  The all sky survey run by the Galaxy Evolution Explorer (GALEX AIS) mapped
about 85% of the Galaxy at ultraviolet (UV) wavelengths and detected the
diffuse UV background produced by the scattering of the radiation from OBA
stars by interstellar dust grains. Against this background, diffuse weak
structures are detected as well as the UV counterparts to nebulae and molecular
clouds. To make full profit of the survey, unsupervised and semi-supervised
procedures need to be implemented. The main objective of this work is to
implement and analyze the results of the method developed by us for the blind
detection of ISM features in the GALEX AIS . Most ISM features are detected at
very low signal levels (dark filaments, globules) against the already faint UV
background. We have defined an index, the UV background fluctuations index (or
UBF index), to identify areas of the sky where these fluctuations are detected.
The algorithm is applied to the images obtained in the FUV (1344 -1786
Angstroms) band since this is less polluted by stellar sources, facilitating
the automated detection. The UBF index is shown to be sensitive to the main
star forming regions within the Gould's Belt, as well as to some prominent
loops like Loop I or the Eridanus and Monogem areas. The catalogue with the UBF
index values is made available on-line to the community.
