EM406 giving fluctuating readings of Lat and Long, hard to detect real movement

Good night, I am trying to detect movement with the EM406. I was originally trying to use the speed given by the module checking if it was different to 0, but it is never 0. And when I checked the lat and long it always fluctuates, so i had to check differences in readings with the initial ones. But it fluctuates so much that it detects movement at more or less 15 mts.

My question, I don't think so, but is there a way to avoid this with this same module? or is there another module that I can use with this serial communication with arduino that doesn't give the readings with such fluctuation?

Where do you test it? Indoors? This module has a built-in patch antenna which give you an acceptable reception outdoors with more or less clear sight to the horizon. Use a GPS module with an external antenna (and use a good one) if you want to use your project in cities. Don't expect a good signal inside of buildings.

I ran the tests indoors, today I’m going see if it’s possible to test it outdoors, if not it will be tomorrow. But should I expect the same behavior with the module inside of a car?

But should I expect the same behavior with the module inside of a car?

Put the module under the front window and you'll probably see almost the same results as outdoors but inside the motor space (under all that metal) I'll expect even worse results. The less shielding you have against the sky the better the results will be.

Thanks pylon, I will test it that way.