NIMA OBSERVATION FILE FORMAT
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The observation file for each object has the following format and meaning:

1.  type: O is for classic observation, otherwise it is 'S' for space observation or 'G' for Gaia observations
2.  year of the observation
3.  month of the observation
4.  decimal day of the observation in UTC
5.  RA (deg)
6.  DEC (deg)
7.  IAU observatory code
8.  bias correction in RA (arcsec) according to Farnocchia et al. 2015 in the sense new RA= RA - bias_alpha/cos(DEC)
9.  bias correction in DEC (arcsec) according to Farnocchia et al. 2015 in the sense new DEC= DEC - bias_delta
10. weight in R.A. (arcsec) or more precisely it is the estimated precision and weight is 1/(precision^2)
11. weight in DEC (arcsec)
12. flag (1 indicates the position is used for the fit, 0 otherwise)
13. stellar catalogue used for reduction (MPC code : https://minorplanetcenter.net//iau/info/CatalogueCodes.html)
14. source of data : A is for MPC, O is for observations from our group (not in MPC), o is for occultation, M is our observations but in MPC format (less precise), P is for old version of our observations (before 2013-14), F is for Fraser and al. 2013?
15. number of observations in the set (ie. same night and same observatory)
16. random number associated to the set
17. O-C in RA x cos(delta) in arcsec
18. O-C in DEC in arcsec
19. xhi  of the observation: xhi^2= O-C_alpha^2/weight_alpha^2 + O-C_delta^2/weight_delta^2. Usually, the observation is rejected when xhi>3 or 4

Note that when type is 'S' or 'G' there is a second line with basically the position of the spacecraft.

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Author: J.Desmars
Date: 2020.10.25
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