Elevation Readings

bobpbx

Piney
Staff member
Oct 25, 2002
14,323
4,444
Pines; Bamber area
Boyd, I uploaded waypoints so I can use your elevation feature and capture the elevation of each. Using my GPS is not acceptable, as I can tell some of the numbers are way off. I plan to just center the crosshairs on each waypoint and then type it into an excel file I'll have open. Is the base of the flag pole correct for capturing elevation, as shown?

1664806753577.png
 

Boyd

Administrator
Staff member
Site Administrator
Jul 31, 2004
9,571
2,818
Ben's Branch, Stephen Creek
No, each waypoint is 48x48 pixels and the center is in the middle of that square. I won't bore you with the technical issues, but it's a bit confusing with the flag icon. This is the same with the flag icon on Garmin devices and software, from what I recall.

You could change the default symbol to a dot to be more accurate, then re-import your Garmin waypoints. To change the default, edit any waypoint and click on the icon. Click the gear at the top left of that window. Now you can choose your default symbol.

BTW, if you click on each waypoint you want to change, you can use the button to update the elevation, then save it. When finished, you could export the waypoints as a boydsmaps (.txt) file. This can be directly imported into Excel. But maybe that wouldn't be compatible with the system you've already developed?

The other thing to understand is that the LIDAR elevation data is equivalent to zoom level 17 (1.2 meters), so zooming in farther won't give you more accurate readings. If these are waypoints you created on a Garmin GPS, they are typically only accurate with 5 meters so zooming way in isn't likely to help much. There are going to be quite a few elevation readings within that 5-meter circle of probability.
 

Boyd

Administrator
Staff member
Site Administrator
Jul 31, 2004
9,571
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Ben's Branch, Stephen Creek
I said: You could change the default symbol to a dot to be more accurate, then re-import your Garmin waypoints. To change the default, edit any waypoint and click on the icon. Click the gear at the top left of that window. Now you can choose your default symbol.

This may not work, it's only for waypoint files that don't already have symbols defined or if you used symbols that I don't support. If you already have flags in your file, they should be imported like that.
 

bobpbx

Piney
Staff member
Oct 25, 2002
14,323
4,444
Pines; Bamber area
Thank you for the information. Since the GPS is only accurate to about 3-5 meters, me trying to better what I have now to a finite degree by tweaking its location is non-productive, especially when you consider that the entire 7400 acres only has an elevation total range of about 80 feet....so moving the waypoint a small amount might change it a couple feet and I'm not concerned about that.
So, just to be consistent, could I just place the cross somewhere else than the pole base each time, like with the horizontal line aligned to the base of the flag like this?


1664821085620.png
 
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