Aerosol optical thickness (AOT) calculations

To use this form, you must supply the latitude and longitude of your observing site, the date, and the time (UT). You must also know the calibration constants (Vo) for your instrument. The Earth/sun distance is also required, in units of astronomical units (AU). For an approximate calculation, use a value of 1. Earth is farther from the sun in the summer than in the winter. In mid-June it is about 1.016 AU from the sun. In mid-January, it is about 0.984 AU from the sun.

NOTE: No error checking is done on these values.
Your sun photometer calibration constant (Vo): V
Your site coordinates: latitude decimal degrees   longitude decimal degrees (US is negative)
month:    day:    year (4 digits):     atmospheric pressure: mb
time (UT): hr min sec
Channel, red (r) or green (g):
dark voltage: V    sun voltage: V



JD:     Earth-sun radius: AU     relative air mass: (dimensionless)
solar elevation angle: degrees
aerosol optical thickness (AOT): (dimensionless)     percent transmission: %

Click here when you're done.

NOTE: This page is under development and subject to change without notice.