AI Assistant
Notifications
Clear all

The dilution of precision (DOP)

10 Posts
8 Users
0 Reactions
401 Views
nate-the-surveyor
(@nate-the-surveyor)
Posts: 10538
Member
Topic starter
Translate
English
Spanish
French
German
Italian
Portuguese
Russian
Chinese
Japanese
Korean
Arabic
Hindi
Dutch
Polish
Turkish
Vietnamese
Thai
Swedish
Danish
Finnish
Norwegian
Czech
Hungarian
Romanian
Greek
Hebrew
Indonesian
Malay
Ukrainian
Bulgarian
Croatian
Slovak
Slovenian
Serbian
Lithuanian
Latvian
Estonian
 

When you have been surveying for a long time, and have developed a serious relationship with reality, and then along comes some upstart, who is FASTER and CHEAPER, and causes less trouble, cause, he can fudge it, then he starts to dilute the precision of the community. Too many surveys, not enough reality.

What's your DOP factor?

I think all surveyors should be given a course in real surveying.

Nate


 
Posted : November 25, 2013 5:53 pm
MightyMoe
(@mightymoe)
Posts: 10534
Member
Translate
English
Spanish
French
German
Italian
Portuguese
Russian
Chinese
Japanese
Korean
Arabic
Hindi
Dutch
Polish
Turkish
Vietnamese
Thai
Swedish
Danish
Finnish
Norwegian
Czech
Hungarian
Romanian
Greek
Hebrew
Indonesian
Malay
Ukrainian
Bulgarian
Croatian
Slovak
Slovenian
Serbian
Lithuanian
Latvian
Estonian
 

All you need is the GIS and a garmin


 
Posted : November 25, 2013 10:15 pm
scotland
(@scotland)
Posts: 903
Member
Translate
English
Spanish
French
German
Italian
Portuguese
Russian
Chinese
Japanese
Korean
Arabic
Hindi
Dutch
Polish
Turkish
Vietnamese
Thai
Swedish
Danish
Finnish
Norwegian
Czech
Hungarian
Romanian
Greek
Hebrew
Indonesian
Malay
Ukrainian
Bulgarian
Croatian
Slovak
Slovenian
Serbian
Lithuanian
Latvian
Estonian
 

It's funny you mention that. There is a misunderstanding by the general public about how good our work is or should be. I agree with your DOP number for surveyors. Seems like the ones that do the crappiest work get the jobs. But when inform the clients about the accuracy my GPS has versus theirs, I blow them away! I would be rich for every time I heard "WOW! That accurate!" Sadly our profession has turned into a similar feeling as auto mechanics. "Who can I find to fix my car for the cheapest?" I ponder now how we can move our profession to a new level.


 
Posted : November 25, 2013 10:23 pm
John Harmon
(@john-harmon)
Posts: 352
Member
Translate
English
Spanish
French
German
Italian
Portuguese
Russian
Chinese
Japanese
Korean
Arabic
Hindi
Dutch
Polish
Turkish
Vietnamese
Thai
Swedish
Danish
Finnish
Norwegian
Czech
Hungarian
Romanian
Greek
Hebrew
Indonesian
Malay
Ukrainian
Bulgarian
Croatian
Slovak
Slovenian
Serbian
Lithuanian
Latvian
Estonian
 

Lost track of how many times I did a preliminary traverse on a tract; set some traverse poinst here and there, some 60d nails for approximate locations to see how things lines up, only to find that another outfit sent some button-pushers out to survey the adjoining tract while I am doing calculations.
Before I could get to back set the actual corners, I see a deed come down the pike using for corners my preliminary points (nails) for corners.
FIND IT, SHOT IT, WRITE IT UP even it not even called for.


 
Posted : November 25, 2013 10:36 pm
half-bubble
(@half-bubble)
Posts: 939
Member
Translate
English
Spanish
French
German
Italian
Portuguese
Russian
Chinese
Japanese
Korean
Arabic
Hindi
Dutch
Polish
Turkish
Vietnamese
Thai
Swedish
Danish
Finnish
Norwegian
Czech
Hungarian
Romanian
Greek
Hebrew
Indonesian
Malay
Ukrainian
Bulgarian
Croatian
Slovak
Slovenian
Serbian
Lithuanian
Latvian
Estonian
 

The dilution of confidence

It's not measurements that we sell, it's the confidence in the overall collection of redundant measurements, together with research and narratives.

Anyone can make a measurement, and usually it's the guys with the precision (but no accuracy) who are setting the pincushions. As in "the new instruments are so precise" or "my GPS is good to half a centimeter." Anyone can buy a gadget that reads to hundredths.

Used to be, to do good work, there had to be some redundancy. Think of those nice plats from the 1950s that were done with a one minute transit and a steel tape, and match both the plat and today's measurements just as good as we could do today. 4 sets, double centering, double chaining, a lot of redundancy went into that and yet sometimes we see people posting about "how could that old timer possibly do a decent survey with a T-16 and a tape?"

Without that redundancy, there is no confidence. Just a modern measurement that is "so good".
When the new tech moved in and people started taking shortcuts, we lost a lot of our defensible confidence. And the public lost their confidence in surveyors.


 
Posted : November 27, 2013 2:29 am

nate-the-surveyor
(@nate-the-surveyor)
Posts: 10538
Member
Topic starter
Translate
English
Spanish
French
German
Italian
Portuguese
Russian
Chinese
Japanese
Korean
Arabic
Hindi
Dutch
Polish
Turkish
Vietnamese
Thai
Swedish
Danish
Finnish
Norwegian
Czech
Hungarian
Romanian
Greek
Hebrew
Indonesian
Malay
Ukrainian
Bulgarian
Croatian
Slovak
Slovenian
Serbian
Lithuanian
Latvian
Estonian
 

It is somewhat satisfying, to do a good job. But, it is sad to see people building their business model on compromise, and lies.

Nate


 
Posted : November 27, 2013 8:48 am
ddsm
 ddsm
(@ddsm)
Posts: 2222
Member
Translate
English
Spanish
French
German
Italian
Portuguese
Russian
Chinese
Japanese
Korean
Arabic
Hindi
Dutch
Polish
Turkish
Vietnamese
Thai
Swedish
Danish
Finnish
Norwegian
Czech
Hungarian
Romanian
Greek
Hebrew
Indonesian
Malay
Ukrainian
Bulgarian
Croatian
Slovak
Slovenian
Serbian
Lithuanian
Latvian
Estonian
 

The dilution of precision (DOP) Nate!

Nate,
I'm surprised you didn't comment on the Brann v. Hulett post below. I figured you would have some input...after retracing so many of Fred's surveys.
DDSM


 
Posted : November 27, 2013 9:00 pm
bill93
(@bill93)
Posts: 9977
Member
Translate
English
Spanish
French
German
Italian
Portuguese
Russian
Chinese
Japanese
Korean
Arabic
Hindi
Dutch
Polish
Turkish
Vietnamese
Thai
Swedish
Danish
Finnish
Norwegian
Czech
Hungarian
Romanian
Greek
Hebrew
Indonesian
Malay
Ukrainian
Bulgarian
Croatian
Slovak
Slovenian
Serbian
Lithuanian
Latvian
Estonian
 

The dilution of confidence

>those nice plats from the 1950s

In my limited experience in this town, some plats are great and the field work may be also, but I have seen several plats that don't close mathematically. Not just by a little bit, but by amounts that exceed what would have been expected in the field work of that day, much less for a plat.


 
Posted : November 28, 2013 10:52 am
nate-the-surveyor
(@nate-the-surveyor)
Posts: 10538
Member
Topic starter
Translate
English
Spanish
French
German
Italian
Portuguese
Russian
Chinese
Japanese
Korean
Arabic
Hindi
Dutch
Polish
Turkish
Vietnamese
Thai
Swedish
Danish
Finnish
Norwegian
Czech
Hungarian
Romanian
Greek
Hebrew
Indonesian
Malay
Ukrainian
Bulgarian
Croatian
Slovak
Slovenian
Serbian
Lithuanian
Latvian
Estonian
 

The dilution of precision (DOP) Nate!

Well, Dan, I am so busy thinking, that I don't have time to solve all the troubles of the world.!!!! (OK, that is not perzactly true, but, I often do retrace the GLO, AND the long standing occupation, and perform a "Community Impact Study". This way, I actually perform a "Professional Service".

I know where the deeds say, and where occupation is, and where GLO puts it.

This is my opinion of professional.

Nate


 
Posted : November 28, 2013 11:36 am
dave-karoly
(@dave-karoly)
Posts: 11990
Member
Translate
English
Spanish
French
German
Italian
Portuguese
Russian
Chinese
Japanese
Korean
Arabic
Hindi
Dutch
Polish
Turkish
Vietnamese
Thai
Swedish
Danish
Finnish
Norwegian
Czech
Hungarian
Romanian
Greek
Hebrew
Indonesian
Malay
Ukrainian
Bulgarian
Croatian
Slovak
Slovenian
Serbian
Lithuanian
Latvian
Estonian
 

Our profession is essentially unregulated.

Sure a surveyor here and there gets slapped by the board but usually for the wrong things.

If the surveyor does a wonderful job of digging up monuments and measuring every thing to the tiniest fraction of a millimeter then sets corners 2' from the established boundaries he gets the blessing of the board. Too many surveyors just blithely ignore decades of history in favor of the magic number spit out by the machine.


 
Posted : November 28, 2013 12:32 pm