Geomatica LidarEngine FAQ

Q) Are there any tools or methodology for calculating the optimal raster cell size when generating a surface from points? In step 3 of 3 in the LIDAR processor the cell size is given a default value, how is this calculated?

A) The default cell size in the Lidar Processor is the area of the bounding rectangle divided by the number of points.

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Q) Are there any quality control tools? For example, tools that would compare the values of the original points to the value of the surface, or compare the smoothed surface to a surface?

A) LidarEngine does not have quality control tools at present. These could be developed, such as visualization of the points in 3D above and below the surface or subtraction of 2 surfaces etc.

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Q) Can I get access to all of the information in an LAS file? When viewing the LAS data as regular points (not multi-points), in the table I can see x, y, z, and a column called ‘attribute’ (not sure what this refers to). Is it possible to view the other data in an LAS file – for example, the z values for the various returns If yes, is it possible to parse data using the information in the table?

A) The values which are read from the LAS file are xyz and intensity (as the attribute). The Lidar Processor has an option to build this intensity value into a thematic layer which can then be draped onto the DTM. You need to specify the range of intensity values. This range is then mapped onto a grey scale.

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Q: How well is Lidar integrated with PCI Geomatica?

A: Geomatica and LidarEngine exist as stand alone products (you could buy LidarEngine without having Geomatica). However, Geomatica and LidarEngine’s features and functionality compliment each other in many applications.

For example:

Ortho Image Generation:
Customers looking to create high resolution DEMs from LidarEngine for import into Orthoengine can export their DEM to ESRI Grid format in LidarEngine and load this directly in to Orthoengine as the DEM source for orthorectification

Contouring:
Contours created from the Contouring wizard in LidarEngine can be used with the SMMCMASTER smoothing algorithm in Focus to create high quality vector representations of raster surface models for use in Orthoengine or Spatial Analysis.

3D Representation
User’s can import their orthorectified tiff images and DEMs into LidarEngine and take advantage of LidarEngines 3D visualization tools for display.

Currently there are a number of formats that both Geomatica and LidarEngine support to make transferring between the two packages easy. The GDB technology in Geomatica makes transferring between the packages easy.

Geomatica support formats listed here http://www.pcigeomatics.com/products/gdb_formats.html

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Q: Do you see any problems with using LidarEngine to map the faces of open cast mines for volume calculations?

A: As long as the RAW dataset entering LidarEngine represents the surface you are looking to extract, there shouldn’t be any problems with mapping open cast mines; however, this application has not been tested specifically

LidarEngine does have a volume calculation (Variability) however it may not meet the needs of these specific clients

I recommend reading the “Terrain Variability” section from the help to confirm whether this calculation is applicable to the mining application.

Geomatica Focus does have a volume calculation (VLM) algorithm that might be more applicable:

VLM - Elevation Data Volume under Bitmap

VLM uses an elevation channel stored on the database file to calculate the volume between the surface of a bitmap-defined region and a user-specified base elevation.

The volume between the surface defined by the elevation data and the specified elevation base is calculated under the bitmap mask. Note that volume can either be positive (elevation is above base elevation) or negative (elevation is below base elevation).

The total absolute volume (sum of absolute values of positive and negative volumes), the total net volume (difference between positive and negative volumes), and the positive volume, and the absolute value of the negative volume is reported.

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Q: Can LidarEngine be used to detect single trees

A: There is no specific module for doing something of this nature.

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Q: How does LidarEngine handle classified data?

A: LidarEngine currently reads the X,Y,Z, and Intensity values from a raw (TXT, LAS, XYZ) file. As such, it does not handle classified data.

If you were to read in a lidar dataset with data classified into different classes (e.g. a bare earth class and a canopy height class) it would take all the data and build a single surface from it.

The user is required to separate the classes out prior to being imported into LidarEngine. It is important that users looking for a bare earth model import a lidar dataset containing only bare earth points. Same goes for Canopy heights or data with buildings.

If one wanted to create an Above Ground Canopy height model, they could subtract the canopy heights surface from the bare earth surface. This can be done using EASI Modelling in Focus.

LidarEngine is not capable of classifying RAW data (assigning classes to raw data points).

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Q: What are some key strengths of Geomatica LidarEngine?

Data Processing	Terrain Analysis	Editing	Visualization
Point Aggregation Point Collection Contouring Grid Splicer Grid to Grid Feature Merger Georeferencing Raster Gap Filler Grid Resizer Grid Smoothing Grid Trimmer	Slope Analyzes an elevation grid and calculates the slope of each cell Aspect Analyzes an elevation grid and calculates the direction that each cell is facing Viewshed Analysis Evaluates all grid cells surrounding a viewing location and evaluates whether they are visually connected Terrain Variability Calculates the volume of material needed to be moved in order to make a user defined area flat	Selection Delete Add Polyline	Create Contours create lines or regions (polygons) generates a vector representation Labeling Annotating a feature from the map’s table Theme Editor Color profile to depict the grid representation Relief shading options 3D Viewing Drape the Point layer over the Surface layer Modify 3D perspective by rotating the image horizontally, vertically

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Q: Is LidarEngine capable of multi threading?

A: Yes, Geomatica LidarEngine is fast, and users will notice screen refresh as they manipulate large 2D and 3D raster files real time. Running multiple functions simultaneously with Geomatica LidarEngine’s multi-threaded architecture, means getting results faster than ever.

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Q: What version of Google Earth do I need?

A: To have Google Earth Launch automatically and zoom to your file LidarEngine requires that Google Earth Version 3 is installed on the host machine.

The download for Google Earth 3 is linked below:

http://earth.google.com/download-earth3.html

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Q: Does the software work on floating licenses?

A: No, LidarEngine is only available in a stand alone licensing. The licensing mechanism is presented when the product is first launched. Here you can select to license the product in Evaluation Mode or Registered Mode.

Evaluation Mode
if you are evaluating the software you will not need a License Key to install and run the product. When the Licensing dialog appears, simply choose the evaluation option, complete the customer profile and click the Activate button. The software will then contact the AmberCore license server and retrieve an evaluation license key and upload it to your system. This key will allow the software to operate in its entirety for a 30 day period beginning from the day the license was retrieved. You will be notified each time the product launched to how many days remain in the
evaluation.

If you do not have an internet connection, please see the section on Manual License Retrieval.

Registered Mode
If you have purchased Geomatica LidarEngine, you will want to choose the Registration option on the Licensing dialog. When this option is chosen you will be prompted to enter the 26 character installation key that was issued at the time of purchase. If you have not received this key please contact your sales representative. Complete the customer profile section and click the Activate button.

The software will then contact license server and retrieve a digitally signed license key and upload it to your system. This key will allow the software to operate indefinitely. If you do not have an internet connection, please see the Manual
License Retrieval section of the User Guide

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Q: What Hardware is the software available on? 32 bit? 64 bit?

System requirements:

The following list contains the recommended system requirements for Geomatica LidarEngine. In addition to these, Geomatica LidarEngine also requires that your computer system have the .NET Framework and Microsoft Direct X installed. If you are unsure if your system has these components you can install them from the Geomatica LidarEngine installation CD.

• Microsoft Windows XP (Professional or Home Edition) with Service Pack 1 or Service Pack 2, or Microsoft Windows 2000 with Service Pack 4
• 2 GHz processor
• 512 RAM
• 1024 x 768 with true color
• 100 MB of hard disk space (NTFS file system is recommended)
• 64 MB video card
• MS-Mouse compliant pointing device with scroll wheel
• CD ROM

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