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I believe it can calculate all that because of the data logging feature. Also has been out for awhile, there's even a yahoo discussion group that existed for awhile.
The VBOX monitors these messages, and by measuring the Doppler Shift* in the carrier signals coming from three or more satellites, it calculates the velocity of the receiver.
All GPS receivers work on this principle. 3 Satellites will give 2D navigation and 4 Satellites will give 3D navigation (altitude added). Most civilian GPS receivers (even the low end) already have the capability to do all that this box does. I use a Garman 12 (about $125) as an emergency back up when I fly in case I go down. Its about the size of a cell phone and fits perfectly in my lower leg pocket of my flight suit. I can order a cable and software that will allow me to download info from the receiver into my computer. I can then pick out points from that information on a graph and let the computer figure 0-60, 1/4mile, braking , etc. Not sure after you purchace the cable and software for the Garman, which one will be cheaper, but I'll bet you could get more use out of a hand held GPS over a box that stays in your car. As far as accuracy, Since the government turned off the selective authorization, I have been very pleased with the accuracy. I've even compared mine to a coded military GPS and it was dead on, even with the time.
That's my 50 cents
