"Gigantic Jets are much more rare than sprites," says Oscar van der Velde, a member of the Lightning Research Group at the Universitat Politècnica de Catalunya. "While sprites were discovered in 1989 and have since been photographed by the thousands, it was not until 2001-2002 that Gigantic Jets were first recorded from Puerto Rico and Taiwan." Only a few dozen Gigantic Jets have ever been seen, mostly over open ocean.
Amateur astronomers, you can contribute to Gigantic Jet research. Check your local weather radar map for storms just over the horizon, point your meteor cameras in that direction, and click. Gigantic Jets might not be as rare as we think.