}
}
+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)