The SP-9 and SPM multiwavelength sun photometers are described and briefly characterized. The SP-9 sun photometer is designed for year-round monitoring of the spectral atmospheric transparency in the wavelength range 0.3-2.2μm in the regional network of stations. To implement the automatic measurement mode (unattended by operators), the instrument includes solar sensor, automatic sun pointing/tracking system, built-in GPS receiver and flash drive, and sensors of meteorological parameters. The SPМ portable photometer is a simplified version of SP-9 and is designed for the atmospheric transparency measurements under mobile conditions.
sun photometer, aerosol optical depth