[Proj] Google Earth Accuracy

[Jan Hartmann]

Irwin Scollar wrote:
 >
 > Are the points in that list available on the Web without charge?  If
 > so, please provide a link.

https://rdinfo.kadaster.nl/rd/kernnet_meter.xls:  core points (425), 
mostly stones
http://www.geogames.nl/meetpunten/data/RDmeetpunten060506.zip: all 
points (5763, including towers etc)

The lists contain only RD coordinates. The official conversion program 
can be downloaded from http://www.rdnap.nl/download/setup%20cc41.exe.
It converts to and from WGS84, and also to and from Belgian Lambert and 
German Gauss-Krüger coordinates. The official German conversion program 
from the "Bundesamt für Kartographie und Geodäsie" is hidden at 
https://upd.geodatenzentrum.de/geodaten/gdz_rahmen.gdz_div?gdz_spr=eng&gdz_akt_zeile=3&gdz_anz_zeile=6&gdz_user_id=130820075408

 > There are 16 sources of trig point data, one from each of the mapping
 > agencies of the German "Länder". None of these were free of charge the
 > last time I looked, so I haven't tested them.

Well, our cadastral and topographical agencies are not *very* 
forthcoming with their data, but they made these points available for 
benchmark hunters, people who try to find these points with their GPS's 
and photograph them (http://www.geogames.nl/meetpunten/). Seems to be 
very popular in the US (http://www.geocaching.com/mark/  and 
http://forums.groundspeak.com/GC/index.php?showforum=10)

Jan