Last Updated: March 26, 2003
This page provides additional information regarding the use and operation of the WebReplay system. Select from one of the categories below, or just scroll through the entire page.
Select the start date by clicking on a day on the calendar. Navigate through the months with the 'back' and 'forward' triangles to the left and right of the month name, respectively. If either of these triangles change to a lighter color, then there is no flight track information for previous or subsequent months, and that triangle cannot be selected. Likewise, if a date changes to a lighter color, then there is no flight track information for that day, and that day cannot be selected.
NOTE: Once a date is selected, a request is made to the database server to acquire the hourly flight operation counts for that day (see 'Selecting the time' below). Repeated, rapid selection of different dates may cause unreasonable delays on this web page. After selecting a date, wait for one or two seconds for the hour bar-graph to update.
Just below the calendar is an hour bar-graph showing how many flight operations occurred during each hour on the selected date. The bar graph is seperated into three sections - Day, Evening and Night - from left to right. Click on one of the bars on the bar graph to select an hour.
Just to the right of the calendar is a minute slider which you can use to select how many minutes past the hour to start the replay. Click anywhere on the slider, or drag the slider handle with the mouse.
Once the start date and time have been selected, click the VCR-like Play button below the map to the left. Flight tracks will begin animation from the selected date and time and continue for a duration of 30 minutes. Map views may be changed by zooming and scrolling during replay.
While flight tracks are animating, click the Pause button (to the left of Play) to suspend replay. Map views may be changed by zooming and scrolling while paused. Click the Play button again to resume replay.
Click on the Stop button (to the left of Pause) to stop replay. All animated flight tracks will be removed from the display. A new start date and time can be selected while stopped.
The maps used on this web site are in format referred to as Scalable Vector Graphics (or SVG). The processing power of your computer is used to transform this SVG formatted map into a format that can be displayed on the Flight Replay web page. If your computer is an older, slower model, or if you have other applications running (which consume some or all of your computer's resources), map rendering and display performance may be affected. Please close down all other applications if you experience performance problems with this web page.
There are ten zoom levels provided in order to view a particular map area in greater detail. Zoom Level 1 is an overview of the Bay Area while Zoom Level 10 represents neighborhood views. Street names begin to appear at Zoom Level 8.
A variety of maps are available in order to support different detail at varying zoom levels. When zooming in or out, a different map may be requested from the server. While the map is loading, a message "loading map ..." will appear in the status bar at the bottom of the Flight Replay window. The map area might also change to white during this time. Depending on the speed of your Internet connection (56K, DSL, T1, ...) and the processing power of your browser-enabled computer, this can take anywhere from 5 to 15 seconds. Please be patient while a map is loading and wait to perform any other action in the Flight Replay window until the new map and view are displayed.
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