RE: Field verification of GNSS on the nRF91 Series

JaniM — Thu, 08 May 2025 12:32:13 GMT

Hello,

Cold start is one example, first fix is very different measurement than the following TTFF measurements if device/GNSS receiver is kept up and running and no acquired information by the GNSS receiver (Ephemerides, Time and TCXO offset etc) has been tampered/removed intentionally by the user.

Depending then on the measurement interval the GNSS received is then either in Hot Start or Warm Start mode after the initial Cold Start fix.

Having TTFF measurements performed with A-GNSS included (A-GPS, if there's not assistance data for other constellations) it is then something in between Cold Start and Hot Start operating modes, something similar to Warm Start roughly.

I hope this helps!

Br,

Jani M

RE: Field verification of GNSS on the nRF91 Series

Roman Veselskyi — Thu, 10 Apr 2025 14:59:11 GMT

"Please note that the very first fix after device start-up is a rather different measurement than any of the following consecutive fixes. "

May you please tell more about it? Does it also relate to the A-GPS?