GlobalMapper_PL_EN

Questions Log - GlobalMapper Webinar 2012_01_12 17_05

Audience Question:
Q: When you combine multiple terrain layers that have different resolution, does it automatically honor the higher res data where it exists? or does it matter which is on top?
A: Global Mapper will use whichever terrain layer is on top ata  given location. So you would typically load your lower resolution data first, then the higher resolution data on top.

Audience Question:
Q: does turning off the feathering speed up the refresh display?
A: Yes feathering does slow things down slightly, although it's usually not noticable unless you are feathering to a complex polygon rather than just simply the edges.

Audience Question:
Q: Sam mentioned a "drape" option. How is that function accessed?
A: The 3D function automatically drapes whatever you see in the 2D view on the terrain surface. You don't have to do anything to enable it, it just works!

Audience Question:
Q: When will global mapper be able to make profiles over LIDAR cloud point data?
A: Currently you can do it already just by creating an elevation grid from the Lidar point cloud then do a profile like Sam is showing now. Eventually you will be able to do one from the point cloud itself though and extract some different information that having a point cloud allows.

Audience Question:
Q: Is it possible to export the path profile data (eg. to Excel)?
A: Yes, on the Path Profile dialog there is a File menu with several export options, like a distance/Z files with the distance and height. That would load right into Excel as would some of the other options.

Audience Question:
Q: Is there a way to calculate slopes within a specific range (eg 0% to 2%) from a DEM?
A: I think Sam might show this later, but yes if you select the Slope Shader on the toolbar you can see the slopes visually. You can setup the coloring based on the slope on the Shader Optoins tab of the Configuration dialog.

Audience Question:
Q: How does Global Mapper handle time or depth
A: Line features in Global Mapper can have per-vertex elevation/depth values as well as per-vertex time values (like from a track log). You can add/edit these on the Vertices dialog for a line feature accessible from the Feature Info dialog or the edit dialog for the feature.

Audience Question:
Q: do you have the link to download elevation data for Canada for free?
A: The ASTER GDEM data set on the File->Download Online Imagery/Data dialog includes the entire world at 1.5 second (about 45 meter) resolution. You might also get CDED terrain files for Canada from http://geobase.ca.

Audience Question:
Q: Could we use google earth images on top of SRTM or DEM?
A: While you can't directly access Google Earth (that would violate Google Terms of Service), you can use File->Download Online Imagery/Data and pull in imagery sources that are comparable and in some case better than Google Earth, or of course load your own data files from whatever files that you have.

Audience Question:
Q: Can Global Mapper handle subsurface data as in depth structure maps to produce 3D models ???
A: If you have 3D vector data (i.e. areas, lines, and/or points with elevation/depth data), then you can view them in space in the 3D view. Doesn't matter if the height values are positive or negative.

Audience Question:
Q: Why is the elevation in metres and the horizontal in miles re: the bridge profile?
A: The units settings for the elevation legend and the distance scale are separately configurable. You can right-click on either one and select the units, or choose units on the General tab of the Configuration dialog.

Audience Question:
Q: Is it possible to assign slope to road data?
A: You can assign per-vertex elevations to a road on the Vertical dialog for the line (accessible from the Feature Info or Digitizer Tool), then show those in 3D view. If you have a road that already has per-vertex elevations you can select that line (or multiple lines) with the Digitizer Tool then right click and select to calculate/add elevation stats. Then you can get information like the average, minimum, and maximum slope and elevation for the line.

Audience Question:
Q: how did Sam bring in the roads to terrain view?
A: He loaded a .shp file with the roads using the File->Open Data File menu command. Numerouse vector formats are supported.

Audience Question:
Q: Sam, could U present to the audience a water on the Path Profile, since tis option is already available in GM.
A: Looks like he got it on the 3D view, not sure if he will show on path profiile.

Audience Question:
Q: Will COAST, the computer program mention in MPBN's radio piece (http://www.mpbn.net/Home/tabid/36/ctl/ViewItem/mid/3478/ItemId/19547/Default.aspx) be incorporated into GM?
A: We are planning on adding additional flood planning and hydrological analysis functionality in future versions of GM.

Audience Question:
Q: Where is LIDAR data available?
A: There isn't really a single repository for Lidar data, usually you get it from either a custom flight or some states have Lidar data available.

Audience Question:
Q: Applications to the petroleum exploration industry?
A: There are many petroleum applications. What Sam is showing now is applicable to pad site placement for a drilling operation.

Audience Question:
Q: we have many shp-polygons and would like to know the cut and fill of the raster under these polygons. is there any method to do this in one operation on multiple polygons and write it to a polygon attribute or in a list?
A: Yes if you select multiple areas with the Digitzier Tool you can right-click and choose the same Measure Volume item just demonstrated and calculate volumes for all of the areas at once.

Audience Question:
Q: is there a glossary of terms we can reference?
A: I'm not aware of a good one, but Sam might know off-hand when he is done.

Audience Question:
Q: is it possible to draw a rectangle polygon from left bottom corner to right top corner, not from the middle center?
A: Yes hold down the 'T' key to hold down to enable top-left to bottom-right drawing. See http://globalmapper.com/helpv13/Global_Mapper_Shortcut_Key_List.pdf for a list of shortcut keys.

Audience Question:
Q: Where is a good place to get elevation data in the London England area
A: The File->Download Online Imagery/Data menu command would include ASTER GDEM and SRTM data for that area. For high resolution (i.e. 5m resolution) the premium Intermap terrain source also cover England.

Audience Question:
Q: if you are digging a ditch below surface, why do you have to fill volume?
A: Sorry I missed exactly what Sam did answering questions, but part of the cut surface must have been above the surface.

Audience Question:
Q: I have GM v.12, but v13 is the most recent version. What features demonstrated during today's webinar require that version?
A: The watershed generation being demonstrated now is much much faster in the upcoming v13.1 release than in previous versions, especially for large areas. There are also a lot of additional built-in online sources in the upcoming v13.1 release and a ton of other features. There will likely be a webinar specially for demonstrating the new features when the new release is ready.

Audience Question:
Q: Inside of lake areas, why do the watershed lines persist?
A: Just from the terrain it's hard to tell where lakes are because the terrain model usually has the lakes flattened out so it only sees a flat surface there.

Audience Question:
Q: I'd like to create a watershed by defining a particular outlet point along a stream, then determining shape of the upstream watershed. Is that possible in GM v12 or v13?
A: Yes, select the point with the Digitzier Tool, then do the watershed and on the watershed dialog there will be an option to see the flow to the selected point(s).

Audience Question:
Q: Is it possible to create dem from a contour shapefile?
A: Yes, simply right-click on contour layer in Control Center and select to create elevation grid.

Audience Question:
Q: I'm interested in the cut-and-fill function. I have nextmap dem, but can't open the 3d view to view it
A: What version are you using? Does the nextmap DEM show in the normal 2D view as a terrain layer? You can email gmsupport@bluemarblegeo.com offline for support.

Audience Question:
Q: How about for identifying geology?
A: You can certainly load geology maps for display and there are special tools for adding strike-and-dip points and such.

Audience Question:
Q: for the 3d view: does the cellsize of the elevation grid and the orthophoto need to be the same and with the same origin?
A: No, they don't even need to be the same projection. Global Mapper automatically handles this for you.