Benchmark Hunt In The Netherlands

[Prof. Y. Lupardi]

Yes, after some time we managed to setup a benchmark hunt for our small country with only 5000+ marks to visit.

It is done in cooperation with our Geographic Institute (Kadaster, Rijksdriehoeksmeting).

We hunt using the local grid coordinates (Dutch Grid off course) and make photographs of the object in question and the surroundings.

The Survey Service is very glad to have information concerning their marks because they cannot themselves check them all regularly. We already made them happy (?) with telling them about some disappeared and unuseable benchmarks.

Take a look at our site http://www.geocaching.nl/benchmark/

We have maps (=kaarten) with the status of all the points.

[Prof. Y. Lupardi]

The site is a big success. Since the start just 10 days ago more then 500 benchmarks are visited and nearly 10 were proven to be ''no longer there'. There are about 5000 left to visit.

And for the future? There are also NAP-benchmarks (for height only) to find; about 34.000

[+GEO*Trailblazer 1]

Good work Prof.

It is good to see you out there updating the data for your area.

I am sure like here they appreciate your efforts in this endevor.

 

Keep up the good work.

[+dhenninger]

Darn, and I was just there last week. That would have been interesting. Is the benchmark in Amsterdam (a virtual cache) one of them?

 

Dave

[Prof. Y. Lupardi]

You mean GC509A : Dutch - RD Benchmarks ?

This virtual cache can be used to log finds for bench marks. But the data is unstructured. (on date of visit, not position)

[+dhenninger]

I should have provided a link.

The cache I was talking about was:

GCKPYT - "2C (5) - POINT"

It is listed as the official Amsterdam Ordnance Datum-marker.

 

Dave

[Prof. Y. Lupardi]

Oh yes that one. Very nice tourist attraction that gives some religious or emotional dimension to something very down-to-earth.

Here you can find a picture Café Restaurant Nieuw Amsterdam Peil (not a coffie shop:-)

It is not the real one and only zero marker for our national (and later for our neighbour countries) NAP-level.

This one was specially levelled from the marker that sits under an lid on the Dam (lively centre of town). But that one is one of an whole network of underground markers that are sunk into deep old sandlayers.

And now with modern equipment we found out that the Amsterdam marker is not stable compared to the others in the network...

But it is very difficult to get something stable in an part of the world that is sinking down already for many millions of years (and being filled up with sediments.).

[Prof. Y. Lupardi]

For those interested in Dutch statistics:

We started beginning of November with 5566 marks to be visited.

Now the numbers are:

Visited marks > 1800

Users > 101

Totaal nr. of photographs > 4791

Comments/Ratings > 1623

Image Space > 100.0 MB

Total disk space used > 145.73 MB

PageViews > 35368