What channels have stations that were affiliated in 2002?
CREATE TABLE "table1_11147852_1" (
  "city_of_license_market" text,
  "station" text,
  "channel_tv_dt" text,
  "year_of_affiliation" text,
  "owned_since" text
);
SELECT "channel_tv_dt" FROM "table1_11147852_1" WHERE "year_of_affiliation"='2002';