I wanted to ask how to get the approximate terrain slope of the area and what value are you supposed to put in the input box. Is it a percentage or in metres or centimetres?
The only way is you must understand the general profile of the terrain in your area, topographic maps also can be used. For the second question, slope is in percent or degrees,
@@GEO2004 Ok thank you for the clarification. So I looked it up online and I wanted to clarify whether this approximate terrain slope is also called elevation grade (with a mathematical formula of (Rise / Run) * 100 to get a percentage approx terrain slope). Secondly, if I have a elevation histogram of the area I am using (LidarHistogram in WhiteboxTools plugin in QGIS), can I use it to calculate this approx terrain slope?
Good afternoon, I have a DSM product from Drone photo processing, I would appreciate if you know the parameters to process and build a Qgis DTM, I have practiced with the explanation of this video, but after the process there are gaps on the edges of the vegetation and the vegetation are still there with the height of their foliage and I don't know how to remove this part of the DSM English is translator, I speak Spanish, I hope my question is understandable, thank you very much
As I already mentioned in the video or in another comments, this method will not perform very good for uav data, I guess you should stick to drone processing software like agisoft, menci, pix4d or any other. They have good point clouds classification tools that can be used for dtm generation
@@GEO2004 Thank you very much, after asking you, I continued investigating other sources and I found this document that seems very successful for what I was looking for and very similar to the procedure that you use with a few more steps. "DEM Generation based en UAV Photogrammetric" www.scitepress.org/Papers/2016/59184/59184.pdf
Doctor, please tell me how to convert qgis hackable b spectral band satellite visuals into a format. gpr. Or ert, of course, after I make the corrections, so that I can make models under the surface to study the structures and remains of ancient buildings buried under the sands using the Qgis program. Please tell me, I specialize in the study of civilizations and antiquities
@@GEO2004 How do I display Landsat images with items 10 and 11 refractories, laos, or others in gpr format. With the Qgis program, I mean, in a way that I know the location of the remains of archaeological buildings buried under the surface of the earth
Can you share how to calculate the approx slope terrain? my DSM file is very vary, there is a hills and some buildings, when I use dtm filter, the removed object just the edge of the vegetations and the buildings that removed.
For your information, this method doesn't really works if you have very detail/large scale DSM, because the algorithm is only remove certain slope (according to the slope setting), and for detailed DSM, an object can have various slope ( building roofs and walls will have different slope value), so your result is just what the algorithm can do. If you have the DSM in point clouds format, you better using point clouds classification (global mapper has such tool) to remove the building and vegetation.
dtm filter it doesnt work :( I have the same qgis version. It just says de following message: The following layers were not generated correctly. You can see the "Registry Message Panel" in the main QGIS window to find more information about the execution of the algorithm.
have you try QGIS 3.4 madeira?, may be the updates will fix your problem, I also must admit that SAGA modules in QGIS is not always perform stable. Sometimes it generate random error, may be you can try using other kind of DSM, just to make sure that the problem lies on the software and not your data
that is inferred from my general knowledge about the terrain of study area (not too scientifically sounding thru), it was based on deduction, if you had better or more precise way to infer the slope, that would be better.
@@GEO2004 I got your point, but what I need is scientific method to find that particular number for my study area. I generated slope raster in Qgis but it was in range between 900 to 2000000 (approx). What will be the percentage slope here then.
What?! Is there any flat terrain in your study area? Seems your calculation is wrong. I rarely using qgis these days, but I think qgis should be able to calculate slope in percent rise.
one way to fix if the DTM result still have "holes" and "gaps" : ruclips.net/video/zTqb6E_kkNw/видео.html
I wanted to ask how to get the approximate terrain slope of the area and what value are you supposed to put in the input box. Is it a percentage or in metres or centimetres?
The only way is you must understand the general profile of the terrain in your area, topographic maps also can be used.
For the second question, slope is in percent or degrees,
@@GEO2004 Ok thank you for the clarification. So I looked it up online and I wanted to clarify whether this approximate terrain slope is also called elevation grade (with a mathematical formula of (Rise / Run) * 100 to get a percentage approx terrain slope). Secondly, if I have a elevation histogram of the area I am using (LidarHistogram in WhiteboxTools plugin in QGIS), can I use it to calculate this approx terrain slope?
1. yes, you are right
2. yes, histogram can also used as the approximator of slope
Professional!
Thank you so much
Thank you so much for this!!!
You are welcome
Good afternoon, I have a DSM product from Drone photo processing, I would appreciate if you know the parameters to process and build a Qgis DTM, I have practiced with the explanation of this video, but after the process there are gaps on the edges of the vegetation and the vegetation are still there with the height of their foliage and I don't know how to remove this part of the DSM
English is translator, I speak Spanish, I hope my question is understandable, thank you very much
As I already mentioned in the video or in another comments, this method will not perform very good for uav data, I guess you should stick to drone processing software like agisoft, menci, pix4d or any other. They have good point clouds classification tools that can be used for dtm generation
@@GEO2004 Thank you very much, after asking you, I continued investigating other sources and I found this document that seems very successful for what I was looking for and very similar to the procedure that you use with a few more steps. "DEM Generation based en UAV Photogrammetric" www.scitepress.org/Papers/2016/59184/59184.pdf
@@dariorestrepo3494 nice, thank you for the info, I am going to dig the document too
@@GEO2004 thanks to you, your video warned me that it was possible
great video. Thanks for sharing. Good explanation too
Glad it was helpful!
Doctor, please tell me how to convert qgis hackable b spectral band satellite visuals into a format. gpr. Or ert, of course, after I make the corrections, so that I can make models under the surface to study the structures and remains of ancient buildings buried under the sands using the Qgis program. Please tell me, I specialize in the study of civilizations and antiquities
Sorry, I didnt understand your question,
@@GEO2004 How do I display Landsat images with items 10 and 11 refractories, laos, or others in gpr format. With the Qgis program, I mean, in a way that I know the location of the remains of archaeological buildings buried under the surface of the earth
I have told you, landsat cant penetrate the earth surface, no matter which bands are used,
@@GEO2004 What images can do that
I dont know, I am not an underground mapping expert, sorry.
I already have dtm files from surpac software how can I import it to qgis
It is important for me thanks in advance
If surpac can export the dem into geo tiff format, you are good to go,
Can you share how to calculate the approx slope terrain? my DSM file is very vary, there is a hills and some buildings, when I use dtm filter, the removed object just the edge of the vegetations and the buildings that removed.
For your information, this method doesn't really works if you have very detail/large scale DSM, because the algorithm is only remove certain slope (according to the slope setting), and for detailed DSM, an object can have various slope ( building roofs and walls will have different slope value), so your result is just what the algorithm can do. If you have the DSM in point clouds format, you better using point clouds classification (global mapper has such tool) to remove the building and vegetation.
dtm filter it doesnt work :( I have the same qgis version. It just says de following message:
The following layers were not generated correctly. You can see the "Registry Message Panel" in the main QGIS window to find more information about the execution of the algorithm.
have you try QGIS 3.4 madeira?, may be the updates will fix your problem, I also must admit that SAGA modules in QGIS is not always perform stable. Sometimes it generate random error, may be you can try using other kind of DSM, just to make sure that the problem lies on the software and not your data
@@GEO2004 is it necesarry to give previously the ground class and non-ground class to dsm? I thing that my dsm have not that information.
@@semimonkey6144 nope, the algorithm just use slope as the parameter
@@GEO2004 I was having the same problem, but just pulled down 3.10.2 and now the dtm filter is working again.
How can we find terrain slope percentage? Like you inserted this as 5%, how you got this number?
Anyone please answer!
that is inferred from my general knowledge about the terrain of study area (not too scientifically sounding thru), it was based on deduction, if you had better or more precise way to infer the slope, that would be better.
@@GEO2004 I got your point, but what I need is scientific method to find that particular number for my study area. I generated slope raster in Qgis but it was in range between 900 to 2000000 (approx). What will be the percentage slope here then.
What?! Is there any flat terrain in your study area? Seems your calculation is wrong. I rarely using qgis these days, but I think qgis should be able to calculate slope in percent rise.
@@GEO2004I checked that percentage checkbox.
Yeah something is wrong.
Can I get your mail address to share screenshots with you?
Thanks
mappingsince2004@gmail.com
Dear sir, how to download this DSM?
Get it from earthexplorer.usgs.gov
@@GEO2004 it is Alos DSM 30m?
Thanks for sharing
Gracias!!!!!!