I'm interested in knowing the maximum achievable update rate for a civilian GPS receiver. Specifically
- Receivers that depend exclusively on GPS satellites (e.g. not including IMU-based movement estimation to interpolate)
- The hypothetical limit (i.e excluding feasibility concerns, e.g. processing power)
- Update rate after lock (e.g. TTFF)
The fastest civilian receiver chips I've found have an update rate of 50Hz, such as the Venus838FLPx.
According to alex.forencich in this stackexchange thread, it might be "rather high":
It's difficult to pin a position update rate on the satellites as it's all in the receiver. The satellites simply transmit orbital ephemeris data and the time of day at 50 bits per second and a CDMA chip rate of 1.023 MHz, all precisely phase locked to an atomic frequency standard. The GPS receiver maintains a lock on the CDMA spreading code and uses that to determine the time of arrival differences between the satellites. Getting a lock in the first place takes a while, but after that the position can be updated at a rather high frequency. I'm not sure what the upper limit on that is.
And this is of course unrelated to the CoCom speed and altitude limits for civilian receivers.
That's what I've found.