[Talk-us-massachusetts] GPS Data Logger Recommendation?

[Greg Troxel]

Hobbit's advice is good.

Newer android phones (pixel 5 at least) have dual-frequency GNSS which
is better.  Newer iphones might too but apple thinks different and it's
near impossible to get status out of them.

I have a Garmin Etrex 30 which I find works better than phones.  Looks
like it can be had used for $155.  However you don't need bigger
memory, color or preloaded maps for this to work.   But it is not so
much better that I would recommend spending money on it.

With all of these, you'll only get 10m class accuracy, and you can
squint to sort 5 with multiple tracks.  But even 10m on trails will be
hard for almost anyone to say it's off.  I put trails in this way for
years and only with RTK could I tell they were off.  Nobody ever
complained.

The next level is RTK, which is a budget more like $700 at least and a
lot of fiddling, but you can get trails to sub-meter.