[PROJ] Proper projection system for Aruba

[Jelmer Baas]

Hello,

I'm trying to convert coordinates from what seems to be a custom projection system in Aruba, without much luck.

In their drawings, they have data around 3000, 18000. Whatever existing projection system I use (EPSG 24819, EPSG 32619), I end up at a completely different location.

For example:
echo 2936 18088 | cs2cs +proj=utm +zone=19 +ellps=intl +towgs84=-216.408,279.243,-203.231,-8.56912,40.8756,-12.5593,15.8909 +units=m +to +proj=webmerc +datum=WGS84
-8178296.58     17850.76 22.52

echo 2936 18088 | cs2cs +proj=utm +ellps=intl +towgs84=-216.408,279.243,-203.231,-8.56912,40.8756,-12.5593,15.8909 +units=m +to +proj=webmerc +datum=WGS84
-830835.88      16729.91 101.08

This is way outside the expected area. In 3857, the data should be somewhere between
-7800000, 1417000
-7777000, 1393000

I do have the attached ".gtf" files, but I'm unsure how to apply this in proj. Is the above string correct? What am I missing?

Any help would be greatly appreciated.

Regards,
Jelmer Baas

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