Geocaching Australia

Quoted from earlier in the thread (which I don't think anyone should have to read )

caughtatwork wrote:Let me throw some words around (that I googled and therefore don't understand).

A benchmark is a point of reference for a measurement. In surveying a benchmark is set by a surveyor to mark a point of known vertical elevation. These marks may be chiseled into a wall or they may be small brass or aluminium disks, concrete posts, iron pins or bolts that are permanently attached to a stable foundation.

Triangulation points are marks used to establish horizontal position. These points may be marked by disks similar to benchmark disks. Often prominent features on buildings such as the tip of a church spire or chimney stack are also used for triangulation.

The difference appears to be benchmarks are used for vertical elevation and trigpoints are for horizontal position. As the cache type trigpoint is for trigpoints I don't think we're looking to have benchmarks included in that cache type.

Got that picture yet?

caughtatwork wrote:Quoted from earlier in the thread (which I don't think anyone should have to read )

caughtatwork wrote:Let me throw some words around (that I googled and therefore don't understand).

A benchmark is a point of reference for a measurement. In surveying a benchmark is set by a surveyor to mark a point of known vertical elevation. These marks may be chiseled into a wall or they may be small brass or aluminium disks, concrete posts, iron pins or bolts that are permanently attached to a stable foundation.

Triangulation points are marks used to establish horizontal position. These points may be marked by disks similar to benchmark disks. Often prominent features on buildings such as the tip of a church spire or chimney stack are also used for triangulation.

The difference appears to be benchmarks are used for vertical elevation and trigpoints are for horizontal position. As the cache type trigpoint is for trigpoints I don't think we're looking to have benchmarks included in that cache type.

Got that picture yet?

Nope my partner in crime is obviously hard at work and not reading his personal emails or watching the forum (i should be working but ive done enough for today)

But it is clearer now what a Benchmark vr's a TrigPoint is funnny thing is that i have read the quote but it just didnt register (i am blaming the 41 caches & 1140km that we did caching on the weekend)

Unfortunately, I beg to differ on a benchmark, or perhaps things have changed since the old days. A set height? I have a cache, which sits immediately below a very old Benchmark bazed into the trunk of a tree. BM underlined is the blaze. It was identified by a certain spatial ranger called Dandent.

I could take a pic if someone wanted.

Cheers
Bundy

Well the photos are up on the listing now caughtatwork http://geocaching.com.au/cache/tp5330

Unfortunately after looking at the Photos and reading through this thread I have realised that we didnt remove the metal cover to access/capture the Metal plate

instead we took a pciture of the Concrete Box and the lid

Looks like I might need to take a trip (again) to Alabany to confirm whether or not it is an acutal Trig Point

Just looking at the picture with the yellow survey marker sign, this appears to be a survey marker, which I think is not the same thing as trigonometrical station.

The question is whether it should stay as a TrigPoint or whether it would be best to be archived and you to log your find against the WA Survey Mark locationless cache.

Only YOU can decide that.

If you feel that this is a survey marker rather than a trigonometrical station and that having people visit this location in the hopes of finding a TP would leave the finder unsatisfied, archive the listing and log your find against the WA Survey Mark locationless cache.

If on the other hand you feel that this is a genuine trigonometrical station and that people won't be disappointed when they visit the location, then leave it be.

Your decision, your choice.

I shall discuss with the_robots about what we shall do.

caughtatwork wrote:Just looking at the picture with the yellow survey marker sign, this appears to be a survey marker, which I think is not the same thing as trigonometrical station.

The question is whether it should stay as a TrigPoint or whether it would be best to be archived and you to log your find against the WA Survey Mark locationless cache.

Only YOU can decide that.

If you feel that this is a survey marker rather than a trigonometrical station and that having people visit this location in the hopes of finding a TP would leave the finder unsatisfied, archive the listing and log your find against the WA Survey Mark locationless cache.

If on the other hand you feel that this is a genuine trigonometrical station and that people won't be disappointed when they visit the location, then leave it be.

Your decision, your choice.

Well the Trig Point has been archived, better to archive it than have complaints from other cachers

Well it has been a very good learning experience and I have learnt:
1. The difference between trig Points, Benchmarks & Survey marks
2. It pays to actually lift the cover that is "covering" the marker
3. You should always read the forum from front to back carefully

And that the people in this forum are extremely helpful...thanks to everyone for their help

Greetings,
My input may make things clear or cloudy.
A benchmark is a general term for a survey mark of known vertical value.
The vertical value:-
can be a published Continental/National Geoid value such as the Australian Height Datum (AHD) [Note, your GPS unit will give you an world spheroidal value)
or
it could be a local vertical datum, i.e. Williamstown LWM
or
it could be an abitrary value made up by the surveyor for his convenience.
All survey marks could potentially be a benchmark.

Survey Marks are generally placed to serve a particular purpose, i.e. Geodetic, Cadastral, Construction, Monitoring, etc
Added to this all survey marks have a published rank (or Order as it is called in the industry) of precision.
Trig Points have the highest order of precision, generally horizontal, however I know of Trig points with no published values (2D or 3D)
I have come across a Trig beacon with a standard plaque in the ground.
Non trig plaques can also have an equal order as a trig point.
Geodetic Bench Marks have the highest order of vertical AHD value.
Survey marks can come in cast iron, concrete boxes, raised or below ground, pre-cast or in-situ, deep seated or shallow; there are a multitude of survey marks types.
In Victoria and I'd expect the same in other states, the types of registered survey marks are governed by Acts & Regulations such as the Survey Co-ordination Regulations 2004, SCHEDULE 18 PERMANENT SURVEY MARK TYPES, however it is known that this is not always followed and survey marks made up of a aluminium rivet or nail in concrete or kerb have been registered.

As you can appreciate the Survey Mark world has not evolved in an orderly fashion and it is understandable that confusion can arise.

It is interesting to note that Trig Points will become consigned to history with the advent of GPS/GNSS as the need to put a point on a hill is redundent. The stability of the mark is now the primary concern when registering a survey mark using differential GPS tecniques, but alas, that is another story.

PS
A registered survey mark is one that is published by the states respective Office of Survey General.
Not all survey marks found on the ground are registered.

I have seen a number of Trig point listing which have an archive log on them which are still active.

As a couple of examples Hemmant Area TP3035 and Morningside Area TP3288. I don't know if there are others.

I thought the Archived log would have archived them immediately or is there something else which has to be done to clear them off the Active list?

crew 153 wrote:I have seen a number of Trig point listing which have an archive log on them which are still active.

As a couple of examples Hemmant Area TP3035 and Morningside Area TP3288. I don't know if there are others.

I thought the Archived log would have archived them immediately or is there something else which has to be done to clear them off the Active list?

I just re-did the archived log on these and now they are gone.
Looks like something didn't trigger off the archiving on the system when it was archived by a non-admin or owner. I'll look when I get home!

Thanks for pointing that out.

I've checked the code and run a few tests on my dev box and there is nothing that should stop the cache being archived when an archived log is logged, regardless of who has logged the archived log.

However if someone logged a "Needs Archiving" log against the cache, then changes the log type to an "Archived" log, the system will NOT archive the listing. The reason for this is that we can never know if the change was performed on the LAST actionable log. i.e. They may have been done out of order.

I will add a message to the page so that if someone edits TO an actionable log type, they will be prompted to log the correct log type as a new log. Then we can be certain that the action was intended.

I came across a trig marker the other day and have added a new cache entry for it (TP5354) - but the cache editing page wouldn't allow me to add a gallery photo for it (maybe because I set the owner as GCA, or maybe not). Anyway, I did a dummy log so I could have the photo displayed on the cache page and now I'd like it removed (but not the photo, obviously - I tried this myself and it deleted the photo too).

Could the faeries assist me here?

Let me look. I didn't think about images for the trigpoints.

I've published a fix.
Can you please edit the cache, at the bottom click on add an image.
Try to upload the image (it should now work).
The image will be owned by YOU, not GCA.
You should now be able to add it into the cache listing and delete your log.

caughtatwork wrote:Let me look. I didn't think about images for the trigpoints.

I've published a fix.
Can you please edit the cache, at the bottom click on add an image.
Try to upload the image (it should now work).
The image will be owned by YOU, not GCA.
You should now be able to add it into the cache listing and delete your log.

OK, it's all good now - does that count as a GCA cache for the anniversary celebrations (just kidding)

Did you hide it on the 18-May-2010? Then no smiley for you