+ // Query the database for the specified frequency. It is assumed
+ // that there will be multiple stations with matching frequencies
+ // so a position must be specified. Lon and lat are in degrees,
+ // elev is in meters.
+ FGNavRecord *findByLoc( double lon, double lat, double elev );
+
+ // locate closest item in the DB matching the requested ident
+ FGNavRecord *findByIdent( const char* ident, const double lon, const double lat );
+
+ // Given an Ident and optional freqency, return the first matching
+ // station.
+ FGNavRecord *findByIdentAndFreq( const char* ident,
+ const double freq = 0.0 );
+
+ // returns the closest entry to the give lon/lat/elev
+ FGNavRecord *findClosest( double lon_rad, double lat_rad, double elev_m );
+
+ inline nav_map_type get_navaids() const { return navaids; }
+};