Action #1855

Add GSkyDir::moon() method

Added by Knödlseder Jürgen about 8 years ago. Updated about 5 years ago.

Status:ClosedStart date:09/28/2016
Priority:NormalDue date:
Assigned To:Knödlseder Jürgen% Done:

100%

Category:-
Target version:1.7.0
Duration:

Description

A moon(const GTime& time) method should be added to the GSkyDir class that returns the position of the moon for a given time with an accuracy sufficient for gamma-ray astronomy (see #1854 for a corresponding method for the Sun position).

Moon_position_difference.png (110 KB) Knödlseder Jürgen, 11/14/2019 12:05 AM

test_moon_ephem.py Magnifier (3.55 KB) Knödlseder Jürgen, 11/14/2019 12:05 AM

Moon_position_difference

Recurrence

No recurrence.

History

#1 Updated by Knödlseder Jürgen over 5 years ago

  • Target version set to 1.7.0

#2 Updated by Knödlseder Jürgen about 5 years ago

The method has been implemented inspired by the IDL code moonpos.pro, see https://github.com/awmann/amObserve/blob/master/moonpos.pro. A note on the computation method can be found at https://ntomasse.web.cern.ch/Notes/tomassetti_ams02algorithms.pdf.

I used the script test_moon_ephem.py to compare the Moon position computed using GSkyDir::moon() to the one computed using PyEphem, the results are shown below for the period 2000 - 2050. Overall the accuracy is quite good, but becomes worse at the end of the period. However, it never becomes worse than 1 arcmin, which should be okay for gamma-ray astronomy.

#3 Updated by Knödlseder Jürgen about 5 years ago

  • Status changed from Pull request to Closed

Merged into devel.

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