SAM Specifications


Quantity SAM


(and aerosols)

Size Range

~ 5 - 100 Ám

OD range -direct

0 to 10

up to 100

Minimum aureole angle from disk edge


Measurement sampling

~10 sec


Field of View



OD measurement accuracy (absolute)


OD measurement precision (relative)


Our Technical Brochure may be downloaded here.
SAM is a precision solar tracking instrument that utilizes multiple cameras (filtered at 670nm) and a spectrometer to simultaneously measure the solar aureole caused by forward scattering and the optical depth of clouds.



bulletThe acquired data are processed on-site to deliver optical depths, aureole profiles and column water vapor
bulletAutomated software is also available from Visidyne for data validation and analysis, and to produce corrected optical depths and particle size distributions (effective particle size)

SAM instrument suites include an integral, temperature-controlled VIS/NIR Sun spectrometer. It is a CCD based sensor that uses a Czerny-Turner optical bench. Its pointing and exposure durations are automatically controlled by the software, and the instrument electronics has capability for automatic subtraction of dark pixel values.

Wavelength range = 400 to 950nm
Resolution = 1/3 nm
Dynamic range = 1300:1 for a single acquisition, and >108 for the system
Signal-to-noise = 250:1 at full signal

Copyright 2008 - Visidyne, Inc.