Hi first of all love the new 305!! But i’m having problems with my elevation. Its all over the place. I do this run and at my 1km mark for some runs are really out ie. 51m, 26m, 30 m… Does this just have to do with the satalites? Its in a really open area… so good coverage… and 2 of the 3 run have been around the same time… Plus today on my run home, i noticed that my pace was like really out it was around 9min/km but when i did my lap count for 1km it was at 5:30 1km… And it was in a stright line. for about more than 1km… (as i do notice if i run a trail with alot of turns the pace takes time to get right)
I had a few issues with mine and contacted the Motionbased.com (www.motionbased.com) guys. They told me to update the firmware to 2.4, and also to turn on the smart recording. These two things made the difference.
Try smart recording and see if it changes. obviously if you’re going to go over 3.5 hours, you’ll need to change it back. It has worked for me.
I do not know the technical aspects of the differences between the two. Obviously the smart setting records more data points, but I don’t know how or why it is “smart”. Ask the techies on the motionbased forum for that one.
I hope you are right about the upgrade to 2.4, but I’m skeptical. I already had set the system to “smart recording”. I asked Garmin customer service and they said elevation/calorie issue was a know problem and that “their engineers” were working on it. I upgraded the firmware to 2.4 last night so we’ll see. But this has been a problem going back to the 201, so I wonder if there will ever be accurate elevation readings from a GPS based system. Interestingly, the Edge series GPS units use a barometric altimeter instead of the GPS to calculate elevation, as does the Polar S625X.
My old 301, combined with motionbased’s gravity correction comes out very cleanly and just about perfect as far as I can tell. The 305 has been a bit disappointing so far in that regard, but it is good to hear garmin isn’t satisfied with it either.
The elevation on most gps units is usually less accurate than the positioning. Some of the software programs out there will cross check the gps elevation with the usgs topos which helps. I’m not sure if motionbased has that feature or not.
There seems to be a general misunderstanding of smart recording in this thread. There are two options for recording: smart and every second. Every second creates the most trackpoint dense activity and the 05 units only have enough capacity to store 3.5 hours of data recorded at every second. Smart recording on the other hand is a bit more variable as trackpoints are dropped only when the unit feels it is necessary–this can be every second or 2,3,4,5 etc. Using smart recording allows a much greater amount of recording time than every second–up to about 13,000 points can be recorded. It is recommended for best results to generally use smart recording and only use every second for particular activities where trackpoint density is important–track workouts, crits, twisty courses, etc. Due to current state of technology some GPS noise is unavoidable, however, using every second recording tends to make this more of an issue as the smart recording allows a little greater smoothing of your data.
Elevation: GPS elevation is and has been problematic since the 201s and isn’t a whole lot better with the FR305s (the Edge 305s have a barometric altimeter, the forerunners do not). Using a program like Motionbased to analyze data post activity can help with many activities as MB has a feature which allows elevation correction based on dataset of known elevations associated with trackpoints, but this doesn’t do much for real time info. There is of course always hope Garmin can make improvements with future firmware releases but I’m not hopeful as GPS elevation just seems naturally unreliable.
Pace: Current pace is a feature I still feel needs a good amount of tweaking and you may find your results improve by applying different levels of smoothing. I myself have gone a different route and use a combination of lap pace (with unit set to autolap on the mile)/avg pace on one screen to get a more accurate sense of my pace info. Trading off some instantaneous feedback for more reliable data has been a decent trade off for me. YMMV.