Most of the replies here refute what Ted is saying based on the fact that no orthophotos set in a GIS can match a modern boundary survey, which of course is true. However, I will point out that many people may be willing to accept a lesser quality parcel representation for a much lower price. It sounds like blasphemy to us, but it won't to "them", and they won't take our feelings into consideration. They are out to build a better mousetrap, and to cut out all of the middlemen that they can.
I am currently working at a company that maps transmission lines using helicopter-based LiDAR. Less than a decade ago, power companies paid survey field crews to locate power lines and measure the sag, and vegetation encroachments, and other things. Now, the helicopter-based mapping approach is strongly predominant because the cost is dramatically lower, and much more information is obtained. An average day of flight will cover over 100 miles of powerline. Of course the error tolerance is much less precise than conventional surveying methods; maximum 5cm allowable, but that is deemed acceptable for its purpose.
Most GIS cadastral layers I see are pretty messy. Property lines running down the middle of driveways, occationally running through buildings. But they are getting better and will continue to do so. I don't know of anywhere that uses GIS parcel representations to legally describe land as a basis for conveyance. But I surmise that it may come to that.
Stephen
I may not be surprised should such a day come, BUT..... I have heard of numerous lawsuits over 0.1' of land or encroachment in some wealthier areas. When properties sell for a multimillion price tag, I might suspect the owner would not want someone encroaching at all on their land. Will GIS get that good? Not for me to say.
I agree with Stephen.
And pigs will fly before the sole legal description of a parcel of land ceases to be found in the deed.
> I agree with Stephen.
>
> And pigs will fly before the sole legal description of a parcel of land ceases to be found in the deed.
Not sure what you mean, Carl. It may be possible to describe land as represented on a GIS cadastral layer. That is how the legal description in a deed might read.
Stephen
Where to begin?
2012 is 25 years (plus or minus) into the GIS system at the local county. When they first broached the idea they offered it out for proposals to surveying companies to input parcel info into the computer system. The winning bid was for 6 weeks of work. Needless to say it wasn’t very accurate.
This is a typical result that I selected at random. I actually thought it might be “off” north and south in this area, the east-west "error" was unexpected. But, GIS never stops surprising me.
When will we get accurate GIS?
Possibly never.
How will it happen?
When local counties/cities are forced to do it.
The O.P. is 19 days late.
> > Once rectified, these Parcel GIS Maps can produce state plane coordinates (and/or latitudes and longitudes) sufficient to produce boundary maps for most, if not all, boundary requirements.
> >
And all it will take to rectify, is a boundary survey!
As this high grade GPS becomes more available to the public it is inevitable that within a short period of time this new technology will cause the traditional boundary surveys by licensed (registered) land surveyors to be unnecessary.
Posted by the OP as indisputable, it requires some thought.
Obviously a cadastral layer populated with current deed data will contain all of the challenges, errors, gaps, laps, etc. which are contained in the deeds and keep us boundary surveyors in business. That is the situation which many of us have today. So the only way to make this gis absolutely as reliable as a survey is to survey absolutely every parcel to the current standards of the state, monumented, and have them inserted into the cadastral parcel by registered surveyors, not cad techs...
The cost will be enormous and there are probably not enough surveyors or money to make this happen in my lifetime.
A couple of hundred years of case law will also have to be thrown out. The legal status of a coordinate as a deed call is about the same as a direction and a distance, of which it is a product. And our coordinate systems seem to change slightly every few years. How will members of the public with their high precision gps units deal with that? I can see a member of the public pulling out a mark and moving it to where the gps indicates it should be. We will have a whole army of "fixers" out there.
It's just an unworkable can of worms. Even if it were somehow affordable it would be opposed by the state bar association, the realtors board, and the land surveyors (not nearly as important as the first two).
Ted-
I trust you will gain some cadastral field experience under the tutelage of an experienced cadastral surveyor to supplement your PhD. studies sufficient to recognise that your theoretic logic path is a mere polemic.
Your logic is as would a dentist-to-be believing a tooth brush will end all caries.
63+ years of cadastral surveyingly yours,
Derek G. Graham
> Where to begin?
>
> 2012 is 25 years (plus or minus) into the GIS system at the local county. When they first broached the idea they offered it out for proposals to surveying companies to input parcel info into the computer system. The winning bid was for 6 weeks of work. Needless to say it wasn’t very accurate.
>
> This is a typical result that I selected at random. I actually thought it might be “off” north and south in this area, the east-west "error" was unexpected. But, GIS never stops surprising me.
>
> When will we get accurate GIS?
> Possibly never.
>
> How will it happen?
> When local counties/cities are forced to do it.
Here's one I didn't pick at random. It's my house and I KNOW the GIS (yellow) lines are not correct. The red lines that I've drawn are much closer to correct... and as our website clearly states, "for informational purposes only".
What about corners that fall in tree cover, or large trees AS corners. I think us surveyor will be fine for some time... assuming the economy recovers.
Carl
Mr. Madson,
Are your questions rhetorical? If not why do you avoid participating in the general discussion you initiated?
Simians are naturally curious.
Good Grief!!! Are you for real? Oh, I get it know, Ted forgot to use the sarcasm font!
Whew!!! Scared me for a minute.
I would have to say that your statement "Once rectified, these Parcel GIS Maps can produce state plane coordinates (and/or latitudes and longitudes) sufficient to produce boundary maps for most, if not all, boundary requirements" fails in many ways.
A boundary survey would need to be affixed to the GIS data for every parcel in the United States for that to happen. There is an insufficient number of actual surveys made to encompass every parcel. Many of the ones that exist are not in agreement of one another to the necessary degree of accuracy of a proper survey.
The GIS data that has been merged with actual surveys only cover some and not all metroplex area, such as Houston and a few other cities that have recorded and assembled their information together.
Many areas are still not in the digital world and will not likely be there in my lifetime.
The need for boundary surveying will always be needed somewhere. The surveyor still has to preform their duties on the ground and not from an armchair.
GIS is one of many tools and not a complete service.
Posted a [msg=135352]LONG reply[/msg] to Ted's duplicate message under Land Surveying. Linking it here since this thread appears to be getting more activity.
I think there is more truth than error in the premise of the questions. All I will add is surveyors can add quality to GIS by placing their surveys on the same coordinate system the the county is on and providing it to them in a format they can plug in. Why continue to exhibit how bad things are when we have the expertise to improve it one parcel at a time? The two groups are either going to coexist or one will go away. It won't be GIS. Also, the more surveyors cause line disputes the sooner the time will come when GIS will be the chosen option by the public. How many property owners would pay for a survey and to assist them to get there lines drawn correctly onto the county GIS so the line doesn't run through their garage? If you can't beat em join em. Billable hours my friend.
I have had several offers from Indian companies willing to perform all the GIS work I can send them for 8-10 U.S. dollars an hour. I think surveyors need to embrace new technology and I appreciated the advances made by higher degree study in the field and that some aspects can not be outsourced overseas. Nevertheless, I am of the opinion that surveyors would be better served by pursuing greater education and training in areas more closely related to field engineering. Things like wetland identification, storm water, sediment and erosion control. These regulatory areas need boots on the ground due to the micro nature of the mapping and mitigation design, and its reliance on close inspection of physical properties of the earth that mere visual inspection by lidar can not accomplish. Property lines no longer define the useable area of lands. Many projects can be performed without ever knowing exactly where the property lines are, but can not be performed without defining the exact limits of regulatory boundaries that require knowledge of soil type, vegetation, hydrology.
In many areas the existing county systems coupled with submeter handheld GPS are probably sufficient for most property line questions. But in order to do anything with the property someone is going to have to identify and map the regulatory boundaries. It's sad that surveyors are not the ones doing this.
> I have had several offers from Indian companies willing to perform all the GIS work I can send them for 8-10 U.S. dollars an hour. I think surveyors need to embrace new technology and I appreciated the advances made by higher degree study in the field and that some aspects can not be outsourced overseas. Nevertheless, I am of the opinion that surveyors would be better served by pursuing greater education and training in areas more closely related to field engineering. Things like wetland identification, storm water, sediment and erosion control. These regulatory areas need boots on the ground due to the micro nature of the mapping and mitigation design, and its reliance on close inspection of physical properties of the earth that mere visual inspection by lidar can not accomplish. Property lines no longer define the useable area of lands. Many projects can be performed without ever knowing exactly where the property lines are, but can not be performed without defining the exact limits of regulatory boundaries that require knowledge of soil type, vegetation, hydrology.
>
> In many areas the existing county systems coupled with submeter handheld GPS are probably sufficient for most property line questions. But in order to do anything with the property someone is going to have to identify and map the regulatory boundaries. It's sad that surveyors are not the ones doing this.
You are joking too right? The "exact" limits of "regulatory" areas are what licensed land surveyors should focus on, as property boundaries can be handled at the "submeter" level with and by GIS. Good grief 🙁
Interesting topic and one that comes up more and more as GIS becomes more prevalent.
If you think GIS parcel mapping will ever become accurate enough as a whole to make surveying obsolete you are dillusional. A boundary survey is not about coordinates, it's not about Lat-Long....those are produced as a result of an accurate land survey. Therefore the only way to make your statement true is to conduct a proper land survey of every parcel. Even then....monuments will typically (not getting into this now) hold over a coordinate or lat-long position from a GIS map.
I have personally mapped 2 complete counties in one of our lovely northwest states. All mapping was completed based on record deeds, plats, real information..... A certain amount of section corners were tied, as much as the budget could allow, and used as the basis within each section. I consider this a high accuracy GIS, much higher than most but it is a FAR CRY from being able to be used as a boundary survey.
GIS stands for Get It Surveyed....at least that's a common acronym around here and a good one to live by. GIS is a tool, a great tool....it is not a boundary survey.
I can only conclude that Mr. Madson is not a boundary surveyor, for he seems to have missed one of the most fundamental principles of surveying. As such, this post does not warrant further comment.
> I have had several offers from Indian companies willing to perform all the GIS work I can send them for 8-10 U.S. dollars an hour. I think surveyors need to embrace new technology and I appreciated the advances made by higher degree study in the field and that some aspects can not be outsourced overseas. Nevertheless, I am of the opinion that surveyors would be better served by pursuing greater education and training in areas more closely related to field engineering. Things like wetland identification, storm water, sediment and erosion control. These regulatory areas need boots on the ground due to the micro nature of the mapping and mitigation design, and its reliance on close inspection of physical properties of the earth that mere visual inspection by lidar can not accomplish. Property lines no longer define the useable area of lands. Many projects can be performed without ever knowing exactly where the property lines are, but can not be performed without defining the exact limits of regulatory boundaries that require knowledge of soil type, vegetation, hydrology.
>
> In many areas the existing county systems coupled with submeter handheld GPS are probably sufficient for most property line questions. But in order to do anything with the property someone is going to have to identify and map the regulatory boundaries. It's sad that surveyors are not the ones doing this.
:good: I think you are on to something Duane.
Ralph
The O.P. is 19 days late.
Madson Postulated the same ignorant opinion over on LinkedIn in one of the discussion groups. He is getting ripped there also.
He is making false assumptions. Ted is good at that.B-)