Guidance on adding attributes to KML

Question

I can plot a path in KML no problems. Now I need to annotate the vertices with speed and heading. I could handle this as a progression of placemarks, but before I proceed I thought it best to see what others do in this scenario.

As it happens I'm using SharpKML in C#, but that's incidental to the question of approach.

So, recommendations?

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Well, that looks to be it. Placemarks, and possibly gx:Track if you don't mind vendor extensions.

I'm not sure you can annotate individual points in a gx:Track, I haven't tried. Despite this, Jason gets the points for submitting the only answer.

Answer 1

You should consider using the gx:Track as the geometry for your paths in which the speed and elevation can be shown in the Elevation profile.

A good example can be found in this article: http://google-latlong.blogspot.com/2010/06/relive-your-hiking-biking-and-other.html

For each vertex you have a time-location pair with a when for the time and gx:coord for the location. You can also add custom metadata at each time-location pair using an ExtendedData element with gx:SimpleArrayData. See track example with ExtendedData.

          <gx:SimpleArrayData name="cadence">
            <gx:value>86</gx:value>
            <gx:value>103</gx:value>
            <gx:value>108</gx:value>
            <gx:value>113</gx:value>
            <gx:value>113</gx:value>
            <gx:value>113</gx:value>
            <gx:value>113</gx:value>
          </gx:SimpleArrayData>

If you use the track icon style the heading is dynamically oriented at the current heading as you animate the path.

UPDATE: as Peter commented, the use of the gx: namespace is a Google extension which works fine with Google products but the KML may not work as expected with non-Google products.