I have bathymetry data (1 huge data) = SRTM/DEM/FGDBRaster (0,9818m resolution pixel, floating, 32 bit, 45 GB size)

and an alternative data (split into small pieces data) = same data but with 1m res pixels.

My task is convert the data into point with 10m distance between point and getting depth value (positive and negative) from my DEM data. I will use that point and label it with depth value (negative and positive value), and put that point on top of my bathymetry map

My method is:

  1. Using "Resample" tool to reduce the raster resolution first (nearest neighborhood, 9,818m width/height cell factor)

  2. Then convert into point using "Raster to Point" tool

My questions are:

  1. Is there any other method with better/accurate way than I did? (I use nearest neighborhood cause the value didnt change and I think that is the best resample than others)

  2. When I resample my source data (0,9818m) should I use 9,818m cell factor or 10m cell factor?

  3. What if I convert the DEM first into point, then reduce the point from 1m distance to 10/9,818 m distance (I still don't what tool to reduce the point that can mantain the accuracy between point and my DEM depth value), is that less accurate method?

  • 1
    Please take the Tour, which emphasizes the importance of asking one question per Question, then Edit the Question to ask one question. Please avoid opinion-based issues where you are effectively soliciting a discussion discussion, because we use a Question/Answer model. – Vince Oct 15 '18 at 12:28

If you have access to ArcGIS with 3D analyst and an advanced license you could generate a fishnet over your area of interest with a 10m height and widths. There is an option in Create Fishnet called Create Label Points. The label points will be the cell centers of your fishnet. Then use 3D Analyst-Functional Surface - Add Surface Information and populate your label points with surface model values.

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  • maybe it can works, but the method can be used in "add surface info" is billinear only, cant choose others except for TIN input, so which one will provide more accurate result? "fishnet and add surface" or "resample raster first using neighborhood and raster to point" ? – Budi Badu Oct 15 '18 at 22:34
  • and if i use fishnet, do you have any idea how to clip the point that created by fishnet considering the raster not a square shape, and also there is 0 value depth inside raster that i want to keep, i just want to delete point outside my raster boundary, is there any solution for that? – Budi Badu Oct 15 '18 at 22:39
  • If you have access to Spatial Analyst you can also use the "Extract Values to Points" Tool. If your raster is irregular in size you can use the "Select by Attributes" function to select all values of "No Data" which is normally -9999 in the attribute table. You can delete out anything that is selected. The above method should work for what you are looking for. – Keagan Allan Oct 16 '18 at 0:34

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