Index: trunk/BNC/src/combination/bnccomb.cpp
===================================================================
--- trunk/BNC/src/combination/bnccomb.cpp	(revision 10764)
+++ trunk/BNC/src/combination/bnccomb.cpp	(revision 10770)
@@ -1310,6 +1310,7 @@
     double dC_att = corr->_diffYaw / (2 * M_PI);
     dC_att *= corr->_lambdaIF;
-
-    ll(iObs) = (corr->_clkCorr._dClk * t_CST::c - corr->_satCodeBiasIF - dC_orb - dC_att) - DotProduct(AA.Row(iObs), x0);
+    double dC_apriori_corr =  dC_orb + dC_att;
+
+    ll(iObs) = ((corr->_clkCorr._dClk * t_CST::c) + dC_apriori_corr - corr->_satCodeBiasIF) - DotProduct(AA.Row(iObs), x0);
 
     PP(iObs, iObs) *= 1.0 / (corr->_weightFactor * corr->_weightFactor);