Thus for most purposes, it will be adequate for observation planning.
Some exceptions occur as follows.
To address this problem, observers should inspect POSS and 2MASS images or consult a model for the density of stars. For lines of sight passing near young massive stars, the contributions of H II regions and photo-dissociation regions will not be accurately traced by our interstellar cirrus map. However this method will only work for regions where the sky is bright. This is because our proposed model uses only a single spectral shape for the interstellar medium, whereas in fact the spectrum varies.