declip: Declip the GPR signal

In emanuelhuber/RGPR: Ground-penetrating radar (GPR) data visualisation, processing and delineation

Declip the GPR signal

Description

Use constrained least squares. Based on the code of Ivan Selesnick: "we minimize the energy of the the third derivative. This encourages the filled in data to have the form of a parabola (second order polynomial), because the third derivative of a parabola is zero.". A constraint on the declipped data range was added (i.e., constrained least squares) like in http://www.cs.cmu.edu/~robust/Papers/HarvillaStern15a.pdf

Usage

declip(x, xclip = NULL, xrange = NULL, lambda = 1, mu = 0)

## S4 method for signature 'GPR'
declip(x, xclip = NULL, xrange = NULL, lambda = 1, mu = 0)

Arguments

x	[GPR]
xclip	[matrix(m,n)] The clipped values, a matrix with the Same dimension as x, with 1 for the positively clipped values, -1 for the negatively clipped values and 0 everywhere else. If xclip = NULL, the clipped values are estimated with the function clippedValues.
xrange	[numeric(2)] the desired range of the declipped values (for the negatively and positively clipped values) used as a constraint whose strength depends on the value of lambda. If xrange = NULL, the desired range is set equal to the clipped data range +/- 10%.
lambda	[numeric(1)] Positive value that add some noise to stabilize the matrix inversion used in the least-square approach (could be useful if the matrix to invert is singular, use small value, e.g., 0.00001 of the signal amplitude).

Value

[GPR]

emanuelhuber/RGPR documentation built on March 18, 2024, 8 p.m.