A New Software Application for Allsky Camera Networks IMC 2013 August, 2013 Chris Peterson Cloudbait Research Associate, DMNS
Current System 30 fps NTSC camera Fisheye lens Acrylic dome Matrox Meteor II PCI framegrabber MetRec capture Proprietary processing
Colorado Allsky Network
Goals Cloudbait Design Goals Reliably detect nighttime meteors with low false-alarm rate. Near real-time communication of events to server. Open source. Established, reviewed, publicly available analysis code. Support most video digitizers and digital video cameras. Modest hardware performance requirements. Minimize network security issues. Engaging for camera operators. Web access data portal.
Strategy Cloudbait Video acquisition / meteor detection client. Analysis server. Client: Windows. Design Strategy Client: two-pass; high priority detection, low priority filter. Client: all communication with server via HTTP. Client: all instructions from server acquired by polling. Server: PHP coding; no executable modules. Server: MySQL database management. Server: Web interface (private, public, management).
Client Module Video acquisition: DirectX video library. Real-time detection via motion detection (high priority). Post-filtering by line fitting (low priority), frames & events Local processing: endpoints to equatorial coordinates. Local processing: peak magnitude calculation. Local processing: event duration. Event data uploaded to server via HTTP (no video). Client polls server via HTTP for video upload command. Automated start/stop, unattended operation supported.
Client Module Utilities Astrometric calibrator (cubic altitude fit, linear azimuth). Post processor. Data viewer.
Server Module - Logger PHP code running on web server (typically Linux/Apache). Receives and logs events from client stations. Detects possible multiple station events. Sets flags to trigger client uploads of interesting events. Logs all data using MySQL. Email and Twitter interface for event notification.
Server Module - Analyzer Radiant and timing calculator accepts station coordinates, event start and stop altaz, event start and stop time. Calculates geocentric atmospheric trajectory for each station pair combination. Calculates average velocity. State vector calculator applies required coordinate transforms utilizing NOVAS (C to PHP port, Bangert et al), ITRS to GCRS to ecliptic coordinates. State vectors are calculated for each station pair combination. Orbit calculator accepts state vector(s), calculates heliocentric positions for Earth, Moon, and planets utilizing the VSOP82 algorithm, applied to MERCURY integrator (Fortran to PHP port, Chambers et al); backward integration to stable elements.
Server Module - UI User database manager allows privileged access to specific data categories, data embargos, and system management. Database viewer view by date, camera, location, duration, brightness. Calls analysis module to determine orbit. Orbit graphical display (Java, Ajiki et al). Event video viewer (HTML5). Witness report form and database manager.
Server Module - UI
Results Three camera subnetwork operating since May 2013.
Results False event detection is much improved. Sensitivity compares to existing Metrec-based system.
Results Most captures to date are sporadics difficult to assess. Multistation shower captures 22 SDA, 11 CAP, 30 ETA, 25 PER. Mean SD on semi-major axis 15% probably stems from poor initial velocity estimate based on average velocity. PHP coded math routines give identical results to both C and Fortran coded routines. Tested successfully with 1280 x 960 Firewire 30 fps camera.
Still in Development Automate frame-by-frame analysis to get light curve and v(t). Add integrating sphere photometer support. Evaluate integrators with C source code. Evaluate client-side or PHP library video converters. Write scripted version of orbit display tool. Use higher order astrometric solution (public code?) Use better technique for analyzing data from >2 stations.
Questions