VirtualSky Integration

VirtualSky provides an interactive, calibrated celestial sphere projection aligned with allsky fisheye imagery. It calculates equatorial, alt-azimuth, and planetary positions in real time based on the camera coordinates and timestamp.

The viewer is accessible in the web dashboard at:

https://<allsky-host>/indi-allsky/virtualsky

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Capabilities

• Celestial Mapping: Renders stars, major solar system planets, and constellations directly mapped to the fisheye field of view.
• Optical Alignment: Supports image circle sizing, optical axis center offsets, and compass orientation adjustments.
• Astrometric Calibration: Integrates with the astrometric lens_solver to compute and apply polynomial distortion models for precise star-to-pixel registration.

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Configuration Reference

Settings are managed in the web interface under Configuration → VirtualSky:

Parameter	Type	Default	Description
ENABLE	Boolean	false	Enables the VirtualSky rendering interface and metadata tracking.
MAGNITUDE	Float	6.0	Limiting visual magnitude for displayed stars. Higher values display fainter stars.
CONSTELLATIONS	Boolean	true	Renders constellation boundary stick lines.
CONSTELLATIONLABELS	Boolean	false	Renders constellation names.
SHOWSTARS	Boolean	true	Renders stellar objects within the limiting magnitude.
SHOWSTARLABELS	Boolean	true	Displays names for prominent navigational stars.
SHOWPLANETS	Boolean	true	Renders major solar system bodies (Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn).
SHOWPLANETLABELS	Boolean	true	Displays planetary name labels.
IMAGE_CIRCLE_DIAMETER	Integer	3500	Diameter (in pixels) of the lens projection circle on the camera sensor.
OFFSET_X	Integer	0	Horizontal pixel offset of the lens optical center relative to the sensor center.
OFFSET_Y	Integer	0	Vertical pixel offset of the lens optical center relative to the sensor center.
LATITUDE_OFFSET	Float	0.0	Positional offset in degrees to correct physical camera tilt or leveling error.
LONGITUDE_OFFSET	Float	0.0	Azimuthal offset in degrees to align camera North with geographic/astronomic North.
PRECESSION	Boolean	false	Applies Earth axial precession adjustments to equatorial coordinates.
RADIAL_DISTORTION	Float	0.0	Radial lens distortion coefficient for non-linear fisheye projections.
CALIBRATION_ENABLED	Boolean	false	Activates polynomial lens model coefficients computed by the astrometric solver.

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Astrometric Lens Solver Alignment

Manual alignment requires matching the optical center (OFFSET_X, OFFSET_Y) and compass rotation (LONGITUDE_OFFSET).

For optimal precision, utilize the built-in automated astrometric solver:

1. Capture an unclouded nighttime image with visible stars.
2. In the Image Viewer, select the lens solver utility.
3. The solver extracts star centroids, queries the embedded star catalog, fits WCS coordinates, and writes the calibrated polynomial distortion parameters (CALIBRATION) into the camera configuration.