St. George Marathon on the course tool

[Paul Petersen]

I've sketched out the St. George Marathon on the course tool. It is pretty rough. The finish line is definitely off, because I had to end it early to get the distance remotely close. So either my start line is off, or the tangents add up. I didn't have the patience to zoom in very close.

Any case, it should still give you decent numbers, and they agree with my "magic spreadsheet" pretty closely. Check it out. If someone can get a better (more accurate) course drawn out, I'll delete this one.

[Sasha Pachev]

Paul:

Thanks for posting this. The direct link to it is here:

http://fastrunningblog.com/course.php?course_id=125

One reason for the distance being longer - looks like the USGS elevation data rounding has put you into a ditch a few times and made you climb out of it. When you enable crazy grade correction and set the maximum possible grade to 7%, the distance reduces from 26.31 to 26.27. The combination of tangent errors, not knowing the exact location of the start and the finish, and possible coordinate drift on the Google maps can very well account for the difference of 0.05 miles.

[Paul Petersen]

I probably put myself in the ditch a few times. Like I said, I was not zoomed in very close. I am actually about a block short of the park, so am at least 0.125 miles from the real finish.

What elevation model are you using? 30m? 10m?

For the future, it would be nice if there was a way to edit vertices in the course tool. I don't know if the google api will let you do that. I know you can do it in Google Earth. But that way we could go back and refine courses with greater detail.

[Cody Draper]

Paul - Could you share your "magic" spreadsheet so we all could use it?   If so what is the link to download it?
Thanks

[Sasha Pachev]

Paul:

I am using whatever USGS has on its servers. I can fix the Course Tool to allow point editing - it is a bit of work, but can be done.

[Kory Wheatley]

Paul, I would also be interested in your spreadsheet.