The altitudes of the two aircraft are accurately known from GPS data recorded on the video frames. We digitize the TV frames using a True Vision Targa M8 board. The digitized frame is then corrected for lens distortion and for pincushion and off axis distortions introduced by the SIT camera. By use of Stereo we can triangulate on any feature visible from both aircraft. The palpable front ends of the blue jets lose brightness and contrast with respect to the background as they propagate to altitudes above about 30 km, but we can reasonably triangulate the position of the front to about 40 km altitude.
Some information is lost in the digitization process.
When the jets are observed in real time using the original video tapes the jets can be observed well above 40 km. We have triangulated the position vs. time of six separate blue jets. There will be further detailed calibrated analysis of color ratios. Blue jets may be rarer than the sprites, which are essentially a D region event also associated with mesoscale thunderstorms. The color is mostly blue with some green.