Index: trunk/BNC/src/PPP/pppParlist.cpp
===================================================================
--- trunk/BNC/src/PPP/pppParlist.cpp	(revision 9446)
+++ trunk/BNC/src/PPP/pppParlist.cpp	(revision 9447)
@@ -396,4 +396,16 @@
     }
 
+    else if (par->type() == t_pppParam::ion) {
+      if (OPT->_obsModelType == OPT->DCMcodeBias ||  OPT->_obsModelType == OPT->DCMphaseBias) {
+        if (par->lastObsTime().valid() && (epoTime - par->lastObsTime() > 1.0)) {
+            remove = true;
+        }
+      }
+      else {
+        if (par->lastObsTime().valid() && (epoTime - par->lastObsTime() > 60.0)) {
+            remove = true;
+        }
+      }
+    }
     if (remove) {
       delete par;