Sequence Generator

Sequence Generator Pro automates astrophotography sessions by coordinating cameras (CCD, CMOS, Canon, Nikon), filter wheels, focusers, mounts, rotators, flatboxes, domes, roll-off roofs, and weather stations. The free Lite version provides advanced functions for beginners while the Pro version scales with user equipment. No internet connection required. Users modify automation parameters in real time, including automated target framing, meridian flip, in-sequence centering, and auto-focus capability.

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• Automated in-sequence centering. After each filter change or mount movement, the software recalculates and adjusts target centering to maintain the astronomical object in the exact same sensor position. This compensates for mechanical or thermal drift without manual intervention, preserving framing accuracy across multi-filter sequences.
• Temperature and filter-based auto-focus. The program executes focus routines whenever temperature changes by a user-defined threshold or when filters are switched. Independent focus curves for each filter are stored, along with optimal focuser positions, ensuring sharp images throughout the night regardless of thermal shifts or optical differences between filters.
• Target visibility scheduling. User enters celestial coordinates and the software calculates time windows when each target remains above the horizon without obstructions. The capture sequence prioritizes objects that will soon set, maximizing usable observation time under dark skies without manual replanning.
• Automated meridian flip. When the mount reaches the tracking limit before the meridian, SGPro executes a controlled flip: stops exposure, parks the mount, repositions to the opposite side, and resumes capture at the same framing. This enables continuous all-night sessions without operator presence or interruption.
• Flat frame calibration via twilight automation. The software connects to flatboxes or uses dawn/dusk sky to capture flat frames automatically. Optimal exposure time for 50% well depth is calculated, and these frames are scheduled at session start or end without breaking the light frame sequence.
• Hyperbolic focus for faint stars. Implements an algorithm measuring star curvature instead of star size alone, enabling precise focus even in star fields with few bright stars. This routine benefits dark nebulae, globular clusters, and galaxies with sparse star distribution.
• Weather condition event management. The monitor connected to weather stations (temperature, humidity, cloud cover, wind, rain) triggers automatic actions: pause sequence, close dome, park mount, and send email alerts. Reactivation occurs only when all parameters return to safe ranges, protecting equipment from sudden weather changes.
• Remote framing with camera rotator. User selects a rotation angle on screen and SGPro commands the rotator to align the constellation or nebula with the sensor axis. Live rotation preview allows composition adjustment without exposing the sensor, essential for mosaics and precise framing of narrowband targets.
• Complete equipment simulator for testing. Includes a simulation mode emulating mount, camera, filter wheel, and focuser. Beginners learn the complete sequence and test all functions without physical hardware. Equipment profiles are saved and later exported to real hardware, reducing configuration errors.
• Dome control synchronized with mount. For dome observatories, SGPro calculates real-time shutter position based on mount orientation. The shutter remains aligned with the telescope during tracking and during meridian flips, preventing obstructions and maintaining an unobstructed field of view.
• File management by target and filter. At session start, the program automatically creates subfolders named by object, date, and filter. Filenames include timestamp, exposure length, temperature, and focus parameters, facilitating subsequent stacking in software such as PixInsight or DeepSkyStacker without manual renaming.
• Adaptive dithering via autoguider. The software sends random displacement commands to the autoguider or mount between exposures. Dithering amplitude and frequency adjust based on seeing conditions and pixel scale, eliminating fixed pattern noise and hot pixels during post-processing image integration.

Development of Sequence Generator Pro began in 2012 by independent developer Ken McCorry under Main Sequence Software. The program is written in C# on the .NET framework, utilizing ASCOM libraries for device communication. First stable version released in 2013. DSLR support for Canon and Nikon cameras introduced in 2015. The free Lite version appeared in 2017. Active development continues with monthly maintenance releases. Core developers include Ken McCorry and Jared Willis, who maintain the codebase and technical documentation. The software architecture uses a multi-threaded sequence engine enabling simultaneous image acquisition, autoguiding, and environmental control without blocking operations.

Alternatives to Sequence Generator:

Astroart

Astroart is a software program for the processing and analysis of astronomical images.

Price: Free   Size: 114 MB   Version: 9.0 SP4   OS: Windows