You can do a concatenated merge where you combine GPS files end-to-end. This is common in situations where your GPS died or ran out of battery and you started a new recording on your phone or some other device. These are merged end-to-end, and it is a relatively simple type of merge. You just add everything together.
The other type of merge that you can do on GOTOES is an overlapping merge. This is extremely useful for activities where you are recording with two separate devices, and one of the devices has a data field you want (but the other device does not support). GOTOES can put it all together in one file. A simple example is if you have a "dumb" trainer and a heart rate monitor recording separately. GOTOES can collapse the data.
The problem arrises on overlapping merges when two devices record duplicate streams. In that situation, the user needs to select a preferred stream. At this point, I want to give the user ultimate flexibility (rather than choosing for them)... but this can result in confusion on the user's part when they get "double distance" or heart rate that zig-zags up and down. In the future, I may try and encode "smart stream selection" but in the near-term, it's up to the user to decide which stream to include. I have posted two screenshots so you can see the outcome of the various selections, and how you can resolve this issue:
- Two distance streams selected on overlapping files will cause "double distance". The way to fix this is to only select ONE distance stream for your project.
- Here is a "correct" way to merge distance, however note that the user has still double-checked Elevation and heart rate. That means that the end result will oscillate between the elevation/heart rate for these two files. That may lead to confusing or jagged graphs.