I've made a few more changes to GPSLog Labs to better support heart rate logging:

• Heart rate data can now be filtered!

  These filters work in the same way as the other GPS data filters and can be added to individual logs or to tags so they are added automatically.

  There are 3 heart rate filters, one takes the median heart rate, one the average (mean) heart rate and the last one is a special filter to clean up noisy heart rate data during your warm-up where the heart rate strap doesn't record properly until you've built up a bit of a sweat.

  

  You put in a "warm up time" (7 minutes in the above image) and it will discard any readings that are too high during that period. It assumes your heart rate after you've warmed up is higher than when you're warming up which is pretty rough, but it cleans up a lot of messy data.

• Additional heart rate log files can be uploaded in .zip files
• The tag detail page summary tab now has "box whisker" plots for the heart rate distributions
  

Some other recent changes include:

• Speed zones
  

  These are configured per tag like heart rate training zones and will be displayed in the background of the activity tables to give you an indication of the intensity of the activity.

  
• The Speed Average filter has been changed from an exponential average to a regular mean, so it no longer "lags" behind the signal.
• The Speed Median and Speed Average filters have also had a cutoff added to preserve stops, any data below that threshold won't be filtered.
• The GPSLog Labs home page has a new layout that highlights some key features a little more prominently.
• Alert & confirm popups use the alertify.js library.
• Support for the Garmin FIT file format has been added.

The last few months have seen some minor updates to GPSLog Labs and a bunch of major heart rate logging related features that will be in a post of their own.

• "Race results". This is a new visualisation available on the Best Efforts tab for Tags and Routes.
  It takes the best efforts at a given distance from all of your activity and shows a "photo finish" of where each log would be as the "winner" crossed the line.
  Choose the distance to be compared by clicking on the column headings of the best efforts table.
  Some of the results may be collapsed so the chart doesn't take up too much space.
  
• Together with the "Race results" there's also a histogram of Average Speed/Pace.
  It's actually a few histograms overlayed, the darkest bars are the count from the last few months, the lightest the count for all time. This means you can see if there's a pattern to your recent activity that differs from the rest.
  
• The Uploaded log file page has a new tab, Edit Activity (junk hidden) that lets you edit the places & tags without being distracted by the junk segments and merge points.
  
• There's a new "Remove Stops" filter to clean up maps of hikes or walks where otherwise there would be too many stop markers.
  This is a bit of a hack, but it allows you to filter out stops which are shorter than the threshold. Unfortunately it does that by substituting a speed of 1km/h during the stop, which will mess with the average speed stats, so this filter should only be used where those stats are not too important.
• The Tag map now has an option to show log colours "By route" or "By direction". Choosing "By route" can help find logs that may have been mis-classified or to find logs that could be grouped together into a new route.

GPSLog Labs' Position Filter now has a new "tunnel mode" that interpolates along a custom path instead of a straight line so resulting distances and speeds are more accurate.

This is easiest to illustrate with an example: A route I regularly run goes under a raised freeway for about 500m. Throughout this section, the GPS signal is unreliable and the following map shows the kind of quality of track I can expect:

Picking one of these logs in particular shows that it's probably got the wrong distance and the speeds will be way off too, not very useful.

So, to fix this up, click on Filters in the right-hand side panel of the activity detail page:

Then add a filter:

And choose the Position filter:

First you'll need to position the "discard" circle over the area of the track you wish to delete.

By default, the discarded point from your track will be replaced with a straight line through the circle. This is likely to result in an incorrect overall distance being calculated for your track (i.e. it'll be too short and the average speed will be to low too.)

To add a line of waypoints to interpolate the track through, click the Add Waypoints button then click on the map to draw the new path through the area.

Double-click to stop drawing the line, and drag the points to edit them, clicking a point will delete it.

Once the filter is saved and the edit page reloaded, the discarded points will be shown as small markers.

The following graph shows how the new track is interpolated through the waypoints at a constant speed, so stopped time will be counted in your average speed.

And back on the activity detail page, there's a nice cleaned up track that shows where I actually went, much better!

Like other filters, the Position filter can be saved to a tag so it will automatically be applied for any appropriate activity passing through that noisy signal area, meaning you'll never have to deal with messed up GPS data again.

A problem you'll encounter very quickly when using a GPS logger is "splats" in your log files caused by a bad signal while you're inside a building or other area with lots of signal reflections.

This can be very annoying as it will often create spikes in your speed that completely mess up any maximum speed or distance statistics for that log file.

For a while, GPSLog Labs has had "position" and "time" filters that let you manually remove these "splats" but it was tedious to get right, so now a simpler "splat filter" has been added that makes the process much less painful.

First, go to the activity you want to filter and click on the Filters link in the side panel:

Then click "Add a filter" and choose "Splat filter":

On the Splat filter page, you need to drag the marker so that it covers the "door" of the building. It doesn't have to cover all of the spikes of the splat, you just need to capture the last good point before you enter the building and the first good point when you get out and start getting a good signal again.

As you can see, the marker is only covering the actual building under the splat, not the whole splat.

The Splat filter will then discard all the points while you were inside the building and interpolate over the gap (which will give you a long period of very slow or 0 speed, restoring the stats of your log back to something sane):

The results are dramatically better, the distance and maximum speed are both now much more accurate and representative. This log also included the Static Navigation filter as the AMOD AGL 3080 logger was quite bad for logging at walking speeds.

Enjoy!

• There's another new button on the edit Log File tab exposing a feature that was previously a little too well hidden, this time to select which segments should be marked as "junk":
  

  That brings up a popup where you can quickly choose which segments are junk (and therefore shouldn't be displayed in the rest of the site) and which have the activity you're interested in:

  
• The colour of the junk segments on that page has been changed subtly from red/orange to a more neutral gray too.
• The GPS Data Filters page has been completely overhauled too so it should hopefully be a bit easier to use and faster to add certain type of filters too.

  Click on the Filters side panel of an activity you want to filter:

  
  The GPS Data Filters page now has clearer menu options and a bigger preview maps and graphs to show the results of the filters you have applied:
  
  And the individual filter pages now have more space to show their options and view the maps and graphs:
  
• The Time filter now has a preview map to show you the segment that is being discarded.
• Most filters now have a "Copy to tag" menu option that will let you copy the filter and it's parameters to a tag. This means that once you find a good combination of filters to clean up your activity, you can have them automatically applied to all data you upload from now on tagged with that tag.

Updates on the updates to GPSLog Labs are lagging a bit, but here's some of what's been happening lately:

• The log file chopping logic has been tweaked a little to hopefully avoid creating as many unwanted "unnamed places":
  - Auto created places must now be further away from known places before they'll be created.
  - Auto created places won't be used to chop logs between known places. If you do want the auto created place, after you name it, if you reprocess the log then it will be cut properly.
  - There were also a few bug fixes that should make detection of places more accurate.
• There's better support for editing and filtering of large log files.
• The little milestone markers now have a small arrow attached to indicate the approximate direction of travel at that point:
  
• There's now a filter on the logs tab for a place that lets you narrow down the activity by tag:
  
• The log file editing page has been tweaked to make finding some of the commands easier, the menu now includes the "Add a Place" and "Manually create segments" commands that were previously a little hard for some users to find:
  

  It's now possible to change the Route or Tags directly from the edit page for an activity after they have been set:

  
• The "Select tags" popup now allows quick selection of sets of tags from those used previously on other activity on the same route:
  
• Speed vs time graphs when you're editing and filtering log files now have a "scale" selection, that will allow you to see detail in log files which was previously hidden by large speed spikes caused by GPS errors:
  
  In this example, the actual activity is completely obscured by the 5,000 km/h errors... Selecting a maximum of 50 km/h on the scale means you can see the activity properly and edit it as required:
  
• There's a new "Inverse position filter" available, that is the opposite of the Position filter. i.e. it will discard points outside the given circle.

• Florian is doing a great job translating the site into German, danke schön!
  
• The Summary tab on a tag detail page will show a table breaking down the activity for that tag by other tags where appropriate:
  
• The Distance vs Time graph on a tag detail page now shows a line through the mouse position that let's you see at a glance which logs are faster, slower or the same speed:
  
• Table rows are now highlighted as you hover the mouse over them.
• GPS Data Filter editing has been improved to make it more obvious that the items can be dragged to re-arrange the order that they are applied:
  

On a run the other day, my GPS logger (an AMOD AGL3080) recorded a really noisy signal and the resulting trace was inaccurate for the first 10 minutes. I have no idea why it did this, the second 10 minutes were fine.

The end result was a log which was almost unusable, the distance recorded was twice what it should be and the average speed was way off.

By experimenting with the Speed Filter I was able to find a set of filters that cleaned the log up remarkably, meaning I could include it in my training stats after all. The following graph and map show the discarded points and the resulting "cleaned" data:

The red points are discarded by a Radius Filter as that section of the route goes down a lane-way where the signal is generally very bad.

The green points are discarded by the Speed Filter and show how bad the signal was for the first 10 minutes.

The speed is smoothed with a 10 second Speed Median filter too, but the discard filters do the bulk of the work.

I had to experiment with the Speed Filter parameters by varying the cut-off speed until the log's distance was correct (based on previous logs along the same route). When the cut-off was too high, the resulting distance was still too long, and when it was too low, too many points were discarded and it was too short. Once the distance was right, the resulting average speeds were reasonable enough for me to be able to use them. As the table of before and after stats shows, the results were pretty dramatic:

This is the most successful filtering of a log I've seen so far, generally it's removing much smaller amounts of noise, and it's great to know it can be this powerful. I hope some other GPSLog Labs users can get similar results too as it's very frustrating when a log of your activity doesn't record well and is unusable.

The new GPS track filters in GPSLog Labs are powerful, but if you had to configure them by hand for every log that you uploaded, they wouldn't be much use.

Thankfully, the real power of the filters is that they can be attached to tags, and then when that tag is assigned to a log the filters will be copied across automatically.

This means you can configure a set of filters for all your logs tagged with Run, and you can have a different set of filters for Bike Ride. For example, you may want to tweak the sample window size on the Median filter as the average speed will vary less when running than when bike riding so the filter can be a bit more aggressive.

The process for adding filters to a tag is the same as for a log, the difference is that you can't see what is being matched by the filter, so I suggest you get the filter working on a log then copy the details across to the tag so it is automatically applied to other logs.

Note that the filters are only automatically copied across to the log when the tag is assigned to the log and you have not modified the log filters. You can click the Reset button on the log filters page to restore it to the defaults for the tag.

As always, let me know if you have any difficulties or suggestions, and I hope you enjoy this new functionality.

In addition to the automatic discard filters, GPSLog Labs has 2 "manual" filters you can use to clean bad data out of GPS tracks that the automatic filters can't handle.

Manual Filter

This filter lets you discard logged data between two times. E.g. if you spent some time inside a building and got spurious signals as a result, you can "zero out" the data between when you entered the building and when you left.

Select the time range by highlighting the portion of the log on the graph, or adjusting the slider, or keying the times into the text boxes:

The data between those two times will be discarded and GPSLog Labs will interpolate the log between the remaining points:

You can use as many manual discard filters as necessary to clean up your log.

Radius Filter

This filter lets you discard logged data in a specified area. E.g. if you have travelled between buildings or through an underpass where you get bad signals you can zero all points within that area.

Select the area to remove by moving the marker on the map and adjusting the radius:

The data between within the selected area will be discarded and GPSLog Labs will interpolate the log along a straight line between the remaining points. This won't be perfect, but will be better than the original noisy data. Like Places, the discard filter is "sticky" so that if the track leaves the radius briefly (less than 60 seconds) it will discard everything between the first point inside the radius and the last. This should mean you don't have to make the radius too large and will still be able to capture all the bad points.

You can use as many radius discard filters as necessary to clean up your log.