Glue Trail

 


Glue Trail is a GPS-enabled system for navigating outdoor trails where network-based maps are non-existent or details are too sparse to be useful; it lets you navigate any image source on your handset by gluing it onto a specific geographical location, turning that image into a trail map that will scroll relative to your current location. You can even record a track in real time, as you explore the trail, and later export that track as a kml file for external viewing.

Many popular outdoor destinations provide supplemental trail maps that contain relevant information about the area to explore, such as where to find rest areas, the best views, details and warnings about the terrain, etc. When exploring in unpopulated areas, these maps are far more useful than the little to no detail provided from standard non-specific terrain maps. Now you can navigate these trail maps on your handset using Glue Trail, even without a network connection, in any location where your handset can obtain a GPS signal; all that's required is to get the trail map onto your handset as a photographic image and 'Glue it'.

Map Kits

MapKits are an easy way to share your glued trail maps with other users, or to back them up in the event that you uninstall/reinstall Glue Trail or move to another phone. A Map Kit is essentially a self-contained package consisting of a trail map image and its geographically glued coords.

You can wrap your own Map Kit files, using trail maps you've already glued on your handset, and save them as .mpk files, located in your /sdcard/GlueTrail folder. To wrap a Map Kit, long press a trail map in your list and select 'Wrap Map Kit'.

You can also import Map Kit files directly into GlueTrail using the Unwrap feature. Unwrapping a Map Kit will add the map to your list of trail maps and copy the associated trail map image into the /sdcard/GlueTrail/mpkmaps/ folder. To unwrap a Map Kit, select 'Unwrap Map Kit' from the context menu. Glue Trail will search the sdcard and list all .mpk files available; select one to unwrap it.

You can submit Map Kits for posting on this website. Submitted files will go through an approval process before becoming publicly available for download. Submit Map Kits to bitpedal_support@bell.net with subject line 'Map Kit submission'.

Here are the general criteria for approval:
  • Map Kit files must be under 4 MB in size
  • Trail map images must be below 2200x2200
  • Trail map images must be in the public domain (ex. nature parks, travel brochures)
  • ABSOLUTELY NO Google or Yahoo Maps snapshots will be accepted
  • For the benefit of all users, please make every attempt to glue maps accurately
  • Please identify the Country, and Province or State of origin of your submission, so it can be properly categorized
 


 MAP KITS LIST

Gluing a trail map

Before you can navigate your trail map image in real time, Glue Trail needs to know its geographical location. The image will need to be oriented, positioned and scaled properly, using landmarks such as roads, lakes and rivers, land mass boundaries, or any large distinct feature that is common to both your trail map and the standard Google map of the immediate area. This takes practice to perform accurately, and may at first seem time-consuming, but you only need to do it once for any new map. And the glue screen interface makes it simple and fun.

 

Color Adjustment


To help distinguish features while gluing, you can change the color of the trail map to one of the presets and also modify the contrast. These changes are only for the purpose of gluing, and do not modify the original image.

Drag controls

Use the drag mode toggle button to choose the active map. You can drag either the underlying Google map reference, or your trail map image, or drag both simultaneously by locking the Google map reference while in 'Trail map' mode.

Steps to glue a new trail map:

  1. Select 'Glue New' from the options menu. Browse the image list and select the image you will use as your trail map.
  2. On the glue screen, adjust the trail map transparency to invisible (slider fully left) and, making sure you are in Google maps drag mode, move to the general location on the map that corresponds to your trail map image. Zoom in to a reasonable level of detail that is similar to your trail map (if you zoom out too far, you will not be allowed to glue your trail map to these coordinates, while zooming in too close makes it difficult to find landmarks for alignment). Now you are ready to manipulate your trail map image until it overlaps perfectly with the Google map.
  3. Toggle to trail map drag mode (the zoom control will change to brown). Adjust the transparency slider to a level that shows both the underlying map and your trail map. It is recommended that you begin first by rotating the map. If a compass bearing is available then make use of it, by rotating until it points straight up. Be aware that if north already points straight up on your trail map, there is no need to rotate the map as it is already aligned with the underlying Google map (which always points north).
  4. Scale and drag your map until it is approximately at the same size and location as the underlying map. Use major highways, roads, bodies of water, and land mass countours, if available to help you.
  5. Continue making adjustments to rotation, scaling, and location until you have a perfect match with the underlying map. You may need to drag or scale the underlying map some more to get better features on screen. It's also important to drag both maps simultaneously to verify map alignment at different areas.
  6. When satisfied with the results, glue the new map to its geographical location. The glue command is accessed through the context menu.

Using an overlayed KML track as a glue guide

 Load KML
If you have a locally stored kml track of the area you are gluing, you can overlay this track on the map you are attempting to glue. This will make it far easier to align a trail map lacking sufficient landmark details.

Select 'Load KML' from the options menu and choose your kml track. After loading a track, the map will scroll to the geographical location of your track. The track is displayed in bright red, while individual coordinates such as start and end waypoints are displayed as blue dots. Loading a new kml track will override the previously loaded one.

See the next section on how to record a kml track using Glue Trail.

Navigating a trail map


After you have glued a map, it will appear in the list on the main screen. Select the map to begin navigating. You must have satellite GPS enabled on your handset for Glue Trail to eventually get a fix on your location, although there is no need for a network connection; navigating will even work in Airplane mode (verified on Nexus One). Once your position is determined, it will appear as a yellow star on the map. If your location is nowhere near the the trail map, you will only see a grey background.

The facing pointer that appears over your location always points in the direction you are facing with respect to the glued map. Walking in the direction of the facing pointer moves you in the same direction on the map. This is different from your compass bearing, which always points north.
 
 
You Are Here
Will keep you auto-centered on the screen, scrolling the map as you move and explore your surroundings. Auto-centering will disable if you attempt to drag the map in any direction. Tap 'You are Here' to return you to auto-center mode.

Options Menu Commands
 
 
Center On Map
Moves the screen to the map's center, regardless of your physical location. A green arrow will flash briefly, pointing in the direction of your actual location. Be aware that this does not indicate you are close to your map, only the direction from the center of the trail map to yourself. If you are near the map, dragging the map in the direction of the arrow will eventually take you to the yellow star representing your location.

Add/Delete Markers (waypoints)
A marker can be added to any position on the map, including your current GPS location. To add a marker to an arbitrary position on the map, select 'Add Marker'. Drag the marker to your desired position and tap it to select that position. Choose the icon image to use for the marker from the list. If you want to add a marker to your current location, select 'Marker Here' instead; this will only work if your current GPS location has been determined.
 
 
Record Track
Records a continuous track of your trail as you move around to explore. The track is saved when you stop recording. While recording, you can shut down Glue Trail, use other applications, or turn off your screen. The recording service will continue to run in the background until you again start Glue Trail and stop recording.


 
Tracks
Loads a previously recorded track onto your navigate screen. Upon loading, the map will pan to the location of that track. To delete, edit, or export a recorded track, long-press a listed track. You can export a track to kml format, which can viewed on your PC using Google Earth (for example) or any other application that supports this format.

GlueTrail exports tracks to the location /sdcard/GlueTrail.

Track statistics

Go to 'Tracks' from the context menu on the main screen, and select a track to display statistics for that track. Note this behavior is different from selecting the track in Navigate mode, which loads a track rather than displaying its statistics.

Be aware that to reduce storing redundant track points while recording, Glue Trail will only add to the track if you have moved since the last recorded position. If you stand still while recording, no new points will be added. This will result in a track without speed or elevation changes, resulting in stats without graphs.



Deleting a trail map

You can delete an existing glued map by long-pressing the map in the list on the main screen. A box will appear asking for confirmation of your action. Glued maps only save a reference to the original image. Deleting the map will not delete your original image, nor any markers you added in the vicinity of the map.

Accuracy of glued trail maps

Factors that may affect how accurately a glued map tracks your position is dependent on several factors:
  • How closely the map was aligned to its geographical references; you must take care to verify that the map is aligned at all locations, not just a small section.
  • Using photographs taken with the camera not exactly centered on the trail map can skew the image, such that edges are warped or stretched, making it difficult to properly align the entire image to its reference.
  • Using 'novelty' trail maps that are not geographically proportional to reality.
  • Trying to glue a map that doesn't provide enough detail for alignment.

Limitations

Depending on your handset's memory capabilities, using extremely large images for your trail map may cause Glue Trail to run out of memory, resulting in an error upon loading. Before issuing an error, Glue Trail will attempt to load the image by resampling it at a lower detail level. If you do get an out of memory error, you may want to crop the image before using it, either through Android's Gallery browser or with image editing software on your PC. It's recommended that you keep the image dimensions below 2200x2200 to avoid downsampling and loss of detail when loaded into Glue Trail.

Converting PDF trail maps

Many trail maps are available only in PDF format. As Glue Trail does not load this format, you will need to find a way to convert your PDF into a standard image format before using it. You may want to try one of these PC-based pdf converters:

SoftInterface
Zamzar
Neevia
ConvertPdfToImage