Trivial cleanup commit, to test continuous integration server.

[flightgear.git] / src / Navaids / navrecord.cxx

diff --git a/src/Navaids/navrecord.cxx b/src/Navaids/navrecord.cxx
index 61b5725a7bc2abaee334fa3801c40be5ff54893c..041c12f1a663fc84aef85f6b021682eedb01c089 100644 (file)
--- a/src/Navaids/navrecord.cxx
+++ b/src/Navaids/navrecord.cxx
@@ -91,6 +91,9 @@ void FGNavRecord::initAirportRelation()
   }
   
   mRunway = getRunwayFromName(_name);  
+  if (!mRunway) {
+    return;
+  }
   
   if (type() != GS) {
     readAirportSceneryData();
@@ -101,7 +104,7 @@ void FGNavRecord::initAirportRelation()
     mPosition.setElevationFt(mRunway->elevation());
   }
   
-  if (type() == ILS) {
+  if (type() == ILS || type() == LOC) {
     mRunway->setILS(this);
   }
   
@@ -135,7 +138,11 @@ void FGNavRecord::readAirportSceneryData()
   SGPropertyNode* runwayNode, *ilsNode;
   for (int i=0; (runwayNode = rootNode->getChild("runway", i)) != NULL; ++i) {
     for (int j=0; (ilsNode = runwayNode->getChild("ils", j)) != NULL; ++j) {
-      if (ilsNode->getStringValue("nav-id") == ident()) {
+      // must match on both nav-ident and runway ident, to support the following:
+      // - runways with multiple distinct ILS installations (KEWD, for example)
+      // - runways where both ends share the same nav ident (LFAT, for example)
+      if ((ilsNode->getStringValue("nav-id") == ident()) &&
+          (ilsNode->getStringValue("rwy") == mRunway->ident())) {
         processSceneryILS(ilsNode);
         return;
       }
@@ -145,7 +152,6 @@ void FGNavRecord::readAirportSceneryData()
 
 void FGNavRecord::processSceneryILS(SGPropertyNode* aILSNode)
 {
-  assert(aILSNode->getStringValue("rwy") == mRunway->ident());
   double hdgDeg = aILSNode->getDoubleValue("hdg-deg"),
     lon = aILSNode->getDoubleValue("lon"),
     lat = aILSNode->getDoubleValue("lat"),
@@ -158,9 +164,7 @@ void FGNavRecord::processSceneryILS(SGPropertyNode* aILSNode)
 void FGNavRecord::alignLocaliserWithRunway(double aThreshold)
 {
 // find the distance from the threshold to the localizer
-  SGGeod runwayThreshold(mRunway->threshold());
-  double dist, az1, az2;
-  SGGeodesy::inverse(mPosition, runwayThreshold, az1, az2, dist);
+  double dist = SGGeodesy::distanceM(mPosition, mRunway->threshold());
 
 // back project that distance along the runway center line
   SGGeod newPos = mRunway->pointOnCenterline(dist);
@@ -169,14 +173,46 @@ void FGNavRecord::alignLocaliserWithRunway(double aThreshold)
   SG_NORMALIZE_RANGE(hdg_diff, -180.0, 180.0);
 
   if ( fabs(hdg_diff) <= aThreshold ) {
-    mPosition = newPos;
+    mPosition = SGGeod::fromGeodFt(newPos, mPosition.getElevationFt());
     set_multiuse( mRunway->headingDeg() );
   } else {
-    SG_LOG(SG_GENERAL, SG_WARN, "localizer:" << ident() << ", aligning with runway " 
+    SG_LOG(SG_GENERAL, SG_DEBUG, "localizer:" << ident() << ", aligning with runway " 
       << mRunway->ident() << " exceeded heading threshold");
   }
 }
 
+double FGNavRecord::localizerWidth() const
+{
+  if (!mRunway) {
+    return 6.0;
+  }
+  
+  SGVec3d thresholdCart(SGVec3d::fromGeod(mRunway->threshold()));
+  double axisLength = dist(cart(), thresholdCart);
+  double landingLength = dist(thresholdCart, SGVec3d::fromGeod(mRunway->end()));
+  
+// Reference: http://dcaa.slv.dk:8000/icaodocs/
+// ICAO standard width at threshold is 210 m = 689 feet = approx 700 feet.
+// ICAO 3.1.1 half course = DDM = 0.0775
+// ICAO 3.1.3.7.1 Sensitivity 0.00145 DDM/m at threshold
+//  implies peg-to-peg of 214 m ... we will stick with 210.
+// ICAO 3.1.3.7.1 "Course sector angle shall not exceed 6 degrees."
+              
+// Very short runway:  less than 1200 m (4000 ft) landing length:
+  if (landingLength < 1200.0) {
+// ICAO fudges localizer sensitivity for very short runways.
+// This produces a non-monotonic sensitivity-versus length relation.
+    axisLength += 1050.0;
+  }
+
+// Example: very short: San Diego   KMYF (Montgomery Field) ILS RWY 28R
+// Example: short:      Tom's River KMJX (Robert J. Miller) ILS RWY 6
+// Example: very long:  Denver      KDEN (Denver)           ILS RWY 16R
+  double raw_width = 210.0 / axisLength * SGD_RADIANS_TO_DEGREES;
+  return raw_width < 6.0? raw_width : 6.0;
+
+}
+
 FGTACANRecord::FGTACANRecord(void) :
     channel(""),
     freq(0)