Wanted: a small and simple script to check if some data set is valid JTT or not.

I have thrown out some stuff at http://solveig.oslo.no/anchoring-jtt.json, but I'm not sure if it's valid or not.

My son is trying to work on some presentation layer based on that json blob.

Good start. Where are we now?

Surprised I can't find any kind of standard or recommended JSON format for GPS data beyond this nascent effort. SNON is not suitable as it treats location as a sensed value or a fixed sensor attribute, rather than a spatio-temporal dimension.

it might make sense to have registries for various concepts, so that on the one hand consensus can evolve around well-known concepts, whereas on the other hand the format can evolve by allowing new concepts if there is demand and consensus. here's an initial list of ideas:

• activity types (such as run/bike/swim) might be useful. the problem with these is that they often are not very well-defined, and potentially overlapping (bike could be useful, but "road bike" and "mountain bike" might be even more useful for some). maybe have a sub-field for detailed/additional info?
• measurement types might be useful, such as measurements for heart rate, temperature, and various others. once again, setting the scope can be tricky, for example there are datasets out there that have measurements both for water and air temperature.

the current (extremely primitive) model assumes that a track may have multiple segments (a track is an array of segments, which then is an array of data points). that's based on GPX's model, where segments should be treated (i think) as potentially disconnected parts of an activity.
TCX is much more complicated: there can me multiple activities, each activity can have multiple laps, and each lap can have multiple tracks. i am not even sure it's entirely clear how to use this hierarchy (if somebody knows, please let me know!), but the main question here is: how should JTT model this?
there probably are good cases to be made for "laps" (people automatically or manually marking "segments" of their activities) and "segments" (for example, stopping the watch and restarting, potentially after moving). any preferences on how to handle this in JTT?