You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 

48 lines
1.7 KiB

function xERot = FlightTimeCorrection(xE, dTflightSeconds)
%xERot = FlightTimeCorrection(xE, dtflight);
% Compute rotated satellite ECEF coordinates caused by Earth
% rotation during signal flight time
%
% Inputs:
% xE - satellite ECEF position at time of transmission
% dtflight - signal flight time (seconds)
%
% Outputs:
% XeRot - rotated satelite position vector (ECEF at trx)
%
% Reference:
% IS GPS 200, 20.3.3.4.3.3.2 Earth-Centered, Inertial (ECI) Coordinate System
%Author: Frank van Diggelen
%Open Source code for processing Android GNSS Measurements
%See also "A software receiver for GPS and Galileo", K. Borre at al.
%Rotation angle (radians):
theta = GpsConstants.WE * dTflightSeconds;
%Apply rotation from IS GPS 200-E, 20.3.3.4.3.3.2
%Note: IS GPS 200-E shows the rotation from ecef to eci
% so our rotation R3, is in the opposite direction:
R3 = [ cos(theta) sin(theta) 0;
-sin(theta) cos(theta) 0;
0 0 1];
xERot = (R3*xE(:))';
end %end of function FlightTimeCorrection
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Copyright 2016 Google Inc.
%
% Licensed under the Apache License, Version 2.0 (the "License");
% you may not use this file except in compliance with the License.
% You may obtain a copy of the License at
%
%     http://www.apache.org/licenses/LICENSE-2.0
%
% Unless required by applicable law or agreed to in writing, software
% distributed under the License is distributed on an "AS IS" BASIS,
% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
% See the License for the specific language governing permissions and
% limitations under the License.