Up to recently, the cloud cover, and the cloud's properties (type, altitude…) were, in most of the cases, parameters estimated by human observers, with as consequences measurements performed mainly during daytime and highly uncertain in terms of accuracy and repeatability. More recently some methods using digital photography and/or ceilometer's techniques begins to appear, but remain experimental and/or of marginal use.

In this presentation, we will illustrate a new techniques based on the use of some "off the shelf" IR thermometers. The determination of the cloud cover in all conditions (day and night) will be presented and compared with results obtained by other techniques. Estimations the altitude of the first cloud layer and, in broken clouds conditions, of the second one (with an accuracy of a few hundred meters) will also be discussed. Some recent results show that the cloud typology could also be reached by this method; this aspect will be outline but require new steps of development in our future program.