The LAP (High Power Laser) research project, funded by the Italian Ministry of Defense, concerns the study, the design and the implementation of in-air propagation tests of the 10TW laser pulse of the ILIL laboratory. The aim is defining the conditions of intensity, divergence, temporal and spatial profile such as to optimize the transfer of laser energy in the air over great distances (100m – 2 Km). The project involves the modeling of the phenomenon through numerical hydrodynamic and Particle-in-Cell (PIC) codes, followed by experimental tests of free propagation. The work includes systematic studies of the effects of ionization and self-focusing in air, also by controlling the transverse phase of the beam, thanks to the use of adaptive systems. The main aims of the study are the optimization of efficiency and the control of propagation over distances much greater than the length of diffraction. The most promising applications of this study is the LIDAR (Light Detecting and Ranging) technique, used for atmospheric studies, such as the detection of the concentration of some chemical species in the air.