How do I display a track?

There are two ways to load GPX files into the Trkd Maps web service.

	Click the load button on the toolbar, and choose a file from the panel that appears.
	Alternatively, drag a file from your desktop and drop it onto the map in the browser window.

How can I display more than one track?

Any file loaded will be added to the existing map, so you can display several tracks together. Files can be loaded one by one, or by selecting a group together, e.g. using Shift-click, Ctrl-click or right-click.

How do I identify a track on the map?

Use the mouse pointer to hover over any track marker to display its filename.

How can I see details of a track on the map?

	Click on any stop or pause marker to display details of the track.
	Duration Distance Average speed

Track details can also be opened automatically using the track default settings.

How do I change between km and miles?

	Click the settings button, and select Settings from the top dropdown menu.
	Select miles or km from the Units dropdown menu.
	Click the back button to return to the map.

How do I change the appearance, e.g. colour, of a track?

	Click the settings button, and select the track name from the top dropdown menu.†
	Make the required changes on the track settings screen.
	Click the back button to return to the map.

^† Quickly select a track's settings by right-clicking (Ctrl-click on Macs) on the track.

How do I change the appearance, e.g. colour, of all tracks?

	Click the settings button, and select Settings from the top dropdown menu.
	Make the required changes to the track defaults.
	Click the Apply button to change the current tracks.
	Click the back button to return to the map.

How can I see the map obscured by a track?

	Click the visibility button on the toolbar to hide all the tracks.
	While they are hidden, click it again to display them.

How do I delete a track from the map?

	Click the settings button, and select the track name from the top dropdown menu.†
	Click the Delete button.

^† Quickly select a track's settings by right-clicking (Ctrl-click on Macs) on the track.

How do I delete all tracks from the map?

Click the clear button on the toolbar.

How do I select different maps, e.g. Ordnance Survey?

	Click the settings button, and select Settings from the top dropdown menu.
	Select the map provider from the Map Data dropdown menu.
	Click the back button to return to the map, and a message confirms that your new map is loading.
	Click OK on the message, and wait for loading to finish.

Note: Some maps have limited coverage, e.g. Ordnance Survey only covers the UK.

How do I change language?

Click the language button on the toolbar, and select from the top dropdown menu.

We recommend choosing this setting before loading any tracks, as it requires the web page to reload and all tracks will be cleared from the map.

End FAQ

What does the data analyser do?

The analyser assesses the data quality of each track as it loads to automatically choose a suitable filter. It makes best use of the data recorded without further effort in most cases.

Users with specific needs can adjust the automatic analyser to suit their requirements, using the default filter settings, or can manually tune the filter to their data, as explained below.

How do I change the default filter settings?

	Click the settings button, and select Settings from the top dropdown menu.
	Change the default filter settings using the controls displayed.
	Click the back button to return to the map.

What do the default filter settings control?

The data analyser automatically filters out errors in Trkd GPS's GPX files to make best use of the data recorded.

• Filter Horizontal Accuracy: Toggle whether filtering is enabled.
• Filter Maximum: Set the maximum value for horizontal accuracy in metres after filtering. This eliminates larger errors to make the most of poorer quality data.
• Filter Percentage: Set the percentage of low-error points after filtering. This refines and improves better quality data.

Data quality depends on a number of factors, including the device used and GPS reception conditions at the location. As data are loaded, our proprietary algorithms assess its quality and automatically choose the initial filter settings.

How do I change the filter settings for a track?

	Click the settings button, and select the track name from the top dropdown menu.†
	Toggle the filter using the Filter Horizontal Accuracy checkbox, and tune it by setting the Filter Value as explained below.
	Changes are instantly displayed in the Current Filter and Filter Statistics.
	Click the back button to return to the map with the new settings applied.

^† Quickly select a track's settings by right-clicking (Ctrl-click on Macs) on the track.

What is the current filter?

The Current Filter displays m/n (p%, e)

• m is the number of points present after filtering.
• n is the total number of points in the unfiltered track.
• p is the percentage of points present after filtering.
• e is the maximum error, i.e. horizontal accuracy, present after filtering.

Together these numbers show how the Filter Value affects the data quality after filtering, to help the user identify a suitable choice. For example, 192/200 (96%, 30.0) means that 8 points have been filtered out leaving 96% of the data, with a maximum error of 30 metres in the remaining points.

What do the filter statistics show?

The Filter Statistics displays the data statistics after filtering.

• x̄ is the mean, which is a measure of the typical error size, i.e. how big.
• s is the standard deviation, which is a measure of the typical error range, i.e. how widely spread.

Larger mean values indicate higher average errors, and larger standard deviations indicate wider variations in the errors, so they are less predictable. In both cases, smaller values represent better quality data.

How do I manually tune the filter for my track?

Expert users can manually tune the filter as follows:

1. Disable the filter to see the unfiltered data statistics in Filter Statistics as a baseline for comparison.
2. Enable the filter to see the filtered data statistics. The Current Filter shows how many of the total points are used after filtering.
3. Compare the updated Filter Statistics with the unfiltered values to see how much the data quality has improved.
4. Filtering out more points decreases the error and improves the remaining data quality, which is good. However, this also reduces the size and resolution of the filtered data, which is bad. The aim is to balance these factors, and choose a filter which removes large errors, which incorrectly distort the route, while leaving enough data points to accurately represent the correct track on the map.
5. Experiment with different Filter Value maxima and percentages to find the best result for this track. Note that the filtering is increased by reducing the value or percentage.

Why are the filter controls disabled with 'no accuracy data'?

Accuracy information must be recorded in your GPX file to allow the data analyser to function. When the required data are not present, the filter controls are automatically disabled with the message No accuracy data.

To record these data, ensure that Settings->File->Content->Incl. H. Acc. is enabled in your copy of the Trkd GPS mobile app. Other GPX apps and devices may not record accuracy details, as they are an optional extension within the GPX standard.

Download our free Trkd Demo to try it for yourself.

End FAQ

Who else can see my tracks?

To use Trkd Maps, you must first copy your GPX files to a computer running a web browser that is connected to the internet.

• The files do not leave that computer.
• They are not sent across the Internet.
• They are not copied to a remote server.

The only people who can see them are those who have access to that computer.

If you are using a public-access computer, e.g. in an internet cafe or a library, we strongly recommend that you delete your GPX files from that computer after using Trkd Maps in order to protect your private information.

What are the other privacy issues?

Please read the Privacy section of the Trkd GPS FAQ for more information.

End FAQ

Why does loading my file give an error?

The error message indicates why there has been a problem. Here are the most common ones, with solutions.

Why does my GPX file not load into Trkd Maps?

Trkd Maps supports files which comply with the GPX standard.

1. Load your file into a text editor to confirm that it contains <trkpt> tags.
2. Ensure that your file is valid GPX, according to Topografix's guidance.
3. Report the issue to our support team, enclosing a copy of your GPX file.

End FAQ