How are you getting your height measurements ? (for buildings / roofs)

[mmddmmdd]

Hi folks,

How are you getting your height measurements ? (for buildings / roofs)

One option is going through the Drone deploy browser and drawing lines on 2d.

An auto cad option ? (measuring height in point cloud of auto cad looks tedious)
Virtual Surveyor has a height measurement tool, but I don't think many clients will want to download / use it.
(I guess I could)

Pix 4d only offers a height range, correct ? (would love if they had the same interface as Drone deploy)

thank you in advance for any replies, even if they run tangental.

 

[doktorinjh]

Are you trying to figure out the height of a building (AGL)? In Pix, you can get the height of the ground and the height of the object from the point cloud. I would suggest running a dense cloud and not using the automatic tie points for better accuracy. You'll want to have some GCPs for accurate results as well.

 

[Richard R]

You can load the DEM tiff file that, for instance, MapsMadeEasy generates into QGIS and then use the profile tool to generate graphs showing profiles, heights and distances. I capture the profiles and load the cvs file into Excel to generate charts that can be given to clients.

 

[mmddmmdd]

Thanks folks, trying to work this out for solar installers. there roofs can have 20 different height hVacs (14 acre roof). a "roll over" browser like drone deploy would be second best, an easier than point cloud read in auto cad would be 1st best. in QGIS, would the read out not be similar to pix4d, where it shows all the different elevations, but tough to say this HVAC (AC UNIT) is 3.6 feet off the roof, (and then 20 hvacs later...)
sorry. ask again.
1. can QGIS be used to measure heights of many different things or is it a general height plane, like pix4d, saying these hvacs are between 3ft and 3.2ft ?
2. is there any browser like drone deploy where one can read heights ?

 

[Richard R]

Heres a screen shot from QGIS. the map is in the upper section, where the red line is the line shown in profile in the lower section. In realtime, you can run the cursor alongtheu line and read out the elevations. the profile can also be dumped as a CVS file that you can read into programs like Excel. Interested in a different are, just draw another line and generate a new profile.

 

[Richard R]

Ok, the red line apparently doesnt show up. it was drawn across the second set, from the bottom, of AC units on the roof.

 

[mmddmmdd]

looked for more than a bit, cant find profile tool.
your input was DEM tiff ?
thank you much for the replies btw !

 

[Richard R]

Profile tool isn't part of the basic QGIS package. You'll have to download it and install it. Yeah, the dem tiff. I did a recolor so the shape show better.

 

[r62ewa]

The only issue I find with QGIS is I wish there was more informative Help description like in ArcGIS for what the tool is doing and what all parts of the tool are doing. I have just installed and gave it a try on one of my datasets and don't quite understand the choosing of band and what that identifies? Seems that band 2 is giving a more accurate of the terrain I am profiling, my profile seems quite erratic compared to yours.

UPDATE: I found my issue was I had downloaded and was using the Colorized DEM GeoTIFF and this was giving me strange profiles, once I downloaded the DEM (TIF) the profiles are now correct.