DarkRidgeObservatory.org1 Eclipsing Binary Star Program, Hardware and Software Thomas C. Smith Director, Dark Ridge Observatory
DarkRidgeObservatory.org2 Observing Project Goals Specific Points of interest –Automated EB Observing Program –Automatic Observatory Operations –Automatic Data Collection and Reduction –System Health Notification Process Using equipment and software that is commonly available to the amateur, an automatic EB program of study will be carried out. –Telescope is a Meade 14” LX200GPS mounted equatorially on a heavy- duty wedge. –CCD Camera is an ST-7XE USB non-antiblooming, blue-enhanced system from SBIG. –Software is TheSky, CCDSoft, TPoint, and Orchestrate from Software Bisque also MIRA AP-7 from Axiom Research. Programming will utilize the ASCOM or RASCOM standard objects that integrate with the above software and hardware. Bisque.com / Axiom.com
DarkRidgeObservatory.org3 Observatory, Telescope and Mounting
4 ST-7XE CCD Specifications CCD Kodak KAF-0401E + TI TC-211 Pixel Array 765 x 510 pixels, 6.9 x 4.6 mm, Total Pixels 390,000 Pixel Size 9 x 9 microns Full Well Capacity (NABG) ~100,000 e-, Dark Current 1e¯/pixel/sec at 0° C Non ABG, Shutter Electromechanical Exposure 0.11 to 3600 seconds, 10ms resolution, Correlated Double Sampling A/D Converter 16 bits, A/D Gain 2.3e¯/ADU, Read Noise 15e¯ RMS Binning Modes 1 x 1, 2 x 2, 3 x 3 Pixel Digitization Rate Up to 420,000 pixels per second Full Frame Acquisition ~1 second Specs Per SBIG
DarkRidgeObservatory.org5 ST-7XE Optical Specifications Using an 8" f/10 system Field of View 12 x 8 arcminutes Pixel Size.9 x.9 arcseconds Limiting Magnitude Magnitude 14 in 1 second (for 3 arcsec FWHM stars) Magnitude 18 in 1 minute Specs Per SBIG
DarkRidgeObservatory.org6 ST-7XE System Specifications Cooling - standard Single Stage Thermoelectric, Active Fan, Water Assist Ready -45 C from Ambient Typical Temperature Regulation ±0.1°C Power 5 VDC at 1.5 amps, ±12 VDC at 0.5 amp Computer Interface USB Computer Compatibility Windows 95/98/NT/2000/Me/XP Guiding Dual CCD Self-Guiding Specs Per SBIG
DarkRidgeObservatory.org7 ST-7XE Physical Dimensions Optical Head 5 inches diameter x 3 inches 12.5 cm diameter x 7.5 deep 2 pounds/0.9 Kg CPU All electronics integrated into Optical Head, No CPU Mounting T-Thread, 1.25" and 2" nosepieces Backfocus 0.92 inches/2.3 cm Specs Per SBIG
DarkRidgeObservatory.org8 Running System Flow Diagram This is a preliminary flow diagram of a normal observing session run. The system is continuously performing self monitoring to ensure that appropriate actions are taken.
DarkRidgeObservatory.org9 System Shutdown Process When the system has completed the programmed loops or an error condition is raised, the system will enter the shutdown process.
DarkRidgeObservatory.org10 Flow Control System: Environmental Monitoring System The environmental monitoring system will be responsible for the following items –Cloud cover and precipitation anticipation –OTA to Ambient delta-T measurements –Wind speed –Lightening strike detection –Ambient light conditions –Smoke / Fire detection system
DarkRidgeObservatory.org11 Flow Control System: Observatory Operations The observatory operations system will be responsible for the following items –Roof position detection –OTA park-position detection –AC/DC power monitoring –Internal lighting system control –Observatory “flat” screen illumination and filtering
DarkRidgeObservatory.org12 Flow Control System: Telescope Control The telescope control and positioning system will be responsible for the following items –Telescope pointing and tracking –Target acquisition and centering –Auto guiding (using the ST-7XE guider) –Telescope park and shutdown initiation
DarkRidgeObservatory.org13 Flow Control System: CCD Camera and Filter Wheel The camera and filter wheel system will be responsible for the following items –Creating calibration “dark” and “flat” exposures –Filter position indexing –Auto guiding system control signal generation –Target exposure / integration –Data signal conversion and storage
DarkRidgeObservatory.org14 System Shutdown: Park Scope The telescope control system will position the telescope into the “park” position in preparation for roof closure
DarkRidgeObservatory.org15 System Shutdown: Observatory Roof Closure Once the telescope is “parked” the roof closure system will: –Verify the roof is clear to close using a two-detector system that utilizes infrared detectors. –Close the roof using the DC motors to the fully shut position as indicated by redundant limit switches –Power down the observatory roof circuits
DarkRidgeObservatory.org16 System Shutdown: Data File transfer The data file transfer system will be responsible for the following items –Moving the collected data files onto a server utilizing a wireless network. –Verify the file move succeeded –Delete the local file copy –Initiate the remote data analysis software –System health and heartbeat message creation –System error message creation and notifications
DarkRidgeObservatory.org17 Procedures Detailed system startup, operation and shutdown procedures will be created and followed to ensure data integrity and repeatability Target or opportunity program suspension procedures and processes will be available with “smart” subsequent program step resumption FOR MORE INFO... Procedures will be maintained on the project web site at
DarkRidgeObservatory.org18 Schedule –Hardware and observatory construction (Jun 2003 – Oct 2003) –System testing and automation processes (Sept 2003 – Dec 2003) –Observing program initiation (Sept 2003 – Nov 2003) –Scientific program of study (Sept 2003 – Kepler Launch)