WRONG ARPT APCH.

Narrative

WE WERE ON ARR TO SDF ARRIVING OUT OF THE N; ON A VECTOR OF 180 DEGS DSNDING THROUGH 6000 FT MSL. WE SAW THE ARPT AND ADVISED APCH CTL WE HAD A VISUAL ON THE FIELD. WE WERE TOLD TO 'EXPECT APCH CLRNC IN 4 NM.' AS WE DSNDED THROUGH 5000 FT MSL; THE SUN ANGLE (APPROX 10 DEGS) AND THE HAZE CAUSED US TO LOSE SIGHT OF THE ARPT. WE WERE GIVEN CLRNC FOR A VISUAL APCH AND THE CAPT CONTINUED FLYING TOWARDS THE MARKER; 'LAANG;' FOR THE VISUAL LINEUP TO RWY 29. PRIOR TO ARRIVING AT LAANG; WE BOTH SAW WHAT WE THOUGHT WAS SDF AND THE CAPT BEGAN HIS TURN TO LINE UP ON FINAL APCH AND BEGAN TO CONFIGURE FOR LNDG. IMMEDIATELY AFTER WE WERE ESTABLISHED ON FINAL; WE BOTH XCHKED THE INSTS AND OUR HDG AND REALIZED WE LINED UP ON FINAL AT BOWMAN. WE IMMEDIATELY CALLED SDF TWR AND TOLD THEM WE WERE LINED UP AT THE WRONG ARPT. WE LEVELED OFF AT APPROX 2000 FT MSL AND INITIATED A GAR. SDF TWR ACKNOWLEDGED AND CONFIRMED OUR ERROR AND GAVE US A VECTOR AND TOLD US TO CLB TO 3000 FT MSL. THEY ALSO POINTED OUT TFC THAT WE ALREADY HAD IN SIGHT. WE CROSSED OVERHEAD 1 LIGHT ACFT; APPROX 750-1000 FT ABOVE. THE SUBSEQUENT APCH AND LNDG AT SDF WERE UNEVENTFUL. AS WE TAXIED INTO THE GATE; THE CTLR SAID EVERYONE IN THE PATTERN AT BOWMAN SAW US AND THERE WAS 'NO PROB' AND NO NEED TO CALL THEM.