tuonbondol / trekme

Offline maps Android application. Uses GPS coupled with TileView to provide smooth localisation experience.

1. Overview
2. Features summary
3. Create a map

• Select an area
• From an archive
• Manual map creation

4. Features

• Measure a distance
• Show the speed
• Add markers
• Add a landmark
• Import a GPX track
• GPX recording

Overview

TrekMe is an Android app to get live position on a map and other useful information, without ever needing an internet connection (except when creating a map). It differs from other map apps in the source of maps. Usually, a map is downloaded from the internet and is sometimes cached for an offline access (e.g google map). TrekMe is designed for people willing to use particular maps like USGS in USA, or IGN in France for example. You can also use your own map if you possess a paper map and you want to use it for your next trek. In this case, just scan it, then prepare and view it in TrekMe (see below). It also works if you possess a huge single file (several Gb), as TrekMe is designed to work with arbitrary map size. The only limitation is the memory available on your device (smartphone, tablet).

Features summary

• Support in-app map creation from:
  • United States's USGS
  • France IGN (requires a ** free ** registration)
  • Spain IGN
  • OpenStreetMap
• Marker support (with optional comments)
• GPX tracks import
• Lock the view to the current position
• Orientation indicator
• Speed indicator
• Distance indicator
• GPX track recording

Create a map

There are three ways to create a map:

1. Select an area from an official source provider like IGN or USGS
2. Import from an archive
3. Make it yourself (the hard way)

The preferred and easiest way is the first one. Below are detailed each methods.

Select an area

In this mode, you use a specific map provider. Google map is a well known example of map provider. But their maps aren't ideal for hiking. When possible, it is better to use maps with more terrain details.

For example, France's IGN is ideal when you are in France and its territories (Guadeloupe, Martinique, Réunion, Tahiti, etc.). There is also USGS for the USA. But not all countries have similar service, so sometimes you will have to fallback to OpenStreetMap or Google map.

Some providers require you to subscribe to download their maps. This step is free for individuals, unless you have specific needs like heavy loads for your organization.

From the "Create map" option menu, you get to choose between available providers:

Except for France's IGN, for which a (free) subscription is required, you can directly select the provider and continue.

From there, you can zoom into the area in the world you want to capture. Then, press the area button so an erea of selection appears on the screen. This area can be resized. Beware that USGS only provides detailed levels for USA, the same way that IGN details France and its territories. OpenStreetMap covers the entire world.

When you're done, press the download button, at the bottom right. A configuration menu pops up:

WMTS map providers have different zoom levels, generally from 1 to 18. In most cases, you don't want levels 1 to 10 for your hike, and level 18 is not always necessary. This is why the default presets have the minimum and maximum levels to 12 and 17 respectively.

The number of tiles that will be downloaded depends on your choice of minimum and maximum levels. The lower the minimum zoom, and the higher the maximum zoom, the greater is number of tiles. This is indicated by the "number of transactions". Downloading thousands of transactions may take hours.. so choose carefully your area and levels to only download the tiles you actually need.

Finally, press the download button. A download service is launched and you get a notification. From the notification center of your Android device, you can either:

• See the download progression
• Cancel the download

When the service finishes the download, you get a notification and a new map is available in the map list. It is already calibrated and ready to be used. You can set a presentation image so you can easily identify it in the map list. To do so, press the edit button at the bottom left of the map card (in the map list menu).

From the map configuration view, you can:

• Change the thumbnail image
• Change the projection (only if you know what you're doing)
• Change the calibration points (only if you know what you're doing)
• Change the name
• Delete the map

Import from an archive

In this mode you use an archive made from an existing TrekMe map. The archive can be made by yourself or someone else. A map can be archived from the map list menu, using the save button at the bottom right corner:

This creates a zip file (which we call archive) inside the trekme/archives folder of your device's SD card. To use someone else's archive:

1. Copy the zip file inside the trekme folder or any of its subdirectories
2. Menu > Import
3. Click the import button of the archive of your choice

This archive feature can also be used for backup purposes, as everything related to the map is saved (calibration, routes, points of interest, etc.).

Manual map creation - the hard way

In this mode, basic understanding of localisation on a map is required. However, efforts are made to make this app as easy to use as possible.

It is advised to be familiar with the following terms: Map projection, WGS84, Mercator.

Beginners are strongly advised to read the Technical Basis from the User Guide.

Then, proceed with the Manual map creation guide.

Features

Measure a distance

This is an option from the top-right menu while viewing a map. Adjust the distance by dragging two blue circles. This is a "as the crow flies" distance.

Show the speed

The speed indicator overlays the speed in km/h at the top of the screen. Note that it requires a few seconds before the speed can be displayed.

Then choose "Show the speed". If your screen is large enough, there is an icon to directly access it.

Add markers

Press the marker button to add a new marker at the center of the screen:

With its reds arrows turning around it, its shows that it can be moved by dragging the blue circle. When you're satisfied with its position, tap on the red circle at the center. It then morphs to its static form.

Tapping a marker displays a popup:

From here you can:

• Edit the marker (change its name and set a comment, see below)
• Delete it
• Move it

Here is the marker edition view:

Nothing is changed until you save your changes.

Add landmarks

A landmark is a specific marker. A purple line is drawn between it and your current position. So it helps when you need to always know the direction of a specific place, which may be outside of the area that your screen covers.

To add a landmark, it is the same logic as for markers. But this time we use the lighthouse icon.

Often, we want to display our orientation in the same time. We can also add several landmarks:

Import a GPX track

While viewing a map, press the button below on the upper right corner :

Then, a list of currently available tracks opens up:

Here you can:

• Import a new gpx files using the import button
• Manage track visibility
• Remove tracks by swiping them left or right

GPX recording

It is possible to record your position and create a GPX file, to later import into a map or share with other people.

From the "GPX Record" option menu, you get the following interface:

The recording can be started or stopped from the control panel. When recording, the location service runs in the background. It continues even if TrekMe is stopped or paused. An indicator reports back the status of the location service. A panel shows the list of recordings.

From there, when selecting a track, there are three buttons at the bottom which enable you to :

• rename it
• import it into an existing map (press the import button at the bottom of the list, then choose the map)
• share it

Multiple-selection mode

To switch to multiple-selection mode, long-press a recording. To revert back to single selection mode, long press again somewhere in the list.

Share recordings

Whatever the selection mode, the share button below is available:

Delete a recording

To delete a recording, activate the multiple-selection mode. A remove button appears at the bottom right.