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Triangulation

Former Member
Former Member
I want to know if there is way to do a triangulation to project a way point. I know that my GPSmap 62S can project a waypoint. However to do this you need a heading and a known distance. I have been doing Search And Rescue in the mountains for years and have yet to find an instance where I could get a heading and a distance. However using old school military training and a compass and map can get a bearing from two or more know locations and could draw out my lines and where they cross is a probable location. I know that when you use Base camp measuring tool you can draw a line from a known positions and it gives you a bearing. But if you try to move to a second location and repeat the process the first line goes away.
We use UTM coordinates on our GPS and can transpose data back and forth when needed but it would be so much easier if you could do it from base camp. I mean we are in the age of the computer why do I still need to do it old school.

Thanks.
James
  • Welcome to the forum, James, and thank you for your service to your fellow man. Mountain search & rescue has to be a demanding occupation, or hobby, and I honor you for doing it. It's the least I can do to spend some time thinking about your question.
     
    I doubt there is a direct way. And you are correct that if you try to establish a second bearing line with the measure tool, the first one goes away. Also if you select any other tools using the mouse, any set bearing line goes away. However, at least using the PC BaseCamp (I'm using 4.1.2 in case it makes a difference), you can zoom and pan the map view using the arrow and +/- keys and a bearing line remains. Therefore, how about:
     
    1. Create waypoints at the locations from which you have bearings, for a simple example assume two points, say A and B.
    2. Using the measure tool, click at the first waypoint, then pull away from that point and create a bearing line at the desired bearing that is long enough to be crossed by the other bearing line. Click to lock that line, then press escape. the bearing line will remain displayed.
    3. Using the zoom (+) or (alt +) and the pan (arrow key or ctrl-arrow key) adjust the screen so that the end of the bearing line shows at the maximum zoom level (80 ft).
    4. Move the measure pointer so the end of the pointer is on the end of the bearing line.
    5. Press the "W" key which should erase the bearing line but change the pointer to the waypoint tool, with the pointer still where the end of the bearing line was. Click to place a waypoint there.
    6. Create a route from A to the waypoint just created. Go into the route properties and change the activity profile to Direct if it's not already. You will now have a straight line from A in the direction dictated by your suspected bearing from A.
    7. Change back to the measurement tool, click on waypoint B to make it the starting point for the second bearing line, run the pointer along the route line created above, until it indicates the suspected bearing from point B. When you have the correct bearing and are on the route line, again press the "W" key and drop a waypoint there. This will then be the point where the two bearing lines cross, and the lat/long data can be easily read from that waypoint.
     
    You may have to make some adjustments in this procedure, I just tried it briefly, but you get the idea. I hope it might work for you!
  • Former Member
    0 Former Member over 11 years ago
    Hello and thank you greatly for the work around on this. I have fought this for the past couple of years and I knew there had to be away. I guess part of my problem is I am old fashion and I am not sure I have warmed up to this computer enhanced world or not. In fact the only thing that I do like that is electronic is my GPS. And I did go through some issues as to finding the right one and worked with several. And I ended up with the GPSmaps 62s and I feel I made a good choice. And it has served me well since they first come out I live in Oklahoma where I am heading up the training and setup of a SAR team and mostly mounted on horseback. So to keep up to speed and in practice I head to the Rockies every year and volunteer or just spend weeks working on techniques. And we always end up going back to old school to accomplish this task.
    So I worked through the steps you outlined and I think it will work and that is all that matters. However I do not know how to get this idea to the folks there at Garmin Base Camp but realizing that they make a valuable tool that is not just used for finding hunting spots or geocaching but sometimes saving lives. This would be a simple tool to be added that could make a major difference in accuracy and speed.
    I have tried three times now to contact the support folks and I get my confirmation but that is has far as it goes. But this is far to importation to just give up on. And I think that if someone would or could explain this to the folks there at makes it happen they could see the benefits.
    But I thank you and I am looking forward to passing this on to all the others and I can assure you that you have helped more than just myself. Thank you for your time and effort.
    Thanks.

    James Gardner
  • This is something you could do with MapSource with either a direct route or a track, your choice. The information bar at the bottom should give you bearing and distance along with Lat/Lon. You could then transfer the tracks/routes to BaseCamp with a copy and paste – no need to import/export files.

    Displaying distance and bearing on the bottom bar along with Lat/Lon is something that the BaseCamp programmers should consider adding. Also, distances should be shown to a consistent precision. For example if you display feet for short distances, then miles should be displayed to 0.0001 miles
  • Former Member
    0 Former Member over 11 years ago
    Thank you I will check that out as well.

    James
  • Former Member
    0 Former Member over 11 years ago
    It works in BaseCamp 4.2.3 and in MapSource 6.16.3 as described.
    In MapSource after placing a waypoint, you need to close the Waypoint window.
  • Hi James,

    Perhaps you were able to figure this out from the above posts but sometimes it's worthwhile to spell it out in steps (works best for my brain). This is using the Track Drawing tool in Mapsource 6.16.3 (the last version released).

    1. In Mapsource click on the Waypoint Tool (little flag in the toolbar) or in the menu go Tools > Waypoint.

    2. Use the waypoint tool to create waypoints for the two known locations.

    3. Right-click on the toolbar section and turn on the "Track Edit" toolbar if it's not already there.

    4. Click on the Track Draw Tool or in the menu Tools > Track Draw.

    5. Click to start a track line at one of the waypoints. When you do this, just click and release to lock the starting point in place so that when you move the mouse you will get a straight line that will stay a straight line as you move the mouse.

    6. Drag the tool far enough to create a visible line.

    7. Look at the information bar at the bottom of the Mapsource window. You'll see the coordinates, the distance from the start of the line to the present mouse location and the bearing of the line.

    8. Swing the line to approximately the bearing you want, pull the line way out beyond any place the triangulate location might be, move the mouse to fine tune the bearing reading and click the mouse to lay the end point of the track line.

    9. Hit the ESC key to end that drawing. The line will stay put for you.

    10. Repeat the process for the second waypoint and bearing. (Remember to hit the ESC key to end the second track, leaving the line in place and freeing the mouse for the next step.)

    11. Move the mouse cursor to the point where the lines intersect and look at the information bar to see the coordinates. Switch back to the Waypoint tool to make a waypoint there if that's helpful.

    It seems a really simple process in Mapsource. Pretty much the same method you would use with a paper map, pencil and ruler.

    I did not try it in Basecamp to see if the track drawing tool works as simply there. Sometimes things are as easy or easier in Basecamp but I still use Mapsource by preference so it's what I'm used to for stuff like this that's quick and easy. I am not a patient person so I also don't have the patience to wait for Basecamp to load if I just want to do something trivial like this, especially on my little notebook when I'm away from the desktop. Mapsource is quick to load even on low horsepower machines.

    I hope this helps and I apologize to those who already posted who were basically saying the same thing. I just find that sometimes a step-by-step helps me get there a little easier. Probably my OCD rearing it's head. ;)

    ...ken...
  • James, I noticed that you are on a learning curve so I'll expand a bit on point 2 above to create the two waypoints.

    This assumes you have coordinates for the two known locations.

    1. Select the Waypoint tool as above.

    2. Move the mouse over the map until you see the desired coordinates for one of the waypoints in the information bar at the bottom of the Mapsource window.

    3. Click the mouse on that spot. This will open the Waypoint Properties window.

    4. Change the name of the waypoint if you wish.

    5. Change the symbol to something that's easy to see on the map. I like one of the flags but that's just me.

    6. Click OK to save the new waypoint and close the waypoint properties window.

    7. Repeat for the other waypoint.

    Sorry if I'm restating the obvious above but if you haven't used Mapsource before, or in a very long time, some of that stuff is not obvious.

    ...ken...
  • Okay, I tried it in Basecamp and you can't do it. Creating the waypoints is much easier/quicker in Basecamp. But as was mentioned above by BTLAAKE you can't get the distance and bearing displays in Basecamp. Sorry that I didn't catch the significance of that when I read it the first time. That display in the information bar in Mapsource makes it such a simple process.

    ...ken...
  • Former Member
    0 Former Member over 11 years ago
    Thank all of you for the input I worked through it as C14_Rider suggested and it worked fine. I went out in the country this past weekend and put it to the test and it worked with out a hitch. So I am on my way I just have to use a a good compass to get the bearing because the one on the GPS leaves you guessing. I always have my old military lensatic compass and a map.
    However I am sure until there is a change in the software to make this more efficient this work around will do the job. I just have to get this working with all the rest of the unit I work with.

    Have a great day.

    James
  • Former Member
    0 Former Member over 11 years ago
    Thanks

    Well thanks for that tip, I did not realize that so that is now a priority. However I do not use the compass on the gps to get my bearings to a target area. Not saying the GPS compass is not accurate it is just not broken down to a fine enough increment and pretty hard to get a good sighting with it. As were using my Military Lensatic compass it has an aiming system on it and is finer in detail.
    Thanks again

    James