Update : 2023 May 25

Neocomet

1. Summary

Neocomet allows to generate scripts for ACP, PRISM and AudeLA to automatize observation of visible comets and NEOs from your observatory.

Objects selection and observation order may be setup using one of the 4 available algorithms :

Exposures length and number can be forced by the user or automatically computed according to object move, magnitude and astrometry requirement

Install AudeLA
Launch AudeLA
Add your observatory using Setup/Observer Location menu
Put uncompressed Neocomet directory <Neocomet> into the AudeLA Scripts folder or adapt this latter (Setup/Folders)
Add your observatory using Setup/Observer Location menu
Update the <Neocomet>/macros/audela_main.tcl or prism_cfg.pgm according to the tool you’ll use (AudeLA or Prism) and with the characteristics of your setup.

Launch AudeLA
Click on File/Run a script and select the file neocomet.tcl
Update your configuration according to the objects you want to observe and with your conditions of observation.
Choose a working directory <work> where you’ll find the results of your job and where you’ll store your configuration file(s).

First select a low limit magnitude and short exposures to get an idea of the maximum of observable objects.
Click Apply and have a look to the Console to see a list of objects selected for programmed observation.
(NB : unitary exposure times will be rounded to 10s, 20s, 30s then 1mn, 2mn, 3mn etc …)
You can then examine the observation scripts that were generated in the directory <work>/res_<cfg>:

(<cfg> = cfg at 1st run or your loaded config file name)

The ephemeris have been backed up in the <work>/tmp/coords_*.txt files. You can modify them to update the magnitudes that are often approximate, check that the interesting objects to observe are present, delete objects... Pay attention, this file automatically regenerated if you change the start time of the observations !
Then choose most likely observation parameters (magnitude limit, time and number of exposures...)

You can also have the program automatically calculate the exposure parameters depending on the moving speed of each object and its magnitude. The determined number of exposures (so, the whole exposure time) will ensure the previous both criterions to be respected.
If you have a list of objects to be observed (whatever their magnitude) put them into a <work>/<objects_list>.txt file (see attached example) and select it in the interface.
Then click Apply and check the list of objects that will be observed as well as the unused idle time.
Adjust observation parameters until you are satisfied with the result (observed objects, little or no idle time...).
Differential speeds : if your mount support them they will be applied only into the Prism script. More, for fast mover objects, exposures number will be rounded to a multipe of 4 (i.e. 4n) and 2 short exposures (10s) will be taken to avoid trailed stars and allow correct astrometry. They will be taken in the middle of each of the 2n pictures set.
Check your script and, if you want, update it to adjust some parameters, correct exposures (making sure that the object is always observable !), disengage the observations synchronization on the scheduled time (Prism or AudeLA scripts check always that the observation is possible before moving the mount and launch exposures), etc…

to make a mosaic of images (useful for large objects or for low accuracy mounts !)
to make flats at the end of session and according to the height of the Sun

Do not hesitate to modify or update the scripts if you want (e.g.: addition of flats for Prism, focus command ...)
Before the night of observation, try to simulate script execution (use TestScript=1 into prism.pgm) to verify that everything goes as planned and, in particular, that the mount does not improperly move ! The responsibility of the authors cannot be engaged in cases of misuse of the script !
NB: it may be requested to set the time of the PC that will execute the script of observation in UT...

If you use preprocess option (Prism only) you must put the master pictures (darks …) into a folder named binX (X=binning=1,2,3 …) under the one specified into prism_cfg.pgm. They must be named, for exemple : bias_-20C.fits, dark_10s_-20C.fits, … , flat.fits

Description of the algo 1 selected to observe an object at a time T :

It has not already been observed
It is visible between T and T + Texpose
It has the lowest elevation among those whose elevation is maximum or, if not candidate:
It is closest (temporally) of its culmination or, if with identical culmination (at end of night for example):
It has the greatest elevation
And, if no candidate, it increments T

(potentially greatest number of observed objects)

Remove the dead time by automatically increasing the number of exposures (pay attention to the risk of inadvertent mount flip or to observe under the horizon !)
Into necomet_prg.tcl add the new algo:

Develop all possible combinations of observable objects and choose the one giving the maximum observable objects at maximum average height
Observe in priority objects of less visible time

Authors :

- Alain Klotz
- Raymond Zachantke

- Alain Maury (Prism scripting)
- Thierry Noël (thierrynoelpublic@mailo.com)