy_Year(j2000_ott=None)

Returns the Mars Year date based on the reference date from Clancy(2000): 1955 April 11, 11am

marstime.Coordinated_Mars_Time(j2000_ott=None)

The Mean Solar Time at the Prime Meridian

marstime.FMS_Angle(j2000_ott=None)

Returns the Fictional Mean Sun angle

marstime.Local_Mean_Solar_Time(longitude=0, j2000_ott=None)

The Local Mean Solar Time given a planetographic longitude

marstime.Local_True_Solar_Time(longitude=0, j2000_ott=None)

Local true solar time is the Mean solar time + equation of time perturbation

marstime.Mars_Ls(j2000_ott=None)

Returns the Areocentric solar longitude (aka Ls)

marstime.Mars_Mean_Anomaly(j2000_ott=None)

Calculates the Mars Mean Anomaly given a j2000 julian day offset

marstime.Mars_Solar_Date(j2000_ott=None)

Return the Mars Solar date

marstime.Mars_Year(j2000_ott=None, return_length=False)

Returns the Mars Year date based on the reference date 1955 April 11, 10:56:31 mtc after finding the j2k offsets of the zeroes of the Mars_Ls function.

marstime.alpha_perturbs(j2000_ott=None)

Returns the perturbations to apply to the FMS Angle from orbital perturbations

marstime.east_to_west(east)

Interface, calls west_to_east to convert longitude

marstime.equation_of_center(j2000_ott=None)

The true anomaly (v) - the Mean anomaly (M)

marstime.equation_of_time(j2000_ott=None)

Equation of Time, to convert between Local Mean Solar Time and Local True Solar Time, and make pretty analemma plots

marstime.heliocentric_distance(j2000_ott=None)

Instantaneous orbital radius

marstime.heliocentric_latitude(j2000_ott=None)

Heliocentric Latitude, which is not Ls

marstime.heliocentric_longitude(j2000_ott=None)

Heliocentric longitude, which is not Ls (offsets are different)

marstime.hourangle(longitude=0, j2000_ott=None)

Hourangle is the longitude - subsolar longitude

marstime.j2000_epoch()

Returns the j2000 epoch as a float

marstime.j2000_from_Mars_Solar_Date(msd=0)

Returns j2000 based on MSD

marstime.j2000_offset_tt(jday_tt=None)

Returns the julian day offset since the J2000 epoch

marstime.j2000_ott_from_Mars_Solar_Date(msd=0)

Returns j2000 offset based on MSD

marstime.julian(m=None)

Returns the julian day number given milliseconds since Jan 1 1970

marstime.julian_tt(jday_utc=None)

Returns the TT Julian day given a UTC Julian day

marstime.mills()

Returns the current time in milliseconds since Jan 1 1970

marstime.solar_azimuth(longitude=0, latitude=0, j2000_ott=None)

Azimuth Angle, between sun and north pole

marstime.solar_declination(ls=None)

Returns the solar declination

marstime.solar_elevation(longitude=0, latitude=0, j2000_ott=None)

Elevation = 90-Zenith, angle between sun and flat surface

marstime.solar_zenith(longitude=0, latitude=0, j2000_ott=None)

Zenith Angle, angle between sun and nadir

marstime.subsolar_longitude(j2000_ott=None)

returns the longitude of the subsolar point for a given julian day.

marstime.utc_to_tt_offset(jday=None)

Returns the offset in seconds from a julian date in Terrestrial Time (TT) to a Julian day in Coordinated Universal Time (UTC)

marstime.utc_to_tt_offset_math(jday=None)

Returns the offset in seconds from a julian date in Terrestrial Time (TT) to a Julian day in Coordinated Universal Time (UTC) [MATH]

marstime.utc_to_tt_offset_numpy(jday=None)

Returns the offset in seconds from a julian date in Terrestrial Time (TT) to a Julian day in Coordinated Universal Time (UTC) [NUMPY]

marstime.west_to_east(west)

Convert from west longitude to east longitude, or vice versa.