Transcript softwares and past experience

The TAROT observatory
presented by Alain KLOTZ –
Centre d'Etude Spatiale des Rayonnements Toulouse
& Observatory of Haute-Provence
Data acquisition and telescope control: softwares and past experience
Build in 1998 by CNRS. Fully robotized.
D=25 cm f=85 cm, CCD Andor 2x2k
Field = 1.9x1.9°, sampling 3.3 arcsec/pix
About 12 GRBs/year
Variable stars
Minor planets
Follow up of ToO
SOME RULES FOR ROBOTIC OBSERVATORIES
Basic idea : I do other things during nights instead pushing buttons !
1st consequence : There is a huge amount of data to process and now
I spend nights to push buttons to reduce data !
2nd consequence : I spend a lot of daytime to select many targets.
Now, I am occupied nights (by processing) & days (for selections) !
Evoluted idea : The robotic observatory MUST include the SCHEDULE
and the data REDUCTION => a robotic observatory is not only a
computed controled telescope but there is also a lot of software work!
The TAROT observatory – A GLOBAL VIEW
Environnement : housekeeping , permanent internet, electric power
Requests
Planning
Driving
Processing
Data
Hardware
The TAROT observatory - HARDWARE
Electricity
1 power inverter (onduleur)
drived switches (disjoncteurs)
Flat-field lamp
Motors
5 motors + encoders + protocol
(roof, a, d, filters, focus)
Mechanics
Rolling roof
Robust fork
Cogwheels (roue, vis sans fin)
Filter wheel (BVRI C)
Meteo station (rain, humidity, wind)
Flat-field screen
Computers
3 PCs (OS Win32)
Webcam
The TAROT observatory - SOFTWARE
For each PC
VNC, FileZillaServer (FTP), Apache (HTTP), AudeLA
AudeLA (A.U.D.E Logicel d'Astronomie)
A free GNU public software : http://audela.ccdaude.com
C/C++ ANSI for basic functions (image processing, celestial mechanics)
called by Tcl/Tk scripts for nice batchs
Robotic application for AudeLA
A Tcl/Tk event loop that calls C/C++ functions
input (e.g. a raw image)
output (e.g. processed image)
CGI to process web formulars (to acces to requests & processed data)
The TAROT observatory - PLANNING
USERS
User account, Priority (0 to 100), Quota (0% to 100%)
Must publish or teaching.
Fit TAROT Tcl/Tk scripts for each user program
Send their program using a customized TAROT web interface
REQUESTS & SCENES
Conversion of the user program into a common description :
An observation REQUEST is composed by a series of SCENES
A SCENE is the basic observation block :
a slew to coordinates
1 to 6 exposures (time + filter)
constraints (range of dates, minimum elevation, moon)
SCHEDULE
Selection : sorts scenes by priority and by date of set.
Insertion : each sorted scene is included if the user quota is not over
~95% of the night is occupied and every user is satisfied
The TAROT observatory - DRIVING
THE MAIN LOOP
Checks that every hardware module is alive and ready
Ask to the planning the next scene to observe
Convert scene parameters
Pointing model (telescope flexures, etc.)
Convertion of angles to motors units
etc...
Send converted scene parameters to each hardware component
SECURITY
An independant software checks that everything is alive
The TAROT observatory - PROCESSING
COMMON PROCESSING
Dark and flat corrections
Special filter in the case of trailed images (GRBs, occultations, satellites)
Sextractor list
USNO-A2 list
Match the lists to compute WCS keywords for astrometry
Complete header informations (FWHM, number of matched stars, etc.)
Archive of FITS image and the corresponding Sextrator list
SPECIAL PROCESSING
Reduce data from image to a form directly usable for the user
e.g. (julian day, magnitude) for the RRLyr program
e.g. the image of star trail for a star occultation by an asteroid
e.g. Web pages to help to analyze quickly a GRB event
GLOBAL VIEW OF THE TELESCOPE CONTROL
Légend :
element visible by users (WEB)
software
REQUESTS
SCHEDULER
hardware
GRB ALERTS
SEQUENCER
SUPERVISION OF THE OBSERVATORY STATES
Data
USERS
SECURITY
MOTORS, METEO, CAPTORS, POWER SUPPLY
Bases
of
TAROT
MOTORS, METEO, CAPTORS, POWER SUPPLY, CAMERA
PROCESSED IMAGES
STANDARD IMAGES PROCESSING
PROCESSED DATA
SPECIALIZED DATA PROCESSING
The TAROT observatory – STATISTICS: 50 000 images / years
Efficiency : 90% of time ready to observe
The TAROT observatory – SKY COVERAGE
The TAROT observatory – SOME RESULTS
GRB 050730
z=4
Supernova
NGC 6946
ASTRA
occultation of star by Wallia
The TAROT observatory – A SECOND OBSERVATORY IN CHILE