Sorry for posting all this again, I hope I don't bore to death some members of this site...
I've done the same Machin says, but for Catalunya. The files include all radii, straight length and differentiates between spiral transition curves and circular segments.
Catalunya AutoCAD drawing Zip file, 76Kb
Catalunya AutoCAD drawing with photographs Zip file, 1.5 Mb (you have to extract the jpg images included to the same directory where you extract the dwg file).
I found a difference between the length calculated in AutoCAD and the length measured with theodolite of only 7 meters in a total lenght of 4.734 m. That's an error of less than 0.1%.
The zip files above include a simple Excel file with info about Gs, taking the info of Brembo about braking zones and my calculations of radii. It can serve you as an example or first approximation.
To achieve this
impressive result,
I have a couple of recommendations in my personal website (it's a little complicated, unless you're familiar with GIS software. I
might find the time to help you, if you cannot get satisfactory results):
Restitution of tracks using satellite photos
In short, if you draw a line in Google Earth, you can extract the coordinates of the points you've drawn from the KML file Google produces. You can convert these coordinates from geographic coordinates (degrees, minutes, seconds) to planar coordinates (meters) using ArcGis or some other software. So, you get the exact positions of the reference points you've drawn in Google Earth. Then you can locate with precision the pictures in AutoCAD (instead of stretching until you find a match, visually, as machin explains). This process is called "
orthorectification".
You can also simply take the coordinates (in meters) of some points you put by hand on top of the picture and draw them in AutoCAD (entering the coordinates to draw them). These points serve you as references to "stretch" the image until the points drawn in GEarth match the points drawn in AutoCAD.
I strongly recommend to print the Google Earth image to the MID printer in Windows (the one named Microsoft Office Document Image Writer), using the largest size you can (configure the printer, use personal size, 90 cm long, I think). You produce a MID file. Export it to TIFF using the MID image software that will open after you "print" the image. This way you get 5.000 pixels pictures. To "do" Catalunya, I "took" three pictures (I think) that you can see in the file linked above.
This is a snapshot of the end product (before the last modifications to the track):
Just in case, I have build over the years a file with the location of over 700 tracks in Google Earth that you might find useful. It includes
all F1 tracks ever, IRL and NASCAR tracks for last year and over 600 other tracks. It also has the location of some F1 factories and testing tracks:
Ciro's Circuits
In many of the tracks (I think all F1 tracks, at least) I've included a "lap around the circuit" line (that you can use to find the "reference points" I mentioned before).
If you choose to take a "virtual lap", change the angle of the camera and the distance, and use the "play" button at the bottom of the Google Earth list, to the left of the GEarth screen. Here you have the instructions:
Instructions to view "my" tracks
You can find a link to my site at most of the articles on F1 tracks in Wikipedia.
Finally, I use a PC and an old Brembo card, as machin does, to set up my old (also) kart. It works wonders, if you want to scare the competition...