I bought a Simrad
Go and want a chart for a large lake in Alaska
I purchased the Alaska
Lakes chart and it less detail for a 60 mile long lake than a typical desk top globe does. I got my money
I did a bunch of research
and didn't find much info, but was able to find some guides on creating your own charts
downloading google satellite images
with sas.planet and insight map creator.
The chart I am trying to make is roughly 100km(~65 miles) by 100km, of which my boat
is roughly in the center sitting on a trailer
in my yard.
After a few failed attempts I was able to get the chart to display on my Simrad
, I had to change the Atlas version to 10 in Insight Map Maker.
So at this point I can make different charts(google, bing, arcgis, satellite
, road, etc....) with different names all on the same card and choose which one I want to use in the plotter. However, they are all roughly off by 200m(~700ft) which I feel is a pretty significant error.
I did a test where I made a very small chart of just my village, and it seemed much more accurate, probably within a few feet.
I don't know if my problem is in the charts
that sas.planet downloads (I doubt it since they all have the same error), something wrong with the way I download them, something wrong with the way I save them from sas.planet with the .kml file, something wrong with the way insight map creator translates the .kml file into a .jgw file, something wrong with my settings in map creator, something wrong with the gps
in my plotter (I dont think so since it did display close on a much smaller chart)....... I'm at a loss.
I suspect my problem is some sort of rounding error, but I don't know.... I am kind of a loss at what to try next.....
Has anyone run into this issue before or have any ideas on how I should go about troubleshooting my process?