function [gdop,pdop,tdop] = ...	cpdops1 (xsat,ysat,zsat,station);%CPDOPS: Compute the different existing DOP's%% The function computes the different existing DOP'values, including% GDOP, PDOP, TDOP, HDOP, FDOP, LDOP and VDOP as a function of time.%% Syntax:% [gdop,pdop,tdop,hdop,fdop,ldop,vdop] = cpdops ...%    (tsat,xsat,ysat,zsat,station,elev,cutoff,rotmat);%% Input arguments:%    tsat    - Times (in seconds into the current GPSWEEK)%    xsat    - X-positions of satellites (WGS'84, Earth-fixed)%    ysat    - Y-positions of satellites (WGS'84, Earth-fixed)%    zsat    - Z-positions of satellites (WGS'84, Earth-fixed)%    station - Station coordinates (WGS'84, Earth-fixed)%    elev    - Elevation of each satellite on eah time in tsat%    cutoff  - Cutoff-elevation%    rotmat  - Rotation-matrix from WGS'84/XYZ to WGS'84/PLH%% Output arguments:%    gdop    - Geometrical Dilution of Precision%    pdop    - Positional  Dilution of Precision%    tdop    - Time Dilution of Precision%    hdop    - Horizontal Dilution of Precision%    fdop    - Lattitude Dilution of Precision%    ldop    - Longitude Dilution of Precision%    vdop    - Vertical Dilution of Precision%% ----------------------------------------------------------------------% File.....: pldops.m% Date.....: 12-OCT-2000% Version..: 1.0% Author...: Peter Joosten%            Mathematical Geodesy and Positioning%            Delft University of Technology% ----------------------------------------------------------------------% ---------------------% --- Compute DOP's ---% ---------------------for i = 1:length(tsat);    [amat] = Amatrix (xsat,ysat,zsat,station,m);
    if m >= 4;        qx      = inv(amat' * amat);        gdop(i) = sqrt(trace(qx));    pdop(i) = sqrt(trace(qx(1:3,1:3)));    tdop(i) = sqrt(qx(4,4));
      end;  end;