Convert Arcseconds to Microradians
Convert Arcseconds (″) to Microradians (µrad) instantly and accurately.
Conversion Formula
µrad = ″ × 4.848136811
About Arcseconds
An arcsecond (″) is 1/3,600 of a degree - π/648,000 rad ≈ 4.848 × 10⁻⁶ rad. It is the fundamental resolution unit of classical astronomy and geodetic surveying. The Hubble Space Telescope delivers ~0.05″ resolution; atmospheric seeing at excellent sites gives 0.4-0.6″. Stellar parallax of Proxima Centauri is 0.7687″, defining its distance of 1.3009 parsecs. The parsec is defined as the distance at which 1 AU subtends exactly 1 arcsecond - giving 1 pc = 3.0857 × 10¹⁶ m. 1″ = π/648,000 rad ≈ 4.848 µrad.
About Microradians
A microradian (µrad) is one millionth of a radian (10⁻⁶ rad ≈ 0.206265 arcseconds). It is the standard unit for small angles in precision optics and structural monitoring. A 1 µm wavelength beam from a 1 mm aperture has a diffraction-limited half-angle divergence of ~1 µrad. Atmospheric seeing for ground-based telescopes is typically 2.4-9.7 µrad (0.5-2 arcseconds). Autocollimators resolve angular deviations to 0.05-1 µrad for machine tool alignment. Building tilt monitoring tracks µrad/day. 1 µrad ≈ 0.2063″ = 0.2063 arcseconds.
Quick Reference Table
| Arcseconds (″) | Microradians (µrad) |
|---|---|
| 1 ″ | 4.84814 µrad |
| 2 ″ | 9.69627 µrad |
| 5 ″ | 24.2407 µrad |
| 10 ″ | 48.4814 µrad |
| 25 ″ | 121.203 µrad |
| 50 ″ | 242.407 µrad |
| 100 ″ | 484.814 µrad |