Observing Techniques
Beating the atmosphere and the detector — lucky imaging, speckle imaging, stacking, and fringe tracking.
- Fringe TrackingObserving technique
The real-time control that keeps the interference fringes of an optical interferometer stable against the atmosphere's constantly-changing path lengths, so faint targets can be observed for longer. Without it, the fringes wash out in a fraction of a second.
- Image StackingObserving technique
Combining many exposures of the same field to build up signal and average down noise, reaching far fainter objects than any single frame — the foundation of deep imaging, from amateur astrophotography to the deepest survey fields.
- Lucky ImagingObserving technique
Taking a rapid burst of very short exposures and keeping only the few sharpest — the lucky moments when the atmosphere happens to be still — then combining them. A simple way to reach near-diffraction-limited resolution on modest telescopes without full adaptive optics.
- Speckle ImagingObserving technique
Recovering fine detail from the fleeting speckle pattern that the atmosphere breaks a star's image into, by taking many very short exposures and reconstructing the true image statistically. It resolves close double stars and fine structure below the atmospheric blur.