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Post by sirish19 on Aug 11, 2020 21:39:05 GMT -5
I have been creating a few Japanese courses from DEM (Digital Elevation Model) data sets that are readily available in Japan as LiDAR data here is not readily available. The resolution of these data sets are 5 mesh meaning that measurements are taken at 5-meter intervals. While the courses are not perfect, some actually turn out pretty well and are "better than nothing", and certainly a good starting point for additional sculpting and fine-tuning.
I am looking at trying to build some other courses in countries where there is no data readily available (at least I can't find it) such as China or Singapore. One thought that I had was to try to extract elevation data from Google Earth and see how that might work. Depending on the area, Google Earth seems to have mapped out somewhere between 15 meters and 15 cm so it might not be too bad. Before I spend too much time trying to figure this out, I wanted to check here to see if anyone has tried that already.
So far, I have found that I can draw data points all around the golf course in Google Earth (the denser the points the higher the resolution) and save that as a KMZ file. Then if I import that KMZ file into a free online conversion tool called GPS visualizer, you can save the data as a text file giving X, Y, and Z values (longitude, latitude, and altitude).
Using some software such as GlobalMapper, ArcGIS, or potentially some free software such as QGIS, you should be able to turn that data into DEM, classify the data as ground and potentially be able to convert that into a LAS file that can then be used by Chad's tool to create the course.
Has anyone tried this? Any ideas?
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Post by theclv24 on Aug 12, 2020 6:42:37 GMT -5
I have been creating a few Japanese courses from DEM (Digital Elevation Model) data sets that are readily available in Japan as LiDAR data here is not readily available. The resolution of these data sets are 5 mesh meaning that measurements are taken at 5-meter intervals. While the courses are not perfect, some actually turn out pretty well and are "better than nothing", and certainly a good starting point for additional sculpting and fine-tuning. I am looking at trying to build some other courses in countries where there is no data readily available (at least I can't find it) such as China or Singapore. One thought that I had was to try to extract elevation data from Google Earth and see how that might work. Depending on the area, Google Earth seems to have mapped out somewhere between 15 meters and 15 cm so it might not be too bad. Before I spend too much time trying to figure this out, I wanted to check here to see if anyone has tried that already. So far, I have found that I can draw data points all around the golf course in Google Earth (the denser the points the higher the resolution) and save that as a KMZ file. Then if I import that KMZ file into a free online conversion tool called GPS visualizer, you can save the data as a text file giving X, Y, and Z values (longitude, latitude, and altitude). Using some software such as GlobalMapper, ArcGIS, or potentially some free software such as QGIS, you should be able to turn that data into DEM, classify the data as ground and potentially be able to convert that into a LAS file that can then be used by Chad's tool to create the course. Has anyone tried this? Any ideas? You lost me at DEM...
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Post by sandsaver01 on Aug 12, 2020 6:44:13 GMT -5
I have been creating a few Japanese courses from DEM (Digital Elevation Model) data sets that are readily available in Japan as LiDAR data here is not readily available. The resolution of these data sets are 5 mesh meaning that measurements are taken at 5-meter intervals. While the courses are not perfect, some actually turn out pretty well and are "better than nothing", and certainly a good starting point for additional sculpting and fine-tuning. I am looking at trying to build some other courses in countries where there is no data readily available (at least I can't find it) such as China or Singapore. One thought that I had was to try to extract elevation data from Google Earth and see how that might work. Depending on the area, Google Earth seems to have mapped out somewhere between 15 meters and 15 cm so it might not be too bad. Before I spend too much time trying to figure this out, I wanted to check here to see if anyone has tried that already. So far, I have found that I can draw data points all around the golf course in Google Earth (the denser the points the higher the resolution) and save that as a KMZ file. Then if I import that KMZ file into a free online conversion tool called GPS visualizer, you can save the data as a text file giving X, Y, and Z values (longitude, latitude, and altitude). Using some software such as GlobalMapper, ArcGIS, or potentially some free software such as QGIS, you should be able to turn that data into DEM, classify the data as ground and potentially be able to convert that into a LAS file that can then be used by Chad's tool to create the course. Has anyone tried this? Any ideas? It sounds like an interesting idea, although I have no idea how those conversions would work. It sound pretty labor intensive putting all those points down in Google Earth though; I do not think I am that dedicated. Good luck!
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Post by sirish19 on Aug 12, 2020 9:46:47 GMT -5
Haha. DEM is very similar to LiDAR where you have assigned three coordinates for each point (a longitude, latitude, and altitude) and when you have a lot of points, it creates a 3D map. LiDAR is a little more complex as it may run several scans and make an educated guess as to what is ground, what is vegetation and what is a building, for example.
As for the labor intensity of mapping out the points in Google Earth, it is actually not that hard, you just hold down the left mouse button and move your cursor around the course and it automatically lays down many points. The slower you move, the more point it puts down so if you moved around the green slower for example and faster around other areas that are less critical, I don't think it would take that long. Probably a few minutes per hole. I am pretty sure I have spent a lot more time trying to find the LiDAR data and the correct EPSG code than it would take me to map out a course.
I am still trying to figure out which free tools I can use for classification and then exporting to LAS. I know I could do it with GlobalMapper as I did all of that for the Japan data that I converted, but that was with a free trial and I don't have access to that anymore....
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Post by sandsaver01 on Aug 12, 2020 11:02:48 GMT -5
Haha. DEM is very similar to LiDAR where you have assigned three coordinates for each point (a longitude, latitude, and altitude) and when you have a lot of points, it creates a 3D map. LiDAR is a little more complex as it may run several scans and make an educated guess as to what is ground, what is vegetation and what is a building, for example. As for the labor intensity of mapping out the points in Google Earth, it is actually not that hard, you just hold down the left mouse button and move your cursor around the course and it automatically lays down many points. The slower you move, the more point it puts down so if you moved around the green slower for example and faster around other areas that are less critical, I don't think it would take that long. Probably a few minutes per hole. I am pretty sure I have spent a lot more time trying to find the LiDAR data and the correct EPSG code than it would take me to map out a course. I am still trying to figure out which free tools I can use for classification and then exporting to LAS. I know I could do it with GlobalMapper as I did all of that for the Japan data that I converted, but that was with a free trial and I don't have access to that anymore.... Thanks Sirish. Yeah I know quite well what DEMs are, I was building courses for TW08 using them for several years. We did not have OSM though, but we could overlay Google Earth on top of the plot so that was OK. I did not know about the left button trick for GE, I will give it a try.
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Post by mctrees02 on Mar 17, 2021 6:21:39 GMT -5
sirish19 were you ever able to figure out how to get the elevation data from google earth into Chad's tool?
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Post by sirish19 on Mar 18, 2021 8:59:54 GMT -5
Hi @mctrees02, unfortunately, I wasn't really able to make any progress with this. I was able to convert and import the data, but the result was a lot flatter course than I thought it should be. I had a number of other projects that I was working on with better data so decided to prioritize those and didn't really follow up more with that. If you have any courses that you would like to give a shot at and have a KMZ file wanted to try to classify and convert, I would be happy to have a look and see if I can get it converted for you.
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Post by paddyjk19 on Mar 2, 2023 5:02:08 GMT -5
Just a little bump here;
I managed to get some data for a course I love in Ireland.
They only had 25cm photogeometric data. Basically a DSM in .ASC format or as a raw .XYZ text file. I’m sure there must be a way to classify this data for TGCTools.
I’ve followed a tutorial online but the data comes out skewed so obviously isn’t classifying properly.
Trying lots of things but not getting there yet!
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Post by combdaddy on Mar 13, 2023 12:20:27 GMT -5
Following this thread as well. I have a similar issue and would LOVE alternate formats to just Lidar.
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BrendanOR123
Amateur Golfer
Y'all are old compared to me!
Posts: 232
TGCT Name: Brendan O'Reilly
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Post by BrendanOR123 on Mar 13, 2023 13:19:23 GMT -5
Just a little bump here; I managed to get some data for a course I love in Ireland. They only had 25cm photogeometric data. Basically a DSM in .ASC format or as a raw .XYZ text file. I’m sure there must be a way to classify this data for TGCTools. I’ve followed a tutorial online but the data comes out skewed so obviously isn’t classifying properly. Trying lots of things but not getting there yet! As an Irish guy, I’m curious what course you got the data for?
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Post by paddyjk19 on Mar 16, 2023 19:13:12 GMT -5
Just a little bump here; I managed to get some data for a course I love in Ireland. They only had 25cm photogeometric data. Basically a DSM in .ASC format or as a raw .XYZ text file. I’m sure there must be a way to classify this data for TGCTools. I’ve followed a tutorial online but the data comes out skewed so obviously isn’t classifying properly. Trying lots of things but not getting there yet! As an Irish guy, I’m curious what course you got the data for? Was trying to get Waterville but it’s photogrammetry DSM so it can’t be classified properly. There’s some courses around Dublin that I’ve got to work so will get them out there in due course but ultimately I was keen to do Waterville, Ballybunion, Sligo and a few courses in Donegal but the data isn’t there yet. Got the topography for Royal Dublin, Portmarnock and County Louth though. I’m about 50% through RDGC so far
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