Device for measuring directional transmission of light in vegetation cover for determining index surface of cover, has sensor whose collecting solid angle covers zenith angle and azimuth angle ranging between specific degree

摘要

The device (1) has a radiation sensor (3) arranged such that its aiming direction (3a) defines a zenith angle (A) included between 45 and 60 degree along a longitudinal axis (2') of a vertical support (2). Another radiation sensor (4) is arranged such that its aiming direction (4a) defines another zenith angle included between 15 and 45 degree. A third zenith angle (C) is defined in the aiming directions of the radiation sensors. A collecting solid angle of each sensor covers a fourth zenith angle ranging between 5 and 15 degree and an azimuth angle ranging between 10 and 45 degree. An independent claim is also included for a method for measuring directional transmission of light in a vegetation cover.