Eclipses

KRC differentiates daily eclipses, such as those experiences by Galilean satellites, from rare eclipses, for example partial solar eclipse by Phobos as seen from the surface of Mars.

Daily Eclipses

Daily eclipses are recurring events modeled identically for each day of the year. To include a daily, eclipse, a few parameters must be specified:

Eclipse #forces an eclipse (Default = "F")

Eclipser #Eclipser name, for example "Mars_Mars" for a Phobos or Deimos study

Ecl_Cent_Hr #Eclipse central hour [0-24]

Bias #Eclipse Bias (0 => perfect alignement; 1 => partial eclipse); see below for a graphical definition of Bias

Eclipse_Style = 1 #=1 Forces daily eclipses

Date #[ J2000 date of Rare eclipse ] Unused by the KRC for rare eclipses (but required / need to test?)

Example: include a solar eclipse by Mars on Phobos using standard Phobos/Mars orbital properties:

Eclipse = "T" #forces an eclipse (Default = "F")

Eclipser = "Mars_Mars" #Eclipser name

Ecl_Cent_Hr = 12. #Eclipse central hour

Bias = 0.0 #Eclipse Bias (0 => perfect alignement; 1 => partial eclipse)

Eclipse_Style = 1

Date = 0.

out = krc( lat = 12. ,INERTIA = 50. ,body = "Mars,Phobos", LKofT = "T", Eclipse = Eclipse, Eclipser = Eclipser, Ecl_Cent_Hr = Ecl_Cent_Hr, Bias = Bias, Eclipse_Style = Eclipse_Style,Date = Date)

When working with eclipses, it may be beneficial to increase the time resolution of the output by increasing N24

out = krc( lat = 12. ,INERTIA = 50. ,body = "Mars,Phobos", LKofT = "T", Eclipse = Eclipse, Eclipser = Eclipser, Ecl_Cent_Hr = Ecl_Cent_Hr, Bias = Bias, Eclipse_Style = Eclipse_Style,Date = Date, N24 = 96 * 100)

Rare Eclipses

Rare eclipses are one time events. To include a rare, eclipse, a few parameters must be specified:

Eclipse #forces an eclipse (Default = "F")

Eclipser #Eclipser name, for example "Mars,Phobos" for a partial solar eclipse by Phobos

Ecl_Cent_Hr #Eclipse central hour [0-24]

Bias #Eclipse Bias (0 => perfect alignement; 1 => partial eclipse); see below for a graphical definition of Bias

Eclipse_Style = 2 #=2 Forces rare eclipses

Date #[ J2000 date of Rare eclipse ]

DEVELOP AN EXAMPLE HERE

SEE IF fort46 file is being written

Definition of Bias

Eclipses require to provide the "Bias", defined as Sun/Eclipsed Body center line closest approach to the Occulting Body center, as a fraction of the Occulting Body radius; + is North.

See the figure below: the Bias quantifies how "long" or how "perfect" an eclipse is, and is quantified for Earth as "Gamma" (here Bias = -0.3014).

Input Files

Earth/Moon

MoonA.inp

Mars/Phobos

PhoH.inp

Europa/Jupiter

EurH.inp

Known Issues

1. If Ecl_Cent_Hr is provided, an eclipse will be simulated even if Eclipse is set to "F"