Digital images were acquired from a forward-facing cockpit camera. The field of view is 67 degrees horizontal by 53 degrees vertical. Raw image resolution is 704 (horizontal) x 480 (vertical) rectangular pixels. Pixel height is 1.1 times the pixel width. When displayed on a computer monitor a square will appear as a rectangle with an aspect ratio of 1.1.
The images were acquired at 1 frame per second. They are stored as compressed JPEG files, typically 25kB each. The file name is in the form "c130__fwd_yymmdd_hhmmss.jpg" where "c130" is the platform, "fwd" indicates the forward viewing direction, yymmdd is the 2-digit year, month, and day, and hhmmss is the UTC hours, minutes, and seconds. Each image is annotated at the top left with the date and time as reported to the camera by the aircraft ntp server. The images are stored in tar files covering a one-hour period. The tar files are about 100 MB in size. Occasionally the very beginning or end of a flight may be missing. There may be occasional few second gaps due to network congestion.
Movie files
The flight movies are made from the one frame per second images but they play back at 15 frames per second. Therefore an entire 10 hour flight is viewable as a 40 minute movie. Playback software often has options for varying the playback speed as well as single-frame step capability, forward and backward. The aircraft position, attitude, and a number of state parameters are included as a sidebar in the movie.
To create the MPEG-4 movie files the raw images were scaled to create square pixels appropriate for computer display and the netCDF data was added to the side to give a standard movie resolution of 720 x 480. These processed image files were then compiled into a movie using the linux FFMPEG tools. The movie file for a flight is about 250 MB in size. They can be played by a variety of players, but note that Microsoft Windows Media Player does not yet have MPEG-4 compatibility. Players are available at no charge from the following websites. Versions released prior to January 2006 have not been tested.
Quicktime Mac, Win www.apple.com xine Linux http://xinehq.de mplayer Linux, Mac, Win http://www.mplayerhq.hu/homepage/design6/info.html VLC Linux, Mac, Win http://www.videolan.org/vlcFlight specific comments