Digital Terrain Mapping of Greens

[rchesnut]

As many of you know, Pasatiempo just finished a pretty substantial restoration project, and the club is looking to ensure that the work is accurately preserved for the future.  It was a major effort to do this restoration (relying on a lot of old photos), and it looks like there are some intelligent and pretty hi-tech ways to make it easier to track changes in the course and ensure that time (mowing patterns, bunker sand on greens, erosion, etc) doesn't undo the work.

As I came off the course today, our super called me over and introduced me to a guy from a company called greenscan3d, which claims to do highly precise 3D surveying and digital mapping of greens.  He showed me a computer screen with our 18th green, it looked very cool.  Does anyone out there have any experience with this product, or other technologies that provide a similar service, that we should be looking at?

Rob

[Doug Siebert]

I remember asking about this here a few years ago, thinking of its application more in terms of linking it with GPS guided equipment to allow very accurate reproductions of existing greens.  Probably still a few years off, but moreso than being able to insure a course's own greens stay true to themselves over the decades, I think it would be used to allow building copies of great greens at new sites.

Obviously it would be subject to the types of grasses and soils, and expected greens speeds, so you can't try to build TOC's 12th in on clay soil with A4 bent.  I'm sure it would be abused but hopefully it would also be used in positive ways as well.

If nothing else, it would allow the greens in the Tiger Woods video golf games to be true to the originals!

[Tom_Doak]

Rob:

There are two or three such companies.  I'll send you a couple of names if you want them.

[Adrian_Stiff]

I do my own mapping and I reckon I can do 3 greens in a day.
Using a piece of string say 35 metres in length with knots every 2 metres I draw a line across the green and measure the points every 2 metres with the camera to an accuracy of about 10mm then simple place the number on the corresponding grid of scaled graph paper so each quadrant represent a 2 metre point, at the end of each line move each peg back 2 metres, it normally takes around 10-15 moves.
Take the graph paper and simply plot the new contours by interpolating the midpoints... I do it to 25mm ie 1" contour levels, if you can see unusual aspects within a green take further measurements. I cant see the need to do it more accurately and I doubt that its possible to construct as accurately either but it did allow us to reconstruct one green as it was before for a course. I think all greenkeepers/ supers should map their greens, quite a usefull thing to have for the files.

[Mike Nuzzo]

Rob,
All the companies will use a centimeter grade GPS system - it requires a rover and base station set up.
Data is data as long as they walk slow and are careful.

You can have a wheel on the bottom of the pole that holds the rover or just be careful with keeping the point just above the grass - I've used both methods.

If they can present the data in a good format I'd use them.
Can you post a picture?

Adrian -
I'm impressed with your abilities and methods.
Why don't you use GPS?
Mapping greens with a GPS system takes about a day for all 18 including green complexes and bunkers.
It is only $400 to rent a centimeter system per day here in TX.

Cheers

[Davis Wildman]

Rob,

There are a number of methods, either stand-alone or integrated tech that will provide archive level  or record drawings of greens' contour and surfaces.  GPS is one; specifically survey grade or RTK GPS (centimeter as Mike N says)  is one of the more accurate and cost effective methods to go about it...but it requires a fair amount of back office post processing of the data to achieve 0.1' vertical accuracies at 3" contours.
 
We've produced many datasets for various architectural and design firms and clubs nationally who either wanted to restore as faithfully as possible the greens surfaces to their former contours before renovation or for producing 3D or design grade digital terrain models of their greens for historical preservation or future renovations.

GreenScan3D or more precisely 3D Laser Scanning is a very accurate method to do this.  As Tom Doak noted, there are other companies doing this kind of work using various technology and methods.

Producing precise and accurate greens models for architectural purposes requires our company more than one day to do all 18, especially if we map while play is on-going...but that's a simple matter to address.

Submeter GPS, with x/y (horizontal) errors in the +/-3' range (that's radius, not diameter) coupled with poor vertical elevation values just won't do the job; even if a laser level is employed.  There is simply too much variance in the x/y and z positions...that's horizontal and vertical values to capture all the subtle undulations...if that is the goal. 

The newer 1 ft accuracy gps receivers won't do it either because they can't produce consistent and accurate vertical values either.

Feel free to contact me off forum if you'd like to discuss more at length. 

Best,

davis@terravea.com



 

[Adrian_Stiff]

Rob,
All the companies will use a centimeter grade GPS system - it requires a rover and base station set up.
Data is data as long as they walk slow and are careful.

You can have a wheel on the bottom of the pole that holds the rover or just be careful with keeping the point just above the grass - I've used both methods.

If they can present the data in a good format I'd use them.
Can you post a picture?

Adrian -
I'm impressed with your abilities and methods.
Why don't you use GPS?
Mapping greens with a GPS system takes about a day for all 18 including green complexes and bunkers.
It is only $400 to rent a centimeter system per day here in TX.

Cheers

I guess I have not moved with the times. How easy is it to convert the data into a readable drawing?

[Davis Wildman]

Data conversion is very straight forward if you are familiar with the process.  To say it another way, the terrain modeling tools are well developed and integrated these days. 

Learning how to go from the collected field data to finished terrain model will require a concerted effort and a fairly good understanding of the software(s) in order to be proficient.

I'd not let that be a deterrent to learning how if your work requires greater accuracy and efficiency in order to produce data you need to do your job...or if it will make your work more attractive (i.e., easy to integrate into their work-flow) to your associates who work in the 'digital' world.



 

[Steve Lang]

  

Surfer is an old standby PC program for creating 3d pictures, with capability of using various interpolation methods between the measured points..  just put xyz data into a spreadsheet, import, convert to grid file and voila, you can make 3d pics in a minute.. then rotate and view from any angle..   and overlay as you desire.  Used extensively in groundwater modeling and air disperison modeling studies..

[Reef Wilson]

A friend and I were talking today about the "Aim Point" (or should I say the "Mutual of Omaha Aim Point"?) technology the golf channel was using this last week for the match play. I have assumed that they must have this detailed info about the green contours that allows them to calculate and accurately show the line the putt needs to take to go in the hole.

Very cool stuff but we were speculating that they could not use this when the tour plays on greens where grain is a factor, like when the tour goes to Florida. Also, I assume the system would have to know the current stimp readings? Any of you with the expertise have any further thoughts on that?