Index: trunk/BNC/src/RTCM3/RTCM3coDecoder.cpp
===================================================================
--- trunk/BNC/src/RTCM3/RTCM3coDecoder.cpp	(revision 11040)
+++ trunk/BNC/src/RTCM3/RTCM3coDecoder.cpp	(revision 11041)
@@ -702,5 +702,8 @@
           }
           t_frqAntenna frqAntenna;
-          frqAntenna._freqIndex                = f;
+          frqAntenna._frqType = _ssrCorr->antFreqIndexToStr(si.sysChar, f);
+          if (frqAntenna._frqType.empty()) {
+            continue; // reserved/unmapped DF+018 bit position
+          }
           frqAntenna._nadirCorrectionIndicator = satPart.Freq[f].NadirCorrectionIndicator;
           frqAntenna._nadirCorrection          = satPart.Freq[f].NadirCorrection;