Wednesday, January 02, 2008

*New* Elevation Tools

The addition of rTSS to WKO+ required some additional tools and features within the application. Namely, because the calculations for Normalized Graded Pace are heavily dependent upon good elevation data, we needed to provide some facilities for correcting elevation. GPS devices, while getting better, still have difficulty determining the correct elevation in some circumstances. And, if you run on a treadmill, that good old barometric sensor in your watch just isn't going to give you what you want.

To that end, we've added two new correction tools. Both are available on the Edit Corrections menu. And, you can access either by right-clicking on the range name or current selection next to the Graph View.

The first and most exciting is the support for correcting elevation data from GPS devices by using either of two web services. The first retrieves the best known elevation data from the US Geological Service. Folks with TrainingPeaks subscriptions are also given the choice of using TrainingPeaks new "Ground Control" service which is now being updated with the latest information as it becomes available. The advantage of using GroundControl is that it runs very quickly compared with the USGS system.

The second way to either correct your elevation or even add an elevation channel to your workout file is to use the Override Altitude Manually dialog. This tool allows you to set the elevation for any range simply by providing a starting elevation and a % grade.

This example demonstrates how I fix a file after running on the treadmill.

In each picture, the original elevation as reported by the device is depicted in orange. The "fixed" elevation is depicted in yellow.

Neither feature is limited to run workouts and Cyclists may find the features helpful as well.

So, what kind of effect does fixing your elevation have
on rTSS? Well, comparing the rTSS from the first graphic with the corrected graphic, we find that rTSS has changed from 66.4 to 72.9. That's almost a 10% change! So, be sure to take a look at the elevation data coming from your run workouts!