CARA stands for Cometary ARchive for Afrho (previously named  Cometary Archive Amateur Astronomers).

It is a  project born with the goal to develop a standardized observing and reduction method mainly devoted to perform CCD comet imaging and photometry of comets with small and medium size telescopes, typical of amateur astronomers equipments. 

Comets are a typical targets for amateur astronomers imaging, astrometry  and photometry. As tradition photometry is mainly  devoted  to visual total magnitude estimates and now complented by CCD digital techniques.
Our basic idea was to run a bit more specialized program to extract more information from CCD digital images.  The collected data eventually are entered in a database in a format ready to be used for a scientific analysis.  Our basic method allows also to  acquire high quality imaging useful for morphological investigations too.

Of course amateur astronomers data are on an average less accurate than the ones obtained with professional equipments fron high quality sites. But non professional data can grant a more long term continuing monitoring around specific targets, complementing professional results.

The approch used in photometry differs from the classical visual technique. Measures are taken using  photometric filters with pass-bands usually dominated by the reflected sunlight (red and near infrared wavelenghts). Instead of classical total magnitude  the Afrho or Afρ quantity is calculated by means of differential aperture photometry.
Afρ is a quantity largely used by professional astronomers to study  dust in cometary comae. 
This quantity is less intuitive to amateur astronomers  than classical magnitudes but allows a better investigation around the dust in comets.  The results of our progam have been widely checked against professional data finding always a fairly good agreement.

The CARA project was born as a consortium of amateur astronomers suported by some professional specialists.  The partecipation is free providing to agree to our policy.