trihedral

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trihedral

[trī′hē·drəl]
(mathematics)
Any figure obtained from three noncoplanar lines intersecting in a common point.
References in periodicals archive ?
Four targets, including a landmine and three 0.3 m trihedral reflectors, are disposed in region A along the flight direction.
Therefore, discrimination of landmine from trihedral by reflectivity intensity is very hard.
J., "Calibration of polarimetric radar images using only image parameters and trihedral corner reflector responses," IEEE Transactions on Geoscience and Remote Sensing, Vol.
Before we give the definition of AR, a coordinate system for trihedral is established as is shown in Fig.
As a result, AR is the function of the pose angle of trihedral OP, and the incident angle [[theta].sub.T] is an important parameter in developing the estimation method.
In this section, a parametric back-scattering model is used to determine the AR [rho]([[theta].sub.P]; [[theta].sub.T]) in the echo-domain according to Equation (2) when a trihedral is in different pose angles.
To estimate the pose angle of a trihedral when radar operates in MIMO array measurement configuration, we make use of parametric models of canonical shapes for bistatic radar.
According to the literature, the square trihedral peak scattering occurs at [[beta].sub.T] = [[beta].sub.R] = [tan.sup.-1](1/[square root of 2]) [??] [[beta].sub.0], not at [beta] = 45[degrees].
where the length of the trihedral along each edge is assumed to be equal to H and A = 2[square root of 3][H.sup.2].
The definition of AR provides us a direct way to estimate the pose angle of a trihedral in the echo-domain.
As mentioned above, echo-domain method has a limitation constrained to process echo data from only one trihedral. But in a man-made building, there are often many trihedra.
The pose angles of the left wall-wall-floor trihedral [[theta].sup.L.sub.P], = -31[degrees] and the right wall-wall-floor trihedral [[theta].sup.R.sub.P] = 28[degrees] are depicted in Fig.