3 ms·
These watches don't have anywhere near 12 day life with the GPS enabled. Depending on the watch and the temperature it is anywhere from 2 to 30 hours.
by persistent 7y ago
These watches don't have anywhere near 12 day life with the GPS enabled. Depending on the watch and the temperature it is anywhere from 2 to 30 hours.
- billziss 7y agoGood catch! From the Garmin MARQ Aviator page: > Smartwatch mode: Up to 12 days > GPS mode: Up to 28 hours > GPS with Music: Up to 9 hours > UltraTrac™ mode: Up to 48 hours
- dfox 7y agoAlmost any GNSS receiver is by design power hungry. Modern mostly SDR constructions have faster time to (reasonable) fix, but still it involves large amounts of essentially opportunistic computantion to acquire and track the CDMA downlinks. This is one of the arguments why Spy-Fi style inconspicuous and globally accurate and useful trackers are nonsense. The whole process of associating with 2G GSM network and sending one MO-SM message is incredibly energy expensive, but getting reasonable GNSS fix is in completely different barpark.
- mNovak 7y agoPossibly more feasible if you periodically capture and store a few ms raw IQ, then transfer a quick burst when the handler comes near, to do the nav solution offline.
- angry_octet 7y agoYep, there are a number of offline ways to solve for position. It needs 200-500mS of GNSS signal. I like the Yabby: https://www.digitalmatter.com/Devices/Lorawan-Trackers/Yabby-LoRaWAN https://www.digitalmatter.com/Devices/Lorawan-Trackers/Yabby... Also: http://chipfox.cz/ http://chipfox.cz/