pyacs.sol.helmert module¶
calculates Helmert transformation
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pyacs.sol.helmert.helmert_matrix(x, y, z, tran=True, rot=True, scale=True, equilibrate=True)[source]¶ Generates a Helmert transformation matrix for a single point Can also create translation/rotation/scale transformation matrix
- Parameters
x,y,z – point geocentric coordinates (m)
tran,rot,scale – boolean telling that translation/rotation/scale will be included
equilibrate – (default True) changes the unit of the matrix so that x are in km and scale in mas for better conditionning of the matrix
- Returns H
the transformation matrix as 2D numpy matrix
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pyacs.sol.helmert.observation_equation_helmert_local(xf, yf, zf, xr, yr, zr, tran=True, rot=True, scale=True)[source]¶ Generate the linear transformation equation system for coordinate of a sites in two reference system. The equation system is generated for E,N,U components
- Parameters
xf,yf,zf – geocentric coordinates in the initial reference (also called ‘free’ frame)
xr,yr,zr – geocentric coordinates in the final reference (the reference frame)
tran,rot,scale – boolean telling that translation/rotation/scale will be included
- Return A,B
the design matrix and observation vector
- Note
VCV not accounted yet
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pyacs.sol.helmert.estimate_helmert(H_Gpoint_ref, H_Gpoint_free, vcv_xyz=None, psd=None, tran=True, rot=True, scale=True, lexclude=[], method='Dikin_LS', threshold=5.0, verbose=True)[source]¶ Estimates Helmert or transformation parameters between two sets of coordinates Default is a 7-parameters transformation (translation, rotation & scale)
:param H_Gpoint_ref : dictionary of Geodetic Points (Gpoint instance) used as reference :param H_Gpoint_free: dictionary of Geodetic Points (Gpoint instance) used as free :param psd: psd object from sinex library for post-seismic deformation :param tran,rot,scale: boolean telling if the transformation will use translation/rotation/scale :param method: ‘LS’ (Least-Squares) or ‘Dikin_LS’ (a sequence of L1 and L2 norm) estimation :param threshold: threshold value for outlier rejection (default 5.) :param verbose: boolean