  Observations performed by INTEGRAL are typically subdivided in kilo-seconds
individual pointings. A mosaic software has been developed at the Danish Space
Research Institute to combine sky images from different pointings with
significantly improved capabilities compared to the available software. This
software takes account of the specifics of the JEM-X instrument, such as the
vignetting effects due to its collimator and its mask structure. It calculates
the weighted contribution of each pixel from each input sky images to be added
in order to maximise the signal/noise ratio of each pixel in the combined sky
image. The software produces mosaic'ed maps with the source signal and of the
noise in each pixel, and is used as a tool to find new X-rays sources that are
too weak to be seen in individual pointings.
