Yes, the number of positions acquired per second. High rates are good to get smooth lines and better understanding of min / max points (e.g. braking position). On the other hand, high rates put higher load on the system which in turn may lead to other problems (like lost satellite locks, missing DGPS).
This means you need to see the sum of several dimensions to judge a sensor:
Update rate (# of position per second)
Accuracy delivered (accuracy of individual positions)
Lock stability (low stability means to get drop outs, i. e. missing fixes when receiving condition get difficult)
Just to give an example: both XGPS150 and UltiMate deliver 5 Hz at very high accuracy - but they lose the lock regularly in a difficult turn on my home track Nordschleife (namely "Bergwerk"). Opposed to that, the older TomTom car kit delivered only 1 Hz at high (but not very high) accuracy, but NEVER lost the lock in this turn.
Harry wrote:Yes, the number of positions acquired per second.
I've been logging 3.9 Hz using an iP4, the Dual GPS and BT-1 for OBD. My iP5 would be better but it's 16 GB and nearly full with music, etc. I had retired the iP4 and instead of selling it, I converted it to a 'touch', i.e., there's no sim card so it can't be used as a phone. But all 16 GB are dedicated to HTL and it functions well. Perhaps when I next buy an iPhone, I'll buy a 32 GB version so that I can use it for everything. Dave
09 Carrera S - Black, 6 sp, Carrera red full leather with deviating black, adaptives, navi, XM, etc
06 Cayenne S - Crystal silver, air suspension, bi-xenon, navi, sirius, etc
I have a iP5 16gb and have about 3gb free... should be enough? i'll just log a day and export it to the laptop then the next day do the same as i'm there for 3 days.. or are the files THAT big? (by a day I mean about 6/7 sessions of around 20mins everyday)
I have a track day Nov 3rd that I'm getting ready for. I just picked up a mount, a Optrix XD5 case only to find out that the iphone GPS receiver basically sucks. Since the location of this particular track doesn't offer much for cell service I figured it would be best if I had an external GPS receiver.
I would go with the Emprum but since I'm on a motorcycle it isn't ideal due to the need for a 2nd connector (lightning adapter) that will almost certainly vibrate lose while on track. I'd really like a 10hz sample rate if at all possible.
Bad Elfs are iOS compatible but do not allow a connection using LapTimer's direct sensor integration - not recommended. Qstarz has no iOS compatible GPS at all, don't know why. In case you want a good 10 Hz GPS for LapTimer, please opt for the XGPS160. It is very good. The full compatibility list is avaialble on http://www.gps-laptimer.de/Compatibility.html
Different for a bike as I've got the ram mount stuck to the windscreen! But the adapter and Emprum have not came loose. Only problem I've had, is the cheap usb charger lead from eBay dying.
Harry - thanks for the update. I was hoping bad elf may have improved their product. Sounds like I'll be going with one of the dual electronics devices
Limp - Honestly I'd love to plug into the lightning port. I just dont trust it at speed on the bike. Lots of wind and vibration. Wish I had an on-board charging solution. My only option is to charge between track sessions.