This page will generate an IAC 1000 meter aerobatic box, at a location you choose, that can be opened in Google Earth. The code creates acroBox.kml, which you save to your local file system and then open with Google Earth.
The purpose of creating the 3d box in Google Earth is so you can load your GPS track from a practice flight and see how well you did staying in the box. See this page for one method of adding a GPS track to the acro box.
The default values in the form are for the acro box used by IAC 35 at the Green Mountain Aerobatic contest in Springfield Vt.
Enter Latitude and Longitude in decimal degrees. Enter west longitude and south latitude as negative numbers.
If you want the floor of the box to be higher, then make the ground altitude higher. The ground box markers will always be clamped to the earth floor, but setting an altitude higher than ground-level will adjust the altitude of the box floor. Also, The code doesn't know the ground elevation of your box, so if you don't use the correct ground elevation, your box may be created below sea level.
Known issues: creating the kml file on an iPad doesn't work. The lat/longs will be incorrect and the box will appear on the equator. You can still view the box on an iPad, but first you have to create it on a pc, mac or android device and then save the file to the iPad. I haven't tried an iPhone yet
Credit: This web site has a good description of the math used to calculate the corners of the box.
If you have questions, suggestions or better ideas, please email me at firstname.lastname@example.org