Generating a KML for US

[Olly Betts]

On Tue, Sep 10, 2019 at 05:52:44PM -0400, Richard Knapp wrote:
> *cs out EPSG:32136
> *cs EPSG:32136
> *fix B001.WC0 794682.45 3077751.87 1462.31
> 
> but it put the cave in Hudson Bay! I know it is something to do with
> the output command but I don’t know how to even ask the correct
> question.

The "*cs out" command says what coordinate system you want to be used
for processing the data and writing the .3d file.  It needs to be a
metric grid with X East, Y North and Z up, and to be valid for the
coordinate range of the data you're processing.

A "*cs" (without "out") command specifies the coordinate system of fixed
points which follow (and you can change it so fixed points can be
specified in different coordinate systems).

> The cave is located near Johnson City, TN so I think the
> EPSG:32136 is correct.

While EPSG:32136 covers that area (and indeed the whole of the US), many
other coordinate systems do too, and you need to specify the one which
your coordinates are actually in because the same numbers represent
different locations in different coordinates systems.

In EPSG:32136 Johnson City, TN is ~ 927400, 225700 so clearly your
coordinates aren't in EPSG:32136.

It looks to me like they might be in EPSG:3662, but that you've switched
the Northing and Easting - swapping them that comes out NE of Johnson
City:

https://epsg.io/map#srs=3662&x=3077752&y=794682&z=13

I'd check with whoever/wherever you got them from though.

Cheers,
    Olly