[Proj] cs2cs for datum conversion and the "towgs84" parameter

[Oscar van Vlijmen]

> From: "Hyer, Dr. Edward \(Post Doc\)" <edward.hyer-nrlmry.navy.mil>

> 3) This guy's doctoral dissertation (in Portuguese)
> (http://www.teses.usp.br/teses/disponiveis/3/3138/tde-06122002-115813/publico/
> 03capitulo02.pdf) claims that SAD69 to WGS84 is nothing but a shift of -66.87
> meters X, +4.37 meters Y, -38.52 meters Z. He also states that this is by
> Presidential Decree. Is this like the "pi=3" thing here in the States?

You can find the decree at:
<http://www.ibge.gov.br/home/geociencias/geodesia/default_normas.shtm?c=14>
Or follow from the main page the menu Geociências > Geodésia, then
Documentação > Especificações e Normas.
It's a file "rpr-2389.pdf" with:
"RESOLUÇÃO No 23, DE 21 DE FEVEREIRO DE 1989"