Garmin eTrex 10 User manual

MLN Survey Protocol
Guidelines for Using a GPS on MLN Surveys
1. Garmin Etrex 10 GPS Unit- Overview
The Garmin Etrex 10 unit is commonly used. Other handheld GPS units have near identical
functionality, although screen layouts and key buttons differ between units.
[NOTE: If no GPS unit is available an alternative is to use a smartphone. The free apps –
GPS Status & Toolbar or GPS Essentials are recommended].
Images from Garmin

MLN Survey Protocol
2. Notes on basic GPS use and functions
What can you use a GPS for?
• Measuring location (latitude, longitude –elevation is also included) –this is termed
Waypoints and is the most important function
Can I use my GPS anywhere?
• GPS units can work anywhere in the world, in any weather, 24 hours a day
• The basic units described here will give up to about 4-5 meters horizontal accuracy
and 15-20 meters vertical accuracy
• GPS units will not work inside buildings
• If you use a GPS next tall buildings or in dense forest, you may get problems in
receiving the signal
Moving to a new location hundreds of kilometers away will usually result in an
initial delay in getting a fix on satellite signals. A few minutes wait may be required
in new locations.
What is the best way to use a GPS?
• Make sure the unit has two AA batteries installed –Alkaline are best
• Always write down location coordinates, elevation–even if you plan to download
data
• Always use a GPS to record location data!
Is there anything else I should remember?
• Do not block the antenna (located just above the word “Etrex”on the front of Garmin
GPS) with your fingers or head
• Always carry an extra set of two AA Alkaline batteries

MLN Survey Protocol
3. Setting up your GPS for use (first use only)
Settings - This only needs to be done ONCE –upon receipt of GPS units, prior to use in
field survey. After settings are complete, NO further changes should be made. Properly
setting up your GPS helps to ensure that standard GPS settings are used in every country.
Every effort is made to standardize GPS units before distribution.
Standard Settings Procedure
This can be done indoors, no satellite signal is needed
1. Switch on GPS by pressing Power key
2. Press Back key until the Main Menu screen appears
3. Use the Thumb Stick to select Setup
4. Press down on the Thumb Stick to open the Setup Menu
5. Use the Thumb Stick to select Units. Press down on the Thumb Stick to open the
Units Menu. The Units option contains the key settings that you should check /
change. Set Distance and Speed to Metric. Set Elevation to Meters
6. Use the Back key to return to main menu. Use the Thumb Stick to select Position
Format.
The required Position Format settings are:
Position Format: Hddd.dddddº [this means that latitude / longitude coordinates are
given in decimal degrees]
Map Datum: WGS 84
Map Spheroid: WGS 84
7. Use the Back key to return to main menu.

MLN Survey Protocol
4. Using a GPS for field survey
1. Turning on the GPS and getting a satellite signal
1. At the field location. Switch on GPS unit by pressing the Power button
2. Press the Back button until the Satellite page is visible
3. Wait for 2-3 minutes for the GPS to get a location fix using the satellites overhead.
4. O n c e a f i x h a s b e e n o b t a i n e d , s a t e l l i t e s y m b o l s a n d s i g n a l
s t r e n g t h b a r s w i l l t u r n b l a c k . Once signals from at least 4 satellites have
been received, Latitude and Longitude data (and GPS accuracy) will be displayed. Once
latitude and longitude are displayed and accuracy is 10m or less, you can now record the
location.
Note 1:
The first time you use a GPS in a completely new region it can take up to 5+
minutes to receive satellite signals. After initial use, signal reception will be much
faster –about a minute or less.
The more satellites you receive signals from the more accurate will be the location.
So it is worth waiting a short time before recording a location. However, the
maximum accuracy possible with these units is +/- 4 or 5 meters. Anything less
than 10 meters is good enough.

MLN Survey Protocol
2. Recording and storing a location –“Marking a Waypoint”
There are two ways to do this:
Option A: Via the Enter Key
1. Press and hold the Thumbstick. This will make the
Waypoint page appear –showing a 3 digit waypoint
number, latitude, longitude, elevation
2. Record the Latitude (N or S), Longitude (E or W)
and elevation data on the survey form
3. Select Done, and press ThumbStick to record and
save the waypoint
Option B: Via the Main Menu
1. Press the Back key until the Main Menu
appears.
2. Use ThumbStick to select Mark Waypoint
3. Press Enter key to open Mark Waypoint page
4. Record the Latitude (N or S), Longitude
(E or W) and elevation data on the survey form
5. Select Done, and press ThumbStick to record and
save the waypoint
3. Turning off the GPS
1. After recording the location (“Marking the Waypoint”), switch off GPS –press and hold
Power key
2. Complete the MLN Survey Form and sampling
3. Move to next survey location