Water losses have a high environmental impact in terms of natural resources depletion (water, energy, ecosystems). This work aims at developing an airborne water leak detection surveillance service to provide water utilities with adequate information on leaks in water transportation mains outside urban areas. As a first step, a series of measurement campaigns were performed with hyperspectral cameras and a thermal infrared camera for selecting the most appropriate wavelengths and combinations thereof for revealing at best high moisture areas and artificial leaks. Further measurements will be performed with thereby optimized instrumentation onboard a plane and a UAV in an operational environment.

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We report on an intense red emission spectrum which is obtained when a highconcentration flow of chemically produced metastable oxygen 02('Ag) passes over various heated metals and on a search of a chemical-laser effect. The visible and IR emissions show that the reaction could occur in two steps and probably involves small polyatomic molecules; some possibilities are discussed. Despite the intense, uniform and extended active zone observed using a high-power chemical 02('Ag) generator, we did not obtain laser oscillation, contrarily to recent results. Further developments are in progress in order to prove the potentiality of this system as a visible chemical laser.Metastable 'Ag oxygen is now well-known as the energy carrier in the chemical oxygeniodine laser (COIL). Large amounts of 02('A3 can be produced by chemical means, and with improved chemical generators delivering more than 80% of excited oxygen lasing at powers up to several kW has been obtained in the last few years. Like other existing chemical lasers (HF, DF), the COIL emits in the infrared, and many efforts have been made to find a chemical laser in the visible range, without success until now.Recently, Yoshida et al. [ll have reported on an intense red emission appearing under certain conditions in the active region of a COIL. Laser gain at 703nm[1] and laser oscillation at this wavelength of several tens of microwatts [2] have been reported by these authors. These results suggest that such a system could be a good candidate for a highpower visible chemical laser.Yoshida was the first to observe the bright red emission of the flame. The maximum signal is obtained when a high-concentration flow of metastable oxygen Oz('Ag) passes over a heated copper rod ((200 + 400) "C) and could be due to the emission of an oxygen dimer or [I, 21.

Optimization t e s t s are being conducted on a high power chemical oxygen iodine laser. Optical diagnostics were developed t o monitor variations i n laser medium species. Presently 570 watt l a s e r output was obtained and a laser power o f a t l e a s t one k i l o w a t t i s expected.