%                              vecefp90.m
%  Scope:   This MATLAB macro performs the transformation from ECEF WGS-84 to 
%           PZ-90 ("Parametri Zemli 1990", i.e. earth's parameters 1990) frame
%           coordinates for a given position vector with components expressed 
%           in meters.
%  Usage:   ppz90 = vecefp90(pecef)
%  Description of parameters:
%           pecef  -  input, ECEF (WGS-84) position vector with components in 
%                     meters
%           ppz90  -  output, PZ-90 frame position vector, with components in 
%                     meters
%  Reference:
%           [1] Misra, P. N., Abbott, R. I., Gaposchkin, E. M., Integrated use
%               of GPS and GLONASS: Transformation between WGS84 and  PZ-90. 
%               Proceedings of the 9th International Technical Meeting of the 
%               Satellite Division of the Institute of Navigation, ION GPS-96, 
%               Kansas City, September 16-20, 1996, pp. 307-314. 
%  Last update:  04/04/00
%  Copyright (C) 1997-00 by LL Consulting. All Rights Reserved.

function   ppz90 = vecefp90(pecef)

rotangle = 1.9e-6;       %  rotation angle in radians
d = 2.5;                 %  translation distance in meters

ppz90 = zeros(3,1);
ppz90(1) = pecef(1) + pecef(2) * rotangle;
ppz90(2) = - pecef(1) * rotangle + pecef(2) - 2.5;
ppz90(3) = pecef(3);