In 1996, NIES, in Tsukuba, Japan, developed an automated elastic scattering lidar (EL) system that could operate continuously without human intervention. At that time, only the total backscatter signal intensity at 532 nm () was recorded, and only aerosols and cloud layers could be identified. In 1999, the system was modified so that the polarization state of the backscattered light could also be recorded, allowing aerosol particle shapes to be investigated. By this modification, the NIES automated lidar system acquired the capability to distinguish mineral dust particles from anthropogenic particles and ice particles in cirrus clouds from water droplets in convective clouds. In 2001, an initial lidar network was constructed for the ACE-Asia campaign,6 an important aim of which was to investigate the distribution of Asian dust. For ACE-Asia, NIES operated lidar observatories at Tsukuba, Nagasaki, and Beijing and collaborated with other lidar observatories in Japan.7,8 Since then, the number of NIES-type lidar observatories, which follow a mostly uniform operational strategy, has increased; at present, AD-Net comprises a total of 20 observatories in East Asia (i.e., in Japan, Korea, China, and Mongolia). Figure 1 shows the locations of AD-Net lidar observatories in operation as of July 2016. Nowadays some lidars were modified to Raman lidar (RL) or multiwavelength Raman lidar (MRL) systems (see Sec. 3). However, the data treatment for elastic scattering channels of such lidars is the same as that for EL. Thus, we describe EL system at first (Sec. 2.2) and then introduce the common data processing procedures on elastic scattering channels in Sec. 2.3.