Recommendation for choosing the GPS GNSS element

Disclaimer:

• lets split GPS Modules and GPS Antenna, because it's a different thing's, but can be as one element called - "GPS"
• Global Positioning System (GPS) - was created and realized by the USA. GPS also known as NAVSTAR GPS.
• GLONASS/ГЛОНАСС - was created by and realized by Soviet Union now it's belong to the Russian Federation.
• Global Navigation Satellite System (GNSS) - a satellite navigation system is a system of satellites that provide autonomous geo-spatial positioning with global coverage. For now - only the United States NAVSTAR GPS and the Russian GLONASS are global operational GNSSs.
• maximum precision you get from GPS element's with price below 1000$ is 2.0-2.5 meters. Interesting why - read below.

Mostly you can buy a GPS/GNSS element with or without compass built on U-Blox modules. On today U-Blox (01/2015) propose 3 series:

• 6 generation - only GPS
• 7 generation - GPS or GLONASS (it can work only with GPS or GLONASS, not GPS+GLONASS togeather!)
• 8 generation - GPS and GLONAS (GPS+GLONASS) also all this generation work with SBAS - but mostly precision of that systems is not enough for the UAVs, so this parameter we will not describe here.

All this generation have product's line like - NEO, LEA, MAX and else. My recommendation to buy NEO product line - because all parameters almost identical except price, if not - than mostly of that parameters be unused or unneeded it in UAV's - NEO product line is the cheapest and the best for our needs.

NEO product line have sub lines that marks with letters - M, L, Q, P. We choose M, else sub lines has almost the same parameters but how I said before it will be unused or unneeded.

Summary: you must buy NEO-6M series or NEO-M8 series.

If you want know some more about accuracy - you can continue to read here.