Paul Ruffle at Starry Night
Variation in Noise Addition of Data

Edge Cloud 1 - HCO+ Spectra Movies

Variation in noise (rms) during 6 hours

EC1 HCO+ spectra rms

The first movie shows how the noise varied during 372 minutes of observing HCO+ in Edge Cloud 1 (EC1) at the Onsala 20m telescope in May 2005. Note how the system temperature (Tsys), and hence noise, changed as the weather improved or deteriorated.

Addition of data to improve signal to noise ratio

EC1 HCO+ spectra intensity

The second movie shows that when the same line intensity data is progressively added together, the signal to noise ratio improves (2t → √2), and the noise (rms) is reduced from around 2 K to 28 mK, and a clear 5σ detection of HCO+ at 138 mK is revealed in EC1.

(QuickTime required to play above MP4 movies)


Home > Astronomy > Spectra Movies > Return to Top