The Watershed Allied Telemetry Experimental Research (WATER) is a simultaneous airborne, satellite-borne and ground based remote sensing experiment in the Heihe river basin, which is the second largest inland river basin in the arid region of northwest China. WATER consists of the cold region, forest, and arid region hydrological experiments and its field campaigns include two phases. The first phase is an intensive observation period lasting from March 7 to April 12 , 2008 for the cold region and the second phase is that from May 15 to July 22 for the forest and arid regions, 2008. The second step is introduced in this paper. The scientific objectives and research tasks are briefly reviewed. The airborne sensors include microwave radiometers at L, K and Ka bands, imaging spectrometer, thermal imager, CCD and LIDAR. Seventeen missions were performed with 72-hour flying time. Simultaneous observations were performed in the foci experimental areas which include Dayekou watershed, Pailugou watershed, Huazhaizi desert, Yingke oasis, Zhangye city, Linze grassland, Linze station transitional zone. The sampling protocol, data acquirement and preprocessing, research advance and prospects are introduced in detail for these airborne and ground simultaneous experiments. 