  With the rapid developments in the exoplanet field, more and more terrestrial
exoplanets are being detected. Characterising their atmospheres using transit
observations will become a key datum in the quest for detecting an Earth-like
exoplanet. The atmospheric transmission spectrum of our Earth will be an ideal
template for comparison with future exo-Earth candidates. By observing a lunar
eclipse, which offers a similar configuration to that of an exoplanet transit,
we have obtained a high resolution and high signal-to-noise ratio transmission
spectrum of the Earth's atmosphere. This observation was performed with the
High Resolution Spectrograph at Xinglong Station, China during the total lunar
eclipse in December 2011. We compare the observed transmission spectrum with
our atmospheric model, and determine the characteristics of the various
atmospheric species in detail. In the transmission spectrum, O2, O3, O2-O2, NO2
and H2O are detected, and their column densities are measured and compared with
the satellites data. The visible Chappuis band of ozone produces the most
prominent absorption feature, which suggests that ozone is a promising molecule
for the future exo-Earth characterization. The individual O2 lines are resolved
and O2 isotopes are clearly detected. Our new observations do not confirm the
absorption features of Ca II or Na I which have been reported in previous lunar
eclipse observations. However, features in these and some other strong
Fraunhofer line positions do occur in the observed spectrum. We propose that
these are due to a Raman-scattered component in the forward-scattered sunlight
appearing in the lunar umbral spectrum. Water vapour absorption is found to be
rather weak in our spectrum because the atmosphere we probed is relatively dry,
which prompts us to discuss the detectability of water vapour in Earth-like
exoplanet atmospheres.
