Changeset 11099 in ntrip for trunk/BNC/src/combination/bnccomb.cpp

Timestamp:

Oct 19, 2026, 10:30:14 AM (5 hours ago)

Author:

stuerze

Message:

Combination: further improvements

File:

• trunk/BNC/src/combination/bnccomb.cpp (modified) (5 diffs)

trunk/BNC/src/combination/bnccomb.cpp

@@ -34 +34 @@
 
 const double sig0_offACSat = 1000.0;
-const double sigP_offACSat =   0.01;
+const double sigP_offACSat =   0.01; // per REF_SAMPL_offACSat, scaled with the time between the epochs
+const double REF_SAMPL_offACSat = 10.0; // [s]
 
 const double sig0_clkSat   =  100.0;
@@ -1183 +1184 @@
   // Prediction Step
   // ---------------
+  // The random walk of the AC satellite offsets is defined per time, not per
+  // epoch (sigP_offACSat per REF_SAMPL_offACSat seconds), so that the result
+  // does not depend on the combination sampling interval
+  double dt = _lastFilterEpoch[sys].valid() ? epoTime - _lastFilterEpoch[sys] : double(_cmbSampl);
+  if (dt <= 0.0) {
+    dt = double(_cmbSampl);
+  }
+  _lastFilterEpoch[sys] = epoTime;
   int nPar = _params[sys].size();
   ColumnVector x0(nPar);
@@ -1194 +1203 @@
     }
     else {
-      _QQ[sys](iPar,iPar) += pp->sigP * pp->sigP;
+      double fac = (pp->type == cmbParam::offACSat) ? dt / REF_SAMPL_offACSat : 1.0;
+      _QQ[sys](iPar,iPar) += pp->sigP * pp->sigP * fac;
     }
     x0(iPar) = pp->xx;
@@ -1349 +1359 @@
     double slope     = (sxx > 0.0) ? sxy / sxx : 0.0;
     double corrCoeff = (sxx > 0.0 && syy > 0.0) ? sxy / sqrt(sxx * syy) : 0.0;
+    // Hysteresis: a flagged AC is used for the clock datum again only after
+    // REINCLUDE_CHECKS passing checks in a row (1 hour). Right after the
+    // exclusion the offsets are reset and not yet converged, so a single
+    // passing check does not prove consistency; a borderline AC would
+    // otherwise change the clock datum every few minutes.
+    const int REINCLUDE_CHECKS = 12;
     if (spread < MIN_SPREAD || slope < MIN_SLOPE || corrCoeff < MIN_CORR) {
+      if (_biasInconsistent.contains(key) && ++_biasConsistentChecks[key] < REINCLUDE_CHECKS) {
+        continue;
+      }
+      _biasConsistentChecks.remove(key);
       if (_biasInconsistent.remove(key)) {
         QString msg = QString("%1 %2 code biases consistent with its clocks again, "
@@ -1372 +1392 @@
                   .arg(acName).arg(sys).arg(refSig).arg(nn)
                   .arg(spread, 0, 'f', 3).arg(slope, 0, 'f', 2).arg(corrCoeff, 0, 'f', 2);
+    _biasConsistentChecks[key] = 0;
     if (!_biasInconsistent.contains(key)) {
       _biasInconsistent.insert(key);