I am currently working on redesigning a SirfIII based battery operated GPS logger. A MTK3339 based GPS module has been selected due to overall (advertised) performance.
The GPS logger uses a microcontroller to enable the GPS receiver in a periodic time interval, waits for a position and then turn off the receiver (leaving backup supply enabled that keeps the ephemeris data in RAM, allowing faster TTFF).
After some testing the results show that the old SirfIII logger is still outperforming the new MTK3339 version. Standby current of the new logger is only 1/4th of the old design. Closer investigation showed now that the SirfIII GPS chip is featuring a special mode called Sirfaware. This is resulting in 50-75% shorter position acquisition times compared to MTK3339.
a) Is anyone using MTK based GPS modules and found a way to improve position acquisition or overall power consumption?
b) Is MTK3339 the right choice for a battery operated logging application?