Calcolatore Tolleranza Errore di Inseguimento
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Max Periodic Error
1.5400 arcsec
Max Periodic Error vs Worm Period
Formula
Tracking Error Tolerance
For unguided astrophotography, the mount's periodic error (PE) must be small enough that stars do not trail beyond the pixel scale.
Formula
PE_max = pixel_scale * drift_pixels
The drift rate limit is PE_max divided by the worm-gear period.
Esempio Risolto
0.77 arcsec/px scale, 2 px acceptable drift, 480 s worm period.
- 01PE_max = 0.77 * 2 = 1.54 arcsec
- 02Drift rate = 1.54 / 480 * 60 = 0.1925 arcsec/min
Domande Frequenti
What is periodic error?
PE is the back-and-forth tracking error caused by imperfections in the mount's worm gear. It repeats every worm cycle (typically 4 to 10 minutes).
How can I reduce PE?
Use periodic error correction (PEC), autoguiding, or a mount with a high-quality worm gear. Belt-driven mounts often have lower PE.
Is autoguiding always necessary?
For long focal lengths or multi-minute exposures, usually yes. At short focal lengths (under 200 mm) many mounts track well enough unguided.