Laser Scanning - A Guide to Good Practice

I want to share this link:

http://guides.archaeologydataservice.ac.uk/g2gp/LaserScan_Toc

In this guide you will find the significant information of archaeological documentation with laser scanner systems. Other survey methods were introduced in this tutorial as well. Have fun! :)

The International LiDAR Mapping Forum 2010 - Denver, USA

"How LiDAR is being used in Haiti

A new last minute addition to the International LiDAR Mapping Forum conference program will include two presentations on how LiDAR is being used in Haiti to assess the damage from the recent earthquake and the future probability of subsequent earthquakes.

Imagery of the region damaged by the M 7 Haiti earthquake, including high-resolution photography and airborne LiDAR, has revealed a variety of ground failure that resulted from shaking. Surprisingly, the Enriquillo Fault seems to have not ruptured at the ground surface, so the negative result obtained from imagery has significant implications. The USGS issued a statement, based on imagery analysis, that because it is clear that the rupture of the Enriquillo Fault was clearly farther west than Port-au-Prince, and because rupture was buried deep on the fault, there is a significant risk of not only regular aftershocks, but also the threat of a subsequent large event that could occur even closer to Port-au-Prince. The probability of one or more subsequent earthquakes of M 7 or greater increased by about 3% for the 30 days following 21 January 2010. Although this is a low probability, it would be a potentially very high impact event. High-resolution imagery was crucial to this assessment." - source: www.lidarmap.org

Program: http://www.lidarmap.org/conference/ILMF10_ConferenceProgram.pdf

New Book: Airborne and Terrestrial Laser Scanning

"Written by a team of international experts, this book provides a comprehensive overview of the major applications of airborne and terrestrial laser scanning. The book focuses on principles and methods and presents an integrated treatment of airborne and terrestrial laser scanning technology."


link: http://www.librario.com/2472

The new Trimble CX scanner

The announcement was made at World of Concrete 2010.

This high-accuracy sensor captures more than 50,000 position points per second - enough data to record the details of a target's shape, size and position.

More Information: http://trl.trimble.com/docushare/dsweb/Get/Document-479635/022504-111_Trimble_CX_DS_1109_LR.pdf

Airborne and Terrestrial Laser Scanning and geomorphology: possibilities, problems, and solutions

New Congress in Vienna:

European Geosciences Union
General Assembly 2010
Vienna, Austria, 02 – 07 May 2010

On this general assembly: "Airborne and Terrestrial Laser Scanning and Geomorphology" The session number is GM 2.2

"....Terrestrial Laser Scanning (TLS) is also increasingly applied for fast data capture of the surface, e.g., in detection and monitoring of mass movements and in other geomorphic studies requiring high accuracy and frequent repetition.
The application of both laser scanning technique results in data sets characterised by enormous data sizes, extremely high accuracy (up to cm-scale) and very high resolution. These properties compensate for the efforts invested in the data processing, however it means new challenges for the geomorphic evaluation. The wealth of laser scanning-derived DTMs can be used for geomorphic analyses in various forms (point cloud, TIN, grid) for analysis in flood-endangered regions, for natural hazard analyses like mass movements and are almost unbeatable in surface modelling of mountainous and karstic areas. They are also highly applicable in environmental change studies concerning the change in snow and ice coverage, soil creep, etc....."

Link:

http://meetingorganizer.copernicus.org/EGU2010/session/3080

Michael Jackson's 3D Body Scans on eBay for $1.5 Million

That was a great idea in 1996. However, I am astonished by it since 3d scanners were not too wide spread in the 1990's.

Link: http://gizmodo.com/5407507/michael-jacksons-3d-body-scans-on-ebay-for-15-million



Wishful thinking; Imagine there is a company to scan recent singers and other stars for movies and production in the future.

Full-waveform ALS workshop - Principle of Full- and Online Waveform Analysis in Airborne, Mobile and Terrestrial Laser Scanning

Second presentation was from Riegl Company. I already wrote about Riegl VZ-400 scanner, here we heard some Online Waveform Analysis applications....

Dr. Andreas Ullrich, DI Peter Rieger: Principle of Full- and Online Waveform Analysis in Airborne, Mobile and Terrestrial Laser Scanning

Overview:

- Introduction
- Laser Scanner RIEGL LMS-Q680 for Full Waveform Analysis
- Full Waveform Analysis and Online Waveform Processing
- Full Waveform Sample Data
- Multiple Time Around Technique
- RIEGL V-Line Laser Scanners with Online Wavefrom Processing
- Calibrated Reflectance
- Multi Target Capability
- Online Waveform Sample Data

14. International Congress "Cultural Heritage and New Technologies" - Vienna

TerraFormatics will be there! You will find some fresh news on our blog!

Workshop 14 will be held
from November 16th to November 18th 2009 in Vienna, CITY HALL (Rathaus der Stadt Wien)

MAIN TOPIC 2009:
ARCHIVING - or building an information system

Archiving is today central to nearly all aspects of Cultural Heritage Management.
Archives (Archaeological excavations, libraries, documents, data collections,...) are important data repositories.
The data contained in correctly treated and accessible archives makes wide and varied information available.
How can archiving in all its aspects best promote knowledge about and support the protection and conservation of cultural heritage?

Link:

http://www.stadtarchaeologie.at/

Riegl VZ 400

Let me introduce the one of the best TLS system... I wrote already about this scanner. Last winter I met with Riegl VZ-400, you can control it with an iphone....amazing stuff...




"The new RIEGL VZ-400 3D Terrestrial Laser Scanner provides high speed, non-contact data acquisition using a narrow infrared laser beam and a fast scanning mechanism. High-accuracy laser ranging is based upon RIEGL’s unique echo digitization and online waveform analysis, which allows achieving superior measurement capability even under adverse atmospheric conditions and the evaluation of multiple target echoes. The line scanning mechanism is based upon a fast rotating multi-facet polygonal mirror, which provides fully linear, unidirectional and parallel scan lines. The RIEGL VZ-400 is a very compact and lightweight surveying instrument, mountable in any orientation and even under limited space conditions."

www.riegl.com/products/terrestrial-scanning/produktdetail/product/scanner/5/

www.riegl.com/uploads/tx_pxpriegldownloads/10_DataSheet_VZ400_10-09-2009.pdf

Geography and LiDAR

researches at forest areas are a very popular part of the LiDAR know-how....

One of my favorite paper is from ISPRS Laserscanning '09.....very useful and innovative ideas, we need that kind of work, and not the discussions of RMS faults....how can I correct another mm-s....


A DECIDIOUS-CONIFEROUS SINGLE TREE CLASSIFICATION AND INTERNAL
STRUCTURE DERIVATION USING AIRBORNE LIDAR DATA
C. Ko, G. Sohn, T. K. Remmel

"ABSTRACT:
This project has two main purposes; the first is to perform deciduous-coniferous classification for 65 trees by using the leaf-on single flight LiDAR data. It was done by looking at the geometrical properties of the crown shapes (spherical, conical or cylindrical), these shapes were developed by a rule-driven method Lindenmayer Systems (L systems). Two more parameters that are data driven (convex hull analysis and buffer analysis) were developed to further capture the geometrical differences between deciduous and coniferous trees. Proposed methods are scale independent and arithmetically simple, they were developed simply by looking at the geometrical differences between the two types of trees. The classification rate was cross-validated and trees are 85% - 88% correctly classified. The second part of the project is to derive the internal structures of the LiDAR tree according to the results obtained from the first part. Internal structures include bole and branches; the location and orientation of the bole was done by connecting the geographic centres of horizontal slices of the tree. The branches were derived by k-means clustering techniques, different types of trees will yield a different type of branching structures for better visualization.

DISCUSSION / CONCLUSION
There are two major types of LiDAR systems for research and commercial use, full waveform and discrete returns. This paper has used only the discrete returns of the range data, and by studying the geometry of the crown shape properties, we classified the different crowns into two major classes, deciduous and coniferous. From the classified results, bole and branching structures were reconstructed according to the type of tree. The shape of the tree crown is inherited in the gene (adaptation) and therefore a certain species will have the similar crown shape and branching structures. The other factor affecting crown shape and branching structure is the growing strategies, which is adopted by the growing neighbour environment and those are more difficult to model (Horn, 1971). As a result, crown geometry is believed to be an important piece of information for species classification. By using just the three geometrical shapes (sphere, cone and cylinder), results were improved from 65% to 67% when the outliers were removed. If other parameters are included (area to volume ratio of convex hull and point to polygon buffering analysis), results were improved from 85% to 88%. Using crown shapes to classify trees is an intuitive method, but in this study it did not show promising results. By looking at the other geometrical properties, the results for classification increased considerably. Although different from what was expected, it is still believed crown shape and internal structure are good indicators for classifying trees, and future studies should be conducted in this direction. This method of classification is quite simple to produced and arithmetically easy. Tree bole and branches reconstructions are for visualization, but can also be used to study growth behaviour and to provide insight regarding why trees grow in a particular directions. These results are useful in many types of studies. For example, it can be used to study the potential hazards of a tree growing into structures, by classifying trees into deciduous and coniferous provide a better growth estimates."

NEWS: Leica ScanStation C10 - the next-generation Laser Scanner

"Heerbrugg, — September 07, 2009 — Leica Geosystems announces the completely new Leica ScanStation C10, the company’s biggest leap forward yet in laser scanners for as-built and topographic surveys....."

I never worked with Leica TLS system, this scanner seems very improved. But....I think without waveform analysis I don`t want to buy it... :)

One of the most impressive TLS today: Riegl VZ-400 (later new topic about this system)

http://www10.giscafe.com/nbc/articles/view_article.php?section=CorpNews&articleid=735825
http://hds.leica-geosystems.com/en/79411.htm

ISPRS Workshop Laserscanning 2009 I.

Hallo everybody,

Wednesday finished the ISPRS Laserscanning 2009 in Paris.

Thank you, congress was very professional!

160 people were from 25 countries at the workshop. 31 presenters, extra 4 company presentations and 27 posters were in the program.

31 presenters were from 13 countries. Iran and Greece cancelled.

(Country, number of oral presentation)

Austria	3
Canada	3
Finland	4
France	4
Germany	6
Greece	1
Iran	1
Italy	2
Japan	1
Netherlands	3
Swiss	1
Spain	1
UK	1

Two areas (forestry, urban) are very popular in the LiDAR researches, where the newest papers were presented on the week.

I think, the most interesting topics were:

Automatic classification and feature extraction

TLS calibration

Photogrammetry and LiDAR combination

Analysis and visualisation with Voxel

Usage of LiDAR Intensity information

I want to write more details on the next days about these topics and the papers.

Laser Scanning Brings New Asset to Accident Investigations—and Surveyors

"Laser Scanning technology is revolutionizing many aspects of surveying and applied measurement, but it's been especially game changing in the rarified niches of forensics and accident investigation. The main strengths of scanning--speed, safety, accuracy, comprehensiveness, and the ability to return to the same data set and make new observations--serve forensic engineers especially well. Money is also a factor: when so much is riding on a court case, the extra costs associated with adopting new technology don't seem especially significant....."





I hope we will see some TLS documentation in the following Dexter episode`s..... :)

http://www.amerisurv.com/PDF/TheAmericanSurveyor_Longstreet-ScanningAccidents_August2009.pdf

iTacitus

Augmented reality is a buzzword nowadays, and iTacitus is just about that. AR + tourist information, to be precise.

It would be interesting to see that in action, I'm curious, how fast will it spread.

On the other hand, it would be nice to see some AR applications while scanning an area! For instance, you could upload a part of the scanned points on your phone, and an AR software could show you, which parts of the area have been scanned already. The problem is, that you need instant GPS data for that, and you have to merge the different scanning position datas instantly. Without a specific software it could be quite difficult to do that.

However, links for iTacitus:
http://itacitus.org/
http://itacitus.org/content/blogsection/5/38/

Sig.ma

Sig.ma is a visual browser and meshup generator, which will crawl the web for informations, semantic data, and even search inside applications.

You can get some information about laserscanning at this link: http://sig.ma/search?q=laserscanning (A nice start to get familiar with Sig.ma)

However, I find this tool rather interesting than useful. At least for now.... semantic web is the future.

Nanoscanning

http://www.sciencedaily.com/releases/2009/08/090816171003.htm

"Researchers have created the tiniest laser since its inventien nearly 50 years ago, paving the way for a host of innovations, including superfast computers that use light instead of electrons to process information, advanced sensors and imaging." And so on, and so on...


Even if I will not work with nanolasers, spasers, or whatever that comes out from the gates of modern science, I'm happy about hearing the news. In time, it will have a positive impact on TLS, laser scanning in the real world. (Well, not that blood cells are not real, but I can't touch them. Scanning a bridge or statue is more of a 'handleable' work, for me at least.)

But: we are using the same 'technology', the same softwares, and we have more or less the same issues. (How will they solve the scanning of a fast moving bacteria, for instance? How can we scan the waving water, or the trees blown by the wind?)

And for the softwares: we are using the same technique for imaging and manipulating the datas. After all, they are just numbers. Scale doesn't matter, we have invented the normal form already. So, if nanolasers mean that the number of engineers working on the field will double, I suppose the efforts for developing softwares will double as well.

It would be nice to see that progress in the near future.

Capturing 3D Surfaces Simply With a Flash Camera

http://hothardware.com/News/Capturing-3D-Surfaces-Simply-With-a-Flash-Camera/

This is from August of 2008. I'm curious, where did they get from here..

Sexy Data

Recently I read a blogpost about the sexyness of handling huge datasets, being a statistican, etc.
You can find it here:
http://dataspora.com/blog/sexy-data-geeks/

I have some words to add, according to TLS.
It's quite nice to work with geodata.. For instance I was always impressed by sat images. (And everyone likes google maps.) Working with 3D pointclouds (of real buildings, statues, terrain, whatever), and making them useful is an interesting job.

Now to Data Munging: we have previous posts about working with coordinates (awk, especially), but thats only tip of the iceberg. You have to clean the 3D point cloud, remove not static objects (for instance cars and people on a street), take care about the correctness of the coordinates (1-2cm difference between two intersecting pointcloud is an everyday issue), uniting the intersecting point clouds to a bigger one, etc.

And yes, Visualisation. After creating a 3D model, you can put the real texture on it, with the help of some HD photos. After that you have a really nice object model. And thats just where the work starts!

After reading the beforementioned post, I've had the feeling that working with laser is sexy as well..

3D projection on buildings

The opposite of TLS:
http://vimeo.com/4238052

Zurück in die Tiefe!

Was ich sehe, abtaste, kann ich gleichzeitig in einem virtuellen Raum darstellen. Speichern. Ausschalten.

Was machst du...?
Die Rohdaten verarbeiten. Modell erstellen. Die Frage ist immer gleich..... ob die Ergebnissen richtig und vollstandig sind........
Wenn man z.B. eine neue Filterung wahlt, der Abstand zwischen den Punkten ist anders, so bekommst du neues Modell bei der Vermaschung........ Visualisierung ist eine Art der Dokumentation, was man in Zukunft verwenden kann. Wie z.B. ein Gemalde aus dem 18. Jahrhundert über ein Gletscher, mit wem der frühere Zustand rekonstruierbar ist. 3D-Modell ist ahnlich wie ein Gemalde, nur bei dem Zeitraum (und so bei der Technoligie) findet man den Unterschied......:)

Nachstes mal reisen wir aus die tiefe Grube in die Höhe, wo "Herr Eis" lebt.....:)







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