This morning I was provided a set of coordinates in L,L (no h) and told to convert them to NAD27 SPC.?ÿ I asked what datum the coordinates were in and was met with a slack jawed, blank stare.?ÿ Now this is to be expected with some of our salesmen as they don't necessarily have a surveying background.?ÿ I asked them to call the customer to confirm.?ÿ The "surveyor" could not or did not understand either.?ÿ He deferred to his tech working in another state and out of cell coverage.?ÿ?ÿ
With some surveyors, I understand.?ÿ They work with total stations and assume coordinates on all jobs, never tying anything to the NSRS.?ÿ This is completely fine for the large scale boundaries they work in.?ÿ Where this customer is going though, is soon to be a very exclusive planned community where homes prices start around $500k and go well north of a million.?ÿ Most of the time I will do my damndest to help out a customer, but I noped the hell out of this one...?ÿ If you can't give me the most basic info on how your coordinates were derived, you're on your own!
Sanity, logic and order are mere words sometimes.?ÿ Welcome the mad house we call "our industry".?ÿ 😉
It doan matter. Yer de prefesshunal I thought you could figger it out!!
And why does anybody want NAD27 these days?
Edit: Oh, they probably are planning with the aid of USGS topo maps.
Heck send a link to Corspcon and be done with it.?ÿ
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NCAT. Corps on has not been supported for years now.
@bill93?ÿ It may or may not be oil & gas related, I'm not sure.?ÿ Most O&G projects are done in NAD27 still, at least in Texas.?ÿ It would cost too much for most operators to convert their records to NAD83.
I'm not sure if you can still find CORPSCON 6 to download, but it works fine for many purposes if you have it. There is one know bug.
To get the correct combined scale factor, the input may be selected to either datum, with the appropriate height value, but the output MUST be selected to be NAVD88 for the combined factor to be correct.
It always uses the output elevation number to compute the combined factor, always treating it as NAVD88 regardless of what was selected.
It's still downloadable, I only know that cause I was looking for it on my hard drive and it was missing so I redownloaded version 6. That was a few months ago.?ÿ
I often do "favors" for good return clients, most of the time they involve scheduling bumps to do their work quicker.?ÿ There is only one way I would touch this job and it wouldn't be a free "favor".
If a client wanted me to do this, I would advise them that I can not, and will not, take on the liability of converting points to any datum, regardless of the intended use, until I field verify hard points with the coordinates that were provided. How would I know how these points were collected??ÿ With GPS, there are too many things that can go wrong in the hands inexperienced operators and processors.?ÿ If I had no control over the original work or wouldn't get paid to verify it while answering all the questions with my own work, absolute no go!
I completely get your frustration, and a "surveyor" who can't explain his data in inexcusable, but don't forget that a well run survey with a good total station is still more precise than most RTK surveys.?ÿ
My first question would have been, "Who thinks they need anything different from what you have been provided and what authority do they have to make this demand??ÿ My job had certain criteria.?ÿ You are now wanting different criteria.?ÿ We can get you what you think you need but it will cost you."
This morning I was provided a set of coordinates in L,L (no h) and told to convert them to NAD27 SPC.?ÿ
You had me right there. A surveyor who has to farm out a simple datum conversion isn't going to know jack all about datums this or realizations that.?ÿ You should expect that you are going to earn 9/10 of your fee just running down the metadata. Metadata being another word that isn't in that surveyors vocabulary.?ÿ?ÿ
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This is standard procedure.?ÿ It's like when a certain computer using a specific software hiccups.?ÿ You yell for Seigfried the computer savant to come to your desk and fix it.?ÿ Not everyone in upper management is an expert on everything that it would be nice if they were.?ÿ Never happens.?ÿ That's why you employ people who enjoy being wizards at certain things, but, not necessarily everything.