BUTTONS AND THEIR FUNCTIONS:
Right Side (2 Buttons)-
· POWER is the bottom button. Press and hold for 1 second to turn unit
on. Press and hold for 2 seconds to turn unit off.
· PAGE is the top button. It navigates between each of the four main
screens (Satellite, Route, Compass, and Menu) and acts like a computer's Escape
key to get out of all sub-menus.
Left Side (3 Buttons)-
· Top button is UP, middle button is DOWN - used to move between options
within any menu.
· ENTER is the bottom button. Used to select menu options and mark waypoints.
BECOME FAMILIAR WITH THE eTrex PAGES:
Be sure you are standing in a reasonably open area so the unit can receive satellite
signals. Press the POWER button to turn on your unit. Before doing anything
else, the unit must tell you it has located a number of satellites and displays
a "Ready to Navigate" message.
You are currently on the Satellite page…it tells you which satellites the
unit is using and how accurate your readings are. In an open area, the unit
will be accurate to within about 25 feet. NOTE - this is an estimated accuracy,
not necessarily what you get.
Press the PAGE button to move on to the Route page. When you begin walking,
the stick figure will begin moving, leaving a black trail behind. If you cannot
see this trail, press DOWN as many times as needed (this adjusts the scale of
the image).
Press PAGE again and you reach the Compass page. Strangely enough, it's a picture
of a compass telling you which direction you are walking.
Press PAGE once more and you arrive at the Menu page. Here you can keep track
of routes, tracks, and waypoints. You can also tinker with the settings from
this menu.
CHECK YOUR SETTINGS:
Now that you've seen all of the pages and you're on the Menu page, it's time
to check the unit's settings. Move to the System sub-menu by pressing UP (the
cursor wraps around to the bottom) and press ENTER. Navigate to Units and press
ENTER.
There are five settings you can manipulate here - but we'll only deal with two
of them for now. First, go to Coordinates and press ENTER. Here you can set
the coordinate system (projection) to UTM, Lat/Long, or some wild system. Highlight
your desired system and press ENTER.
Next, we need to pick our datum (the mathematical model of the Earth used to
calculate position). Highlight Datum and press ENTER. Now pay attention - what
you do next could throw off your position by hundreds of meters!
Look at the bottom margin of the map. If you are trying to locate points off
an older USGS topographic map, select NAD27 CONUS (North American Datum of 1927)
and press ENTER. Do not use the default for classwork - the default setting
WGS84 (World Geodetic System) is most applicable to international applications.
MARK AND SAVE YOUR POINTS:
You're almost ready to save points for later. Press PAGE until you return to
the Menu page. Press UP to get to the Waypoint sub-menu and press ENTER. If
any numbers are displayed in the right-hand column, these are previous waypoints
that need to be deleted. Press UP once to highlight Delete All (at the bottom
of the screen), press ENTER, highlight Yes to confirm your deletion and press
ENTER again. Did it work?
Now return to the Menu page by pressing the PAGE button. Now walk to whatever
point you want to mark for later. To keep yourself amused on the way to the
point, cycle through the main pages to follow your progress.
When you reach your point, highlight Mark on the Menu page and press ENTER.
An image of a man about to drive a flag into the ground should appear along
with the coordinates of where you're standing. Press ENTER to save these coordinates
in the Waypoint log. Repeat this procedure until you've collected all of your
points.
DOWNLOADING AND CONVERTING eTrex WAYPOINTS WITH GARtrip:
GARtrip, a shareware program developed in Germany in 1997, is designed to convert
waypoint, route, and track information from Garmin GPS units to a text-only
format readable by Microsoft Excel. We will eventually export the data from
Excel to ArcGIS, but that's for later! Note: GARtrip is only loaded on one GIS
lab computer - CWU PC2, located in the back room of the GIS lab (near the windows).
Login, connect the cable to the GPS receiver, and turn the receiver on.
Start GARtrip by double clicking on the desktop icon. A window will pop up - "open waypoint file" - hit cancel.
MAKE SURE that the "Grid Coordinates with dot (km)" option is NOT checked (under the System menu). Otherwise your x,y coordinates will be wrong! (you want your data in meters)
Click on Garmin > read waypoints. At this point, all your point files should show up in the proper window. If you feel like it, set the coordinates, format, and datum to whatever you had the receiver set to log. However, I don't think this is important.
There are some cool options in the software, including basic mapping capabilities. Play if you like.
Click on File > save as and save your file as a tab delimited GARtrip text *.txt file. (to your zip/floppy) (waypoints only)
quit out of GARtrip.
FROM TEXT TO EXCEL:
Okay, the hard part is over! We want the newly-created text file to convert
into a database fileso we can use it in ArcGIS. To do this, we must get the
information into a .dbf format. There are a few options here, mostly annoying.
Open Excel. Click on file > open, set file types to all files, open your text file. A import wizard will pop up - just hit finish, the defaults work just fine. Now - some quick edits - you need to ensure that row 1 contains the column header names. NOT row two, etc. Row One. Next - no blank rows until you hit the end of your data. Also, ensure every column of data has a header name. You can delete any of the columns you like except the easting and northings. Like rows, ensure all your data starts in column 1 with no blank columns inbetween data. (note - if you were foolish enough to save data in Lat/Long, you have some serious editing to do - or head back to gartrip. No text values are allowed (N/S/E/W) as part of the data - and longitude values are negative in the US.)
Now for the pain-in-the-butt part. First, if it is available, use Excel 2003 - it has an export to .dbf option (dbase 4). Highlight your data and headings. Save the file as a dbase IV (.dbf) format file. Say 'yes' when Excel asks about saving in this format. Now, quit out of excel - it will ask if you want to save the file - say 'yes', overwrite the one you made earlier (same file name). And yes to anything else. Skip any of these steps (highlight, save, quit, save) and it won't work. Don't ask me why. Keep the original downloaded coordinates text file as a backup. Now, if you only have Excel 2007, you must do more (because save as .dbf is no longer an option). First, save your file as an excel file. Then open Access 2007 and do the following: click on the doodad in the upper left corner and select 'open' - navigate to your excel file and open it. Select the external data tab, then goto the export section. Click on 'more' and select dbase file. Select dbase IV as your option.
Either way, you should now have a .dbf file.
FROM EXCEL TO ArcGIS:
Open ArcMap with a new, empty map.
Click on Tools>add x,y data, select your .dbf file. Pick easting as your x field and northing as your y field. If your colunm headings aren't visible, you hosed up your export to .dbf in Excel. Go back and do it again. Click on the edit button and enter the coordinate system information - this will be whatever you set the receiver to. For example, if working in Ellensburg using UTM coordinates in the NAD27 datum, you would: click edit, click select, click projected coordinated systems>UTM>nad27>UTM zone 10. Add it, then a couple of OKs and you data will plot.
Your data is now in, but not really as a GIS file. Thus, one more step. Right click on the filename (to the left side of the ArcMap window) and select data>export data. Type in a filename and location you like and save that puppy as a shapefile.
Now you have a projected shapefile that is ready to rock and roll.