Balto/Interactive Map

Interactive Map

The Interactive Map is a powerful tool for visualizing search areas, planning grid searches, dividing areas into sectors, and analyzing trailing dog tracks. It supports importing geographic files from CalTopo and other mapping applications.

Here is a video demonstrating how to load up geo information from CalTopo and generate search paths and sectors:
Watch the Balto tutorial video on YouTube

Opening the Map

Tap the map icon in the toolbar to slide the map view in from the side. The map displays your current GPS position as a blue pulsing marker, with an accuracy circle and heading indicator. Tap the map icon again to slide the map view away.

Importing a Geo File

Balto supports importing GPX and GeoJSON files from other applications.

From CalTopo

1. Open CalTopo on your device
2. Select the map object you want to share (polygon, line, or waypoint)
3. Tap the share button
4. Choose "Balto" from the share sheet
5. The file will be imported and displayed on the map

From Other Apps

Any app that can share GPX or GeoJSON files via the system share sheet will work the same way. Tap the share button in the source app, then select Balto from the list.

After import, the map will automatically center and zoom to show all imported features. The status bar at the top of the map shows what was imported (number of polygons, lines, and points).

Generating a Grid Search Path

A grid search path with direction arrows

For area searches, Balto can generate a serpentine grid search path within an imported polygon.

1. Import a polygon defining your search area
2. Tap the polygon on the map to select it (it will highlight)
3. Tap the grid search button in the zoom column on the right
4. The Grid Search panel will appear at the bottom of the map

In the Grid Search panel:

Wind Direction slider

Set the direction the wind is blowing FROM. The grid path will start at the downwind corner of the area so the dog works into the wind. Tap the compass rose buttons (N, NE, E, SE, S, SW, W, NW) for quick wind direction selection.

Wind Direction button

Press and hold the compass icon while pointing your phone into the wind to set the Wind Direction slider.

Spacing slider

Set the distance between parallel lanes of the grid. Smaller spacing gives more thorough coverage but takes longer to execute. The slider range is from 10 metres to 200 metres.

Reverse direction

Tap to reverse the path direction if needed.

Chamfer corners

Tap to add rounded transitions at the lane endpoints instead of sharp turns.

Direction arrows appear at the midpoint of each segment showing which way to walk. Arrow size can be adjusted using the arrow size slider.

Exporting a Grid Search

To save the grid search for use in another application:

1. Generate the grid search as described above
2. Tap the export button in the panel
3. Choose where to save or share the GPX file

The exported GPX file can be loaded into Garmin devices, CalTopo, Google Earth, or other GPS applications.

Generating Sectors

Sectors generated over a search area

For evidence searches or systematic area coverage, Balto can subdivide an imported polygon into a grid of square sectors with unique labels.

1. Import a polygon defining the area
2. Tap the polygon on the map to select it
3. Tap the sector generator button in the zoom column
4. The Sector Generator panel will appear

In the Sector Generator panel:

Sector size slider

Set the area of each sector in acres. Sectors are square and rotated together to fit the polygon.

Rotation slider

Set the orientation of the sector grid. Sectors are labeled with column letters and row numbers (A1, A2, B1, B2, etc.) that follow the rotation.

Each sector is drawn with a unique color from a palette of 12 colors that cycle through the grid for easy visual distinction.

Exporting Sectors

To save the sectors for use in another application:

1. Generate the sectors as described above
2. Tap the export button in the panel
3. Choose GPX or GeoJSON format
4. Choose where to save or share the file

GPX files include the Garmin DisplayColor extension so sector colors are preserved in compatible applications. GeoJSON files use the stroke and fill properties recognized by CalTopo and other web mapping tools.

Track Analysis

Track analysis with deviation coloring

For trailing dog training, Balto can compare the dog's GPS track to the subject's track to compute deviation statistics.

Here's a video tutorial:
Watch the Balto tutorial video on YouTube

1. Import a GPX file containing both the subject's track and the dog's track
2. Tap the track analysis button in the zoom column
3. The Track Analysis panel will appear

In the Track Analysis panel:

1. Select the subject's track from the first combo box
2. Select the dog's track from the second combo box
3. The analysis runs automatically when both tracks are selected

The dog's track is colored based on its deviation from the subject's track at each point:

Green

Less than 5 metres deviation

Amber

5 to 15 metres deviation

Red

More than 15 metres deviation

The panel displays maximum and average deviation in metres.

Geofencing

When a polygon is loaded, you can enable geofencing to receive an audible warning if you walk outside the search area.

1. Import a polygon defining the search area
2. In the status bar at the top of the map, toggle the Geofence switch to On
3. Balto will speak "Warning, you are outside the search area" if you exit the polygon

Geofencing continues to work when Balto is running in the background, allowing you to put your phone in your pocket while working.

Clearing the Map

To remove all imported data from the map, tap the Clear button in the status bar at the top of the map view.