North American Animated Flight Atlas

Transcription

1 Journal of Maps, 2007, North American Animated Flight Atlas MICHAEL P. PETERSON 1 and JOCHEN WENDEL 2 1 Department of Geography / Geology, University of Nebraska at Omaha, Omaha, NE 68106, USA; mpeterson@unomaha.edu 2 Illingen, GERMANY; (Received 5 th September 2006; Accepted 10 th October 2006) Abstract: There are many different landscapes. The landscape mapped here forms in the sky as thousands of aircraft are carefully choreographed by ground control to ferry passengers from one place to another. It is this landscape of constantly moving air traffic that is the subject of a new atlas. The maps in the North American Animated Flight Atlas are animations depicting flight traffic over North America. All animations depict traffic over 24-hour periods. Over 70 animations are presented on a DVD depicting flight traffic by airline, airplane, airport, and route. The minute-by-minute location of airplanes was mapped using a program called FlyteTrax from FlyteComm, Inc. The program updates the position of flights in real time and also allows the filtering of flights based on the aircraft, airline, and the departure or arrival airport. At 1440 frames each (the number of minutes in a day), over 100,000 individual maps were used to create the animations. Animation files are between 5 MB and 66 MB in size for a total of about 1.6 GB. The animations present a landscape of flight traffic that is made visible through the atlas for the first time. This article examines the construction of the animations, some of the resultant patterns, and presents a single animation depicting all inbound and outbound commercial traffic for Hartsfield-Jackson Atlanta International airport. ISSN

2 1. Introduction According the Statistical Abstract of the United States (2003), there are over 9 million aircraft departures every year carrying 612 million paying passengers. This is nearly twice the population of the US and Canada combined. Over 600,000 people are employed in the air transportation industry. Air traffic is obviously a major aspect of the economy and people s lives and yet we have little understanding of how complex air traffic has become. To better understand air traffic in North America, an atlas on DVD was created consisting of over 70 animations depicting different types of flight traffic over North America. All animations show traffic for 24-hour periods and were acquired between March 2003 to September of The individual frames for the animations were made using a program called FlyteTrax 2002 from FlyteComm, Inc. (FlyteComm 2002), and were subsequently processed and assembled into animations. The tracking of flights over North America is based on a combination of flight plan and radar tracking data that are collected by over 20 US and Canadian Air Route Traffic Control Centers (ARTCCs). These data are transmitted in real-time via geostationary satellite link to the Transportation Systems Center (TSC) in Cambridge, Mass. A computer system at the TSC merges these data into a single coherent data stream, which is then redistributed by satellite to the Air Traffic Control System Command Center ( central flow control ) at the headquarters of the Federal Aviation Administration in Herndon, Virginia (see Figure 1), as well as to the Traffic Management Units at each of the ARTCCs, and to a handful of companies that make the data available to private subscribers and to the public. 99

3 Figure 1 The Air Traffic Control System Command Center in Herndon, Virginia, USA. (From FlyteTrax, a product of FlyteComm, Inc., is a Windows computer program for flight mapping that dynamically updates the position of flights based on data made available through the FAA. On start-up, the program connects to the FlyteComm server through the Internet and receives the current database of air traffic activity. Once the initial database is downloaded, aircraft movement messages are directed through the Internet to the FlyteTrax program every minute to update the position of flights. The actual data are delayed by five minutes for security reasons. The program can overlay air traffic with a wide selection of maps such as geo-political boundaries, air traffic control center boundaries, high altitude jet routes, satellite cloud and radar imagery. Figure 2 depicts a map of commercial air traffic for a typical weekday at 11:59 AM. This article reviews the making of the North American Animated Flight Atlas (Peterson and Wendel 2006). 100

4 Figure 2 All commercial aviation for the 48 US states and southern Canada at 11:59 AM Central time on a weekday. At this moment, 4230 commercial flights are being tracked by air traffic control. Hubs are clearly visible for Dallas/Ft. Worth, Atlanta, Chicago, Minneapolis, Denver, Phoenix, Los Angeles, and Las Vegas. 2. Methods The individual frames for the animations were captured with the FlyteTrax program at one minute intervals to correspond with how often the program updates the location of aircraft. In addition to the location of each flight, other attributes are available from the data tag provided by the aircraft s transponder. The data tag includes eight separate fields: 1) flight ID; 2) airline; 3) altitude; 4) aircraft type; 5) ground speed; 6) estimated time of arrival; 7) departure airport; and 8) arrival airport. Animations were based on some combination of the airline, aircraft, and airport codes. The FlyteTrax program displays maps using two different map projections, Mercator and the Lambert Conformal Conic. A decision was made to use the latter projection as the conic projection conforms more to most people s conception of the shape of the area. When a selection of flights is made using the FlyteTrax s filtering option, the program shows each flight as a small aircraft symbol. Figure 3 displays 101

5 a single frame of the animation for Minneapolis/St. Paul (MSP) including all inbound and outbound commercial flights. Airplane symbols are assigned a random color to indicate the airline. The Minneapolis/St. Paul airport is a hub for Northwest Airlines and the traffic at this airport is dominated by this airline. The current time is super-imposed in the lower-left. The time for all of the animations is provided for the Central Time Zone. One of the airplane symbols over Canada is hollow indicating that a radar position report for this airplane has not been received for at least seven minutes. Intermittent radar contact occurs very occasionally, particularly around the borders of the North American air traffic control system. Figure 3 A single frame of the Minneapolis/St. Paul (MSP) animation. 102

6 In testing the initial animation, it was observed that the time in the lower right corner was difficult to read at animation display speeds. To solve this problem, an analog clock face was added to each frame. This was done automatically by scripting the location of the hour and minute hands in the movie editing program. Frames were also rearranged so that all animations would begin and end at 12 noon. After the individual frames were edited, the 1440 frames were brought into a movie-editing program to create the animation for one 24-hour period. The individual frames, saved as JPEG images, would total between 500 and 600 MB in size. The initial animations that were created using standard compression techniques were nearly 200 MB. Although files of this size can be stored and managed with commonly-used computer systems, these systems cannot move such vast amounts data to the screen fast enough to create an acceptable animation. Through further testing, it was determined that an acceptable compression scheme was DivX (or the open source Xvid), a video compression format that is available from The DivX codec was combined with the avi file format that is in common use for video files distributed through the Internet. With this compression scheme and file format, file sizes were reduced to between 5 MB to 66 MB - depending upon the complexity of the individual images. The DivX codec works with both Windows Media Player and the QuickTime player and is installed after the player application. If both players are installed, the animations will open in whichever application is set to deal with.avi files. Windows Media Player (Microsoft, Inc.) and QuickTime Player (Apple, Inc.) are free applications and are included with the operating system or can be downloaded from their respective websites. Although either player has versions on the alternate operating system, it seems best to use Media Player on Windows and QuickTime when using a Macintosh. Each animation file can be played at three different speeds. The first speed, designated as SLOW, shows the 24-hour day in 1 minute and 36 seconds, corresponding with an effective time-lapse ratio of 1:900 (15 minutes are shown in one second). The NORMAL animation depicts the 24 hour period in 48 seconds for a ratio of 1:1,800 (30 minutes are shown in 1 second). A third FAST animation shows the 24 hour day in 24 seconds for a time lapse ratio of 1:3,600 (60 minutes are shown in one second). A single animation showing commercial traffic for Hartshorne-Jackson 103

7 Journal of Maps, 2007, Peterson, M.P. & Wendel, J. Atlanta International airport is included in Figure 4. Within the atlas, each animation is placed with a page as shown in Figure 4 that includes a caption. Atlanta is the busiest airport in the world in terms of passenger traffic. The animation shows the hub-spoke pattern that is visible on a number of the animations. The entire atlas with 70 animations and a 46-page booklet is available from the Cartography and GIS Laboratory at the University of Nebraska at Omaha. The 70 animations show traffic at all major cities by major aircraft types, major corridors and regions. In addition, two animations show the diversion of aircraft due to the advance of Hurricane Katrina. More information about the atlas is available from the atlas web page at Figure 4 A single page from the North American Animated Flight Atlas showing all inbound and outbound air traffic for Hartshorne-Jackson Atlanta International airport. To view this animation, first download and install the Divx ( or Xvid ( codecs. After the codec has been installed, click on the map above. Adobe Reader will play the animation in whatever application is set to open.avi files. See for more detailed instructions. 104

8 3. Conclusion Movement is an important part of the world but is rarely shown in maps. The animations in this atlas of flight traffic represent an attempt to make visible what happens in the sky on a daily basis. They depict how traffic varies throughout the day in both intensity and direction of flights. They show the pulsating traffic at the major hubs as the arrival and departure of smaller commuter aircraft are timed with incoming and outgoing larger aircraft. They show the differences between passenger flights and flights for express mail delivery that dominate the sky during the nighttime hours. In short, the animations depict patterns that would not be visible unless viewed in this form. Software Three main commercial programs were used to make the animations: FlyteTrax, Capture Eze Pro, and Adobe Premiere. FlyteTrax was used to map the minute by minute locations of flights. Capture Eze Pro saved the screen images to disk. Adobe Premiere was used both to add the clock face and assemble the frames into the animations. In addition to these programs, a utility program was used to rename the files for proper sequencing and Macromedia Director was used to create the interface to the animations on the DVD. Acknowledgements The authors would like to thank FlyteComm, Inc. of Mountain View, California, for use of their FlyteTrax program. The authors would especially like to thank Product Support Specialist James Bunker who provided a considerable amount of support during the entire process. This atlas would not have been possible without the help of Mr. Bunker or FlyteComm. 105

9 References FLYTECOMM, INC. (2002) FlyteTrax FlyteComm, Inc., Mountain View, CA. PETERSON, M. P. and WENDEL, J. (2006) Animated Atlas of Air Traffic over North America. Cartography and GIS Laboratory, University of Nebraska at Omaha, Omaha, NE. U.S. CENSUS BUREAU (2003) Statistical Abstract of the United States [online]. Available from: [Accessed: 3rd February 2006]. 106