Inventory of ground based data suitable for satellite validation

Summary
Identification and assessment of existing research and operational networks of ground based remote sensing techniques (e.g. lidar, radar, ceilometers, sun photometer, VIS/TIR cameras, UV scanners and cameras, infra-sound) with the capability to provide quantitative data products for natural hazards (e.g., volcanic ash, SO2 gas, desert dust, forest fires).