The DARS (Drone‐Based Aerosol Remote Sensing) System: A Solar Spectrometer Platform—Instrumentation, Calibration, and First Experiments

Accurate, high‐resolution measurements of Aerosol Optical Depth (AOD) are essential for radiative forcing assessment and air quality management. However, a critical observational gap exists between ground in situ monitoring networks (e.g., AErosol RObotic NETwork) and satellite products compromised by low revisit frequency, and sparse resolution. To bridge this gap, we present a novel Drone‐based Aerosol Remote Sensing (DARS) platform equipped with a designed solar Spectrometer, observing direct‐sun, multi‐wavelength radiation measurements. The system is cross‐calibrated against a reference sun photometer and employs a comprehensive quality assurance protocol to ensure data reliability under flight conditions. We evaluate two operational modes: a Landing Detection Mode (LDM) for stabilized measurements and a Hover‐to‐Cruise Mode (HCM) for in‐flight data collection. LDM achieves exceptional agreement with reference data ( R 2 > 0.94, RMSE <0.04). HCM performs robustly across varied aerosol loadings in eight field experiments, with R 2 from 0.69 to 0.99 and MAE between 0.001 and 0.07. Primary uncertainties, quantified via a process‐based error budget, are decomposed into calibration, drift, FOV diffuse, and stochastic terms, totaling 5.7%–10.3% of band‐averaged AOD—enclosing all validation records within the predicted envelope. The DARS platform effectively bridges spatial and temporal observational gaps, offering a flexible, accurate tool for targeted aerosol monitoring, pollution episode analysis, and validation of satellite and model products.