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I am very impressed with the bangle algorithm.
Just to be clear are you saying you are using the B2 algorithm on a SN80 and getting these results ? If so that is really encouraging.
Personally, I am interested in measuring steps as a proxy for distance during walks
Its an ok approximation method providing you work out the stride distance or have a setting for stride distance. You will know it will be different for each person depending on height. I know for me that 2000 steps (on a pavement) is 1 mile. But walking on tracks, grass, mud etc etc, stride length changes a lot.
I have not tested how accurate the Recorder calculation of distance is using the GPS trace. It may suffer from the bug I just fixed in the RUN app where the distance between two lat/lon's was not an accurate calculation. The 0.03 of RUN app should be good now.
I would definitely recommend you take a look at the RUN App. You can use it with GPS on / off. One option would be to add a stride length and when the GPS is off to estimate PACE and distance based on steps*stride length. Would save a lot of battery.
HughB-
Yes, it’s the B2 algorithm on a SN80. I programmed the first version of plot track for B1 that Gordon then added to the gps recorder app and it used exactly the equirectangular approximation you have suggested for the Run app. I have just checked and the current version still uses it so the distance should be accurate as I did check its accuracy at the time.
jeffmer
@HughB Your work with Gordon on the Pedometer is very much appreciated. I thought you might be interested in the results I have been getting using it with a different accelerometer the sc7a20 which is found in a lot of watches such as the P8, ROCK, Magic3 and SN80. The sc7a20 is a very cheap device which sells for pennies and many examples have readings that are well off centre. As a result, I have had to introduce calibration which Gordon has noted is not that simple. You have to gently move the watch into six different positions to get full calibration data - face- up/down, edge - up/down and end - up/down. However, I have only needed to calibate once. I have been comparing the step count during dog walks with that of my iPhone. The results for walking are quite impressive - here are two recent walks which are typical of the results I have been getting:
iPhone: 5121 SN80: 5124
iPhone: 5209 SN80: 5169
I have measured this walk at 2.6 miles with the Bangle GPS recorder. Personally, I am interested in measuring steps as a proxy for distance during walks - enabling step counting at the start of a walk and disabling at the end. I am very impressed with the bangle algorithm.
BTW: I have been using the old threshold of 14.