Here I go (again), sailing off into uncharted waters and I find myself appealing to the surveyor brain trust.
In 2011 and 2012, our local government in cooperation with a number of federal and state agencies flew and collected LIDAR and aerial imagery on 3680 square miles of the area I work in. The files are being made available for a nominal fee and are composed of two sets of data. The LIDAR data contains DTM, 2' contours, Hillshades and building footprints at 97% confidence. The aerial imagery comes in 25 square mile tiles with 1/2' resolution in the core areas and 1' in outlying areas. The images are in a georeferenced .sid format put out by a company called Lizardtech.
Being a surveyor for a utility I can see a lot of potential here for mapping purposes.
What I'm trying to figure out is how to integrate the .sid imagery with my GPS/conventional surveys in TBC 2.81 for the purpose of getting contour data and general improvements into my design drawings and for improving our records maps.
I'm fairly new to TBC and I'm not a photogrammetrist nor a GIS guru. Some of this data will likely require a GIS platform like Arcview to manipulate. What I have done in the past is use aerial imagery rectified to surveyed points like guard rail bullnoses and other readily identifiable points along with ties to controling corners for general mapping purposes using LDD.
Does anyone out there have experience at this? I don't seem to be able to find what I'm looking for in the TBC tutorials. Any direction or suggestions would be greatly appreciaed.
Thanks in advance. Willy B-)
If you set your CAD program (ie C3D or LDD)up in the same coordinate system as the LiDAR DTM data and MrSID imagery you should be able to import it coordinate correct directly into CAD. Mat-Su will have published this meta-data somewhere. TBC would not be my program of choice to manipulate the things you speak of although it does support landXML and other DTM formats and possibly MrSID images. Hit "F1" in TBC. Hope that helps some.
Thanks dig. That actually did help me find the file formats that TBC can swallow. One more piece to the puzzle. I'm looking at Blue Marble's Global Mapper software to possibly parse and convert these tiles to something that will work in TBC.
I am in the process of ungrading an old version of Global Mapper to the latest ver. 14. Supposedly has enhanced LiDAR data manipulation as well as support for many raster and vector data sets.
I can't say enough good things about Global Mapper. Support is unequaled and they offer free webinars regularly that are very good.
Just a quick follow up for anyone that might follow in my footsteps. GeoExpress put out by Lizardtech is the key to manipulating, cropping and converting these files to georefreneced .tif files that can be imported into TBC. The bummer is the limitation on the size of the image files that TBC can display, but man is it slick with high resolution imagery for QC and remote mapping purposes.
