Now that we learned the basics of positioning, latitudes and longitudes let us take a looks at map reading next
In this session we will get familiar with (satellite) map reading to identify and create off road trails not seen in regular Google route Maps. Initial focus is on the plains near the city, later on we will get familiar with terrain or topography maps to navigate in the mountains
Type: home assignment
Date: Tuesday 16 Feb
Deadline: Friday 20 Feb
Duration: 1-2 hours
Submit one set of answers per team
All team members to participate & understand
Let us try to identify an off road trail connecting two villages near following locations:
Search the above latitude, longitudes in Google Earth to find both villages on the map:
At a high level you can just see barren land, greenery, dry lakes in between both villages
However if you zoom in sufficiently you can identify an off road trail which runs through the forest and connects to the nearby main road:
Use the Path tool in Google Earth to trace this trail with your mouse:
(Try this yourself !)
Under Style/Color please change color to yellow and width to 3 so the trail is clearly visible
Congrats! You have now created your first off road trail.
Loading Trails in Phone
Let's see how to download this trail in your Smartphone and use it for field navigation between both villages
Right click on the trail you just created and choose "Save Place As"
Save it as type "KML" (not KMZ) and give it a name - e.g. "MyFirstTrail.kml"
You can open the resulting KML file on your laptop in any text editor and see that it is nothing but a series of connected points (lat, lon) that make up a line/trail:
A convenient way to copy this trail onto your phone is through email
Attach the KML file to a new mail and send to yourself: (using Gmail here)
On your phone open the mail and save the trail on your phone
Install Oruxmaps (or any other map/GPS app) on your Smartphone to view maps and trails
Open Oruxmaps on your phone and:
- Click on the Map symbol, choose Switch map and select "OpenStreetMap Mapnik"
- Click on the Route symbol, choose Load KML/GPX file and go to folder where you downloaded the KML file
(On Samsung phones: Root-Storage-Sdcard0-Download)
Select "MyFirstTrail.kml" to load the trail you just created in Google Earth:
After loading press OK and the trail will be displayed on the OpenStreetsMap base map:
You are now ready to go into the field and explore / navigate your newly identified off road trail using your Smartphone !
Do it yourself - Home Assignment #2
Practice makes Perfect ! Let's try this again now completely by yourself:
Question 1 -
Search Google Earth for "Nanmangalam Reserved Forest" located near Medavakkam, Chennai
Create a trail that runs through this forest from North to South connecting to the main roads on either side
Load this trail in your Smartphone and take a screenshot showing the trail in Oruxmaps
Upload the image in an online album (e.g. Picasa)
(use this album to submit all images in future assignments)
(Example link over here)
After successfully completing assignments 1 & 2 you are now ready for field navigation practice using your Smartphone in the third assignment! Stay tuned!
To already prepare yourself: get outside, switch on your phone GPS, open Oruxmaps, switch on GPS tracking, go for a walk in your neighborhood and watch your screen!