Please Sign In

New To Sportsman Network?

TO; 10asee

I have plotted the position as Degees, Minutes, seconds and hundredths of seconds. DDD,MM,
using WGS 84 Datum.
As you can see it is at the mouth of the canal.

Try checking what DATUM is being used by the Google maps you used.

Some points about the errors:
Many aerial photo maps are NOT ORTHO corrected. The map that I used is an ortho corrected one.
I can’t say if the Google maps are corrected, I suspect that they area not corrected maps.

Check the DATUM that you were using as compared to the DATUM used by Google. Different datum settings could amount for the distances you describe.

Check the position format that you are using. Trying to enter a different format than the unit was set up to use will cause the inaccuracies. you describe.

Check if the iPhone has access to the WAAS differential system. If it does not and your GPS unit does have it, your unit will be much more accurate, usually within 3 meters. Without the WAAS feature the accuracy will be 60+ meters.

Note the included photo of my plot.

Captain Paul

Latest Columns