|
|
function [gnssMeas]= ProcessAdr(gnssMeas) |
|
|
% [gnssMeas]= ProcessAdr(gnssMeas) |
|
|
% process the Accumulated Delta Ranges obtained from ProcessGnssMeas |
|
|
% |
|
|
%gnssMeas.FctSeconds = Nx1 vector. Rx time tag of measurements. |
|
|
% .ClkDCount = Nx1 vector. Hw clock discontinuity count |
|
|
% .Svid = 1xM vector of all svIds found in gnssRaw. |
|
|
% ... |
|
|
% .PrM = NxM pseudoranges, row i corresponds to FctSeconds(i) |
|
|
% .DelPrM = NxM change in pr while clock continuous |
|
|
% .AdrM = NxM accumulated delta range (= -k*carrier phase) |
|
|
% ... |
|
|
% |
|
|
% output: |
|
|
% gnssMeas.DelPrMinusAdrM = NxM DelPrM - AdrM, re-initialized to zero at each |
|
|
% discontinuity or reset of DelPrM or AdrM |
|
|
|
|
|
%Author: Frank van Diggelen |
|
|
%Open Source code for processing Android GNSS Measurements |
|
|
|
|
|
if ~any(any(isfinite(gnssMeas.AdrM) & gnssMeas.AdrM~=0)) |
|
|
%Nothing in AdrM but NaNs and zeros |
|
|
fprintf(' No ADR recorded\n'), return |
|
|
end |
|
|
|
|
|
M = length(gnssMeas.Svid); |
|
|
N = length(gnssMeas.FctSeconds); |
|
|
DelPrMinusAdrM = zeros(N,M)+NaN; |
|
|
for j=1:M %loop over Svid |
|
|
AdrM = gnssMeas.AdrM(:,j); %make local variables for readability |
|
|
DelPrM = gnssMeas.DelPrM(:,j); |
|
|
AdrState = gnssMeas.AdrState(:,j); |
|
|
%From gps.h: |
|
|
%/* However, it is expected that the data is only accurate when: |
|
|
% * 'accumulated delta range state' == GPS_ADR_STATE_VALID. |
|
|
%*/ |
|
|
% #define GPS_ADR_STATE_UNKNOWN 0 |
|
|
% #define GPS_ADR_STATE_VALID (1<<0) |
|
|
% #define GPS_ADR_STATE_RESET (1<<1) |
|
|
% #define GPS_ADR_STATE_CYCLE_SLIP (1<<2) |
|
|
|
|
|
%keep valid values of AdrM only |
|
|
iValid = bitand(AdrState,2^0); |
|
|
iReset = bitand(AdrState,2^1); |
|
|
AdrM(~iValid) = NaN; |
|
|
|
|
|
%% work out DelPrM - AdrM since last discontinuity, plot DelPrM-AdrM |
|
|
|
|
|
DelPrM0 = NaN; %to store initial offset from AdrM |
|
|
for i=1:N %loop over time |
|
|
if isfinite(AdrM(i)) && (AdrM(i)~=0) && isfinite(DelPrM(i)) && ... |
|
|
~iReset(i) |
|
|
%reinitialize after NaNs or AdrM zero or AdrState reset |
|
|
if isnan(DelPrM0) |
|
|
DelPrM0 = DelPrM(i) - AdrM(i); |
|
|
end |
|
|
else %reset at NaNs or AdrM zero |
|
|
DelPrM0 = NaN; |
|
|
end |
|
|
DelPrMinusAdrM(i,j) = DelPrM(i) - DelPrM0 - AdrM(i); |
|
|
end |
|
|
end |
|
|
|
|
|
gnssMeas.DelPrMinusAdrM = DelPrMinusAdrM; |
|
|
|
|
|
end %end of function ProcessAdr |
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
|
|
|
|
|
% 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.
|
|
|
|
