Convert between PolSAR storage formats

PolSAR observations are Hermitian positive definite matrices. SITSAR accepts them either as a complex array of dimension m x m x n or as an n x p complex matrix in which each row stores the \(p = m(m+1)/2\) distinct entries in the order \(C_{11}, \ldots, C_{mm}\) (the intensities) followed by the upper triangle \(C_{12}, C_{13}, \ldots, C_{23}, \ldots\). For \(m = 3\) this is the usual layer order HH, HV, VV, HH.HV*, HH.VV*, HV.VV* of the SanFrancisco150 image.

Usage

as_polsar_array(x)

as_polsar_vec(x)

Arguments

x

A complex array (m x m x n), a single m x m matrix, or an n x p complex matrix (or vector of length p).

Value

as_polsar_array() returns a complex array m x m x n; as_polsar_vec() returns an n x p complex matrix.

Examples

S <- diag(3) + 0i
S[1, 2] <- 0.2 + 0.1i
S[2, 1] <- Conj(S[1, 2])
v <- as_polsar_vec(S)
v
#>      [,1] [,2] [,3]     [,4] [,5] [,6]
#> [1,] 1+0i 1+0i 1+0i 0.2+0.1i 0+0i 0+0i
as_polsar_array(v)[, , 1]
#>          [,1]     [,2] [,3]
#> [1,] 1.0+0.0i 0.2+0.1i 0+0i
#> [2,] 0.2-0.1i 1.0+0.0i 0+0i
#> [3,] 0.0+0.0i 0.0+0.0i 1+0i