Tips on Purchasing a Laser Scanner

Written by Michale Olsen
Saturday, 26 May 2012

The selection of a laser scanner can be a difficult decision.  Let’s face it, they all are cool and it would be nice to have one of each!  But ultimately, it is a significant investment and you want to make sure that you get the optimal value out of your purchase.  Laser scanners may have specific purposes, environments, or applications for which they are best suited.  Caution must be used when comparing scanner specifications because there are no consistent standards for testing and reporting, although the ASTM E57 committee is working to address this issue.  For example, the accuracies of scanners vary non-linearly with distance and some manufacturers publish accuracies at 50 m and others at 100 m.  Overall accuracies are influenced by the surface being scanned, geometric configuration of the scanner and target, environmental conditions, laser properties, and many other factors.  Point of Beginning offers a very helpful list of specifications (usually updated yearly) for a variety of scanners and should be consulted by anyone looking to purchase a scanner.

As I have discussed in previous articles, scan geo-referencing can also induce error.  For example, the accuracy of a survey grade GPS unit is typically 1.0 cm in the horizontal and 2.0 cm in the vertical.  Thus, data acquired from a scanner with a millimeter level accuracy will no longer be of millimeter accuracy if GPS is used for the scan geo-referencing.

Some criteria that should be weighted in the selection of a scanner include (although not limited to):

1. Type of laser (wavelength) – How well does the laser reflect off the type of surfaces to be scanned?  Are you scanning metal objects, topography, wet surfaces, dark surfaces?

2. Spot size (pulse width, beam divergence) – What will be the size of the laser spot on the target?  Do features smaller than this need to be modeled?

3. Speed – The most common question/metric is: How many points does it collect per second?  Most scanners are fast so this is not the most crucial ifnormation.  A more important question is: How much setup time (e.g. mount the instrument, boot up, select scan window, acquire imagery\targets, and scan) is involved?  The latter can dominate a lot of the actual field time required.  Another question is how much processing is required and what workflow optimizations are presented by the scan manufacturer.

4. Field of View – How wide is the scan view? (Many scanners can scan 360 degrees horizontal, but have a limited vertical window).

5. Accuracy – What level of instrument measurement error is acceptable to fit into your overall error budget?  This will depend on the intended applications.

6. Resolution – What point density is achievable/required?

7. Range – How much coverage is needed in a single scan?

8. Geo-referencing – Does the scanner have a calibrated GPS mount for geo-referencing? Or are external targets required?

9. Level compensators\Inclination sensors – Can the scanner correct for out of level setups, improving data quality?

10. Mobility, durability – Is the scanner designed for field operation?  Or is it meant to be an indoor scanner?

11. Photography – Do you need photographic information? Does the scanner use an internal or external camera?  What steps need to be taken to map the photograph to the point cloud if it is external?  Is the photograph taken simultaneously or as an additional data collection procedure?  How long does this take?

12. Software – What software package is used for aligning and meshing the scans? What features are available?  How does this package integrate with the other packages you are currently using?

13. Effects on humans – Is it eye safe? Will it set off security alarms (e.g., in cultural heritage applications, you may be scanning in a museum with an alarm system (I have had that happen before!))?

14. Maintenance – What are the costs associated with maintaining the scanner?  Many manufacturers offer maintenance packages.

15. Upgrades – Scanner technology evolves quickly.  Would you be able to upgrade your scanner (or obtain a trade-in credit) when it is time to upgrade?

Obviously you would also want to do a cost/benefit analysis when comparing different systems.  Ultimately, invite the manufacturers out and have them demo the scanner in the environment you will be using it in most frequently.  Also, ask them to let you demo the software so you can get a feel for the workflow and how that will integrate into your current operations.

If your agency is looking to purchase multiple scanners, a few questions arise.  Do you want to go with various types of scanners so that you have a versatile amount of equipment for any job?  Or is it better to standardize your equipment so that all personnel are using the same scanner, reducing training costs?

Good luck in your new scanner purchase!

originally published at LiDAR News http://www.lidarnews.com/content/view/9015/

Changes…

Technology moves so fast these days it is almost impossible to keep up with it all, but it is important that we do all we can to at least be aware of the changes.  You don’t necessarily need to rush out and buy the newest “thing” today, but you should know it is out there and how it will or can impact you, especially as a business owner.

In the CDS newsletter “Tools of the Trade” this month I did a technical segment on Building Information Modeling (B.I.M.) and the role of the Surveyor in B.I.M..  A year or even two years ago it was important to know what B.I.M. was about and that it was coming, today it is important to be looking at ways to take advantage of B.I.M. and position your company to be a B.I.M. Expert.

The role of the Surveyor seems to be changing in many ways today.  While some may look at the changes as negative, others see opportunities.  In the Construction world we have seen more and more companies move to 3D machine control and fewer and fewer stakes going in the ground.  Many would look at that and say the machines are taking the job of the Surveyor, but we should be looking at this as an opportunity.  As a Surveyor we should be building models, tying in control, providing checks, and performing other services that Surveyors are already able to do, but maybe not used to doing.  There is an article written by Houston Neal titled “Automation of Surveying Creates Disruption and Opportunities” that I think covers this topic very well.

Just getting back from the SPAR 2011 Conference I too am well aware of the changes that have happened in the last year as well as the changes coming.  Who would have thought that the scanner I use on my game console could be used to gather data for making working 3D models?!

B.I.M., HDS, Machine control, GPS, data collection, Field to Finish, or any other topic that affects, influences, or otherwise impacts your business is probably something we know about or deal with on a regular basis.  I want to be your partner in these changes and do everything I can to keep you as informed as possible and make sure we find ways to leverage your abilities and capabilities to keep you moving forward as things continue to change.

Trimble Introduces New Field Layout Software Suite

Trimble Introduces New Field Layout Software Suite that includes Trimble
Field Link for MEP and Structures Trades

SUNNYVALE, Calif., Jan. 13, 2011 — Trimble (NASDAQ:TRMB) introduced today its new field layout software suite that includes Trimble® Field Link for MEP and Trimble Field Link for Structures. The latest additions to Trimble?s field layout portfolio incorporate a version for MEP trades and a version for steel and concrete contractors distinguished by trade-specific feature sets. Using the ruggedized 7 inch touch-screen Trimble Tablet Rugged PC, Trimble Field Link can dramatically improve the productivity of field personnel performing lay out by providing more information readily at their fingertips.

Featuring task-based workflows, customizable views and a new user-interface designed to optimize the information presented, Trimble Field Link extends field layout capabilities. In addition to the advancements made in performing layout specific tasks, Trimble Field link adds reporting routines to detail layout productivity as well as the ability to document existing site conditions for RFI’s. Contractors working with Building Information Modeling (BIM) can now view 3D DWG and DXF design models in the field with Trimble Field Link, allowing field crews to make more informed decisions when problems arise.

Trimble Field Link was designed for the Trimble Tablet to take advantage of a larger touch screen, additional processing power, increased storage, Internet connectivity options and a full version of Windows 7. As a fully-functioning PC, the Trimble Tablet provides contractors the flexibility to run additional business applications.

“With the Trimble Tablet, we saw an opportunity to take our field layout software to the next level,” said Pat Bohle, general manager of Trimble’s Building Construction Division. “By enabling functionality such as job-level productivity reporting and the ability to review construction data in a 3D environment while in the field, the new solution empowers field crews with more information for timely decision making and increased efficiency.”

While the base features of Trimble Field Link are the same for MEP, concrete, steel trades and general contractors, Trimble has developed modules with feature-sets designed specifically for each contractor type. Trimble Field Link for MEP includes a Visual Layout module for automated layout and identification of indoor points associated with MEP systems. For concrete, steel trades and general contractors, Trimble Field Link for Structures contains modules that allow the creation of points from CAD files and the measurement of line work.

Trimble Field Link is expected to be available in the first quarter of 2011 through Trimble’s Authorized Distributors of layout solutions for MEP and Structures contractors.

URGENT: A bug in Carlson Software regarding daylight savings

There is  a bug which can lead to the settings loss (menu and toolbar customization) on Carlson 2010 or 2011 and AutoCAD 2010 or 2011.

If you are running one of these combinations and have not yet opened your Carlson 2010/2011 since the daylight saving time change, please follow these instructions:

1) On Windows XP: Navigate to C:\Documents and Settings\All Users\Application Data\Carlson Software\Carlson2010 (or/and Carlson 2011) folder.
On Windows Vista or 7.0: Navigate to C:\ProgramData\Carlson Software\Carlson2010 (or/and Carlson 2011) folder.
Some of the folders in this path are hidden so you may just need to copy/paste this path into the Explorer window or enable display of hidden folders.
2) This folder will contain one or more sub-folders. For each of the sub-folders starting with R18.0 or R18.1, please repeat the following steps:
3) Download and save, overwriting the existing files, the following tow files:
http://update.carlsonsw.com/upload/file.php?id=6584&ps=ix1zo3j17g
http://update.carlsonsw.com/upload/file.php?id=6583&ps=gd4w4vsx2a
as a check, you should be seeing the existing files with the same name there and overwrite them
4) It is now safe to launch the program as usual

If you did not receive this email in time to prevent the loss or the menu was still replaced, please follow these steps:
1) On Windows XP: Navigate to C:\Documents and Settings\Your user name\Application Data\Carlson Software\Carlson2010 (or/and Carlson 2011) folder.
On Windows Vista or 7.0: Navigate to C:\Users\Your user name\AppData\Roaming\Carlson Software\Carlson2010 (or/and Carlson 2011) folder.
Some of the folders in this path are hidden so you may just need to copy/paste this path into the Explorer window (adding your user name in the process) or enable display of hidden folders.
2) This folder will contain one or more sub-folders. For each of the sub-folders starting with R18.0 or R18.1, please repeat the following steps:
3) Change into R18.0* or R18.1* sub-folder, then SUP sub-folder and finally BACKUP sub-folder.
4) Locate cs10base.cuix or cs11base.cuix in BACKUP folder and copy it into the SUP (one folder above) folder.

Made by who?

I get a lot of questions and often times I get the same ones over and over. One of my favorite things is to hear a myth or a misconception on a topic about which I know the truth, or at least more of the story. In this small industry it is so easy to have a piece of information disseminated to the public only to have it interpreted incorrectly. Often times this is done unintentionally and is simply a breakdown in communication or a simple misunderstanding.

One of the latest bits of confusion is on data collectors. While the questions and the answers have little impact on what I do, they are questions that I am getting more of lately so I wanted to push this out there to try to help answer the questions, dispel the myths, or simply shed new light on the topic.

Many of us are familiar with the Allegro line from Juniper Systems.  The Allegro has been around for a long time and has been a recommendation for Field Genius and SurvCE over the years.  Leica also had a radio built in to the Allegro so users could power their Robotic Total Stations with SurvCE.

We were next introduced to the JettCE from Two Technologies.  This unit was branded and labeled for various companies so you saw it around in bright colors such as orange and blue and yellow and black.  Over the years we saw variations on that box with new names and new layouts, but essentially they were all JettCE devices from Two Technologies.

Now, here is where the confusion seems to come in.  We have been introduced to the FC2500 from TopCON and the Surveyor + from Carlson Software.   The Surveyor + line is produced by Juniper Systems and the FC 2500 by Two Technologies.  Both companies went to the manufacturers and designed these units from the ground up with their own specs for ruggedness, durability, function, and performance.

You will still see forms of the Allegro and the JettCE around and available, but it is hard to compare those models to their newer relatives the FC2500 and the Surveyor+.  As I said before, this really does not affect or impact what I do on a daily basis but it is something that has come up more than a few times recently and worth getting out there.

For more information on any of these products including specifications or where to buy visit the websites listed below.

Two Technologies
Juniper Systems
TopCON
Carlson Software