Creating a planimetric map for transmission line corridor

[Anonymous]

I am currently working on a transmission LiDAR project, which requires one of the deliverables to be a planimetric map around the line route. While I am familiar with collecting LiDAR data and orthrographic imagery to make maps, I am at a loss as to how a Planimetric map is made. 

The requirements specify that the file be delivered in AutoCAD format. Is this something AutoCAD produces automatically from different types of data? What might the data product look like in AutoCAD? Any help to get me on the right track is appreciated. Google has not been particularly helpful in getting this information. 

Thanks in advance for any responses. 

[john.vellek · Accepted solution]

Hi @Anonymous,

I see that you are visiting as a new member to the AutoCAD forum. Welcome to the Autodesk Community!

 I am afraid this is beyond my expertise.  I have a basic understanding of what the planimetric map looks like but to my knowledge there is no special feature in AutoCAD that would help in creating one automatically.  I would wager that posting in the AutoCAD Map 3D , or Civil 3D forums might get you better answers than mine.

I do see a couple of add-ins in the Autodesk App Store that might be worth exploring as well.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[tboehler · Accepted solution]

This type of map can very greatly based on project phases and client requests/standards.  During the conceptual design phase we may just use an image (Google Earth Pro or USGS Quad) that will get labels for exisitng features and linework/labels for the proposed items.  For Design/Construction drawings a surveyor will supply us with a detailed planimetrics map along with topography and an image (Autocad format).

Planimetric maps by definition show all features except for terrain (topo).   Altough we normally show topo on the drawings when we are using vector based data. 

If you need data - conceptual stage data can be found on USGS websites (USGS Quads are a good basemap for conceptual stuff), state and local sites, Google Earth, more.  the client may have what you need.  You can always digitize from a photo. 

Previous post by John touched base on working in Map or Civil 3D - almost a must if you are creating maps from textual data, shp files, survey data, etc.  

Hope this helps.  

[Anonymous]

John, thank you for the welcome and your feedback. I will have to check out MAP 3D to look further. This is definitely a good start to my breadcrumb trail to solve this issue. 

[Anonymous]

Thanks for your feedback. This is really helpful! I will head over to the Map 3D forum and see if they have more info after doing a bit more digging.

[ChicagoLooper]

A planimetric map around the transmission line is merely a map that places all objects on the same plane, or where z=0. Planimetric maps do not have line work that is 'elevated' to its respective distance 'above mean sea level.'

Your Lidar data typically has x, y, and z data, i.e. a building's roof will be higher than its base footprint, tree canopy will be higher than trunk base and top of city furniture ( telepnoes poles, fire hydrants, street signs) are higher than ground level.

Since typical Lidar data provides you with enough info to draw in 3-dimensions, the requirement to draw a planimetric map is simply telling you to draw the map around the transmission lines in 2-D and not 3-D. Of course, when a map is viewed directly from above, plan view, it doesn't matter if you draw in 3-D or 2-D because your resulting deliverable will look the same. The effort involved, however, to draw in 3-D as opposed to 2-D, would be greater when drawing in 3-D. Generally speaking, there is no 'added value' to draw in 3-D when your deliverable is a plan view.   

[Anonymous]

ChicagoLooper,

Thanks for your reply. To clarify, the primary deliverable is the LiDAR of the corridor. Planimetric is the deliverble that I am not familiar with how to make. I am not sure how planimetric maps are made in the first place. Whether they are had drawn over a tiled, georeferenced map, or somehow automated most of the way, and then touched up. This is new territory for me. 

[ChicagoLooper]

Draw it in 2D, not 3D.

I would assume the 2D requirement is because the reader(s) or 'audience' cannot work with, or use 3D drawings, especially Lidar which would require a program with more horsepower than plain vanilla Cad.

It would guess your planimetric drawing would have quite a large and varied audience, i.e. county or state permit issuers, federal regulators, neighboring landowners, conservationists, surveyors, the transmission line owners themselves, subcontractors, etc., etc. (I'm sure there's more) and each of them has a responsibility to see that the transmission corridor complies with regulations, does not adversely impact adjacent property owners or the community in general, or communicates the area where construction and installation work is to be performed.  

I would think the major drawing components, besides the corridor and overhead transmission lines, would be support tower locations, right-of-way, easements, adjacent parcel lines, land use, land coverage, topography, roads that intersects the corridor, and other public utilities near or within your area's scope of work.

If all you can do with your Lidar data is to draw the corridor, lines, and towers (you can draw, right? and not just assemble and format Lidar data) then draw it in 2D and be done with it. If your drawing requires more info than that, then that's a different issue and should probably be posted separately. Alternatively, you can simply assign the drawing to someone else.

[Anonymous]

Thanks for this information. I knew the Planimetric map had to be in 2D. Something in my head led me to believe that Classified Lidar data could be taken and flattened to produce a planimetric map with the automatic features that were classified in the Lidar data. Thinking back, I have no idea where this idea came from.

For a traditionally drawn planimetric map, is it usually drawn on top of georeferenced aerial photography maps? If not, what is the basis for the geo-reference of a planimentric map?

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