Vector Contour Mosaic Dataset

[forestknutsen1]

I am trying to run the contour tool on a mosaic dataset with a 10 meter contour interval. But it keeps failing or hanging. The elevation data is all from the NED. It is mostly IFSAR with some 2 second arc stuff to fill it out. I have calculated stats on each image and on the mosaic. I have tried it with the contours "smoothing only" raster function on and off. Suggestions?

[forestknutsen1]

[SteveLynch]

I would suggest that you try the following;

1) increase the contour interval (just for testing) to say 100 (or a value = half of the range of your data)

2) if this succeeds then gradually decrease the interval

3) if #1 fails, the use CopyRaster and save the output to a .tif or fgdb raster. How many columns/rows does the raster have?

also, what version of ArcMap?, have you tried ArcGIS Pro?

Regards

-Steve

[forestknutsen1]

Thanks for the feedback Steve.

1) This worked at 100 meters I will try cutting them down more

2) Working on it

3) I did not do this. but the mosaic has 116,380 columns and 21988 rows.

I am using Arc 10.3.1. I could try Pro. I have access to Pro 1.4.1 and lower.

[SteveLynch · Accepted solution]

Forest

I believe that you are running into memory issues when using the small contour interval.

You could SplitRaster<http://pro.arcgis.com/en/pro-app/tool-reference/data-management/split-raster.htm> your raster into tiles (and use a one cell overlap) and contour each tile. Because of the one cell overlap the contours will line up exactly as contours are drawn to circa half a cell from the edge.

-Steve

[forestknutsen1]

Okay, I will give that a go. I only need the small contour interval for the first 500 meters of elevation because it is more or less flat. Last night I ran the Contour List tool with just 9 values and it did not complete by this morning. I did dramatically increase my virtual memory days ago but still getting the error at times so still not enough...

[CodyBenkelman]

Forest

I've been watching this thread but don't really have time to engage.  I'm just curious to confirm - at top you mention using the contour raster function.   Is that attached to this MD, and have you defined "smoothing only" (with desired parameters) on the elevation MD before passing that into the GP tool for creating contours? 

other questions - you *do* need vector contours?  the raster contour function is not adequate for your needs?  (If you have a flat area, the dynamic raster contours can show narrower contour interval there, and a wider contour interval in areas with more terrain)

I'll be honest, I haven't tried running the contour GP tool with an elevation MD with contour function (smoothing only) applied.  You might try removing the contour function first.   If that works, do you feel the smoothing is critical to this output?   

and per Steve's suggestion that memory may be an issue, can you try running a small area of interest?   I'd like to avoid telling you "you have to create tiled raster outputs first" - you SHOULD be able to just use the MD directly.

Cody B

[forestknutsen1]

Hi Cody,

I did apply the raster function to the MD with the smoothing the only option. I did this because it was indicated in the user documentation that was packaged with the tool download.

"Vector Contours
If vector format smoothed contours are required, they can be created in two steps. First, use the contour ‘Smoothing only’ mode (see below) and either export the resulting DEM as a raster saved to disk, or save a raster layer that includes the ‘Smoothing only’ mode. Then, use the Contour function available in ArcGIS Spatial Analyst to generate the vector contours, using the smoothed DEM or raster layer as input."

I did also try it with the smoothing option off.

Also, I looked at the raster contour function. It is very nice. I like how it adjusts the contour interval on the fly. But I have two problems with it.

1) No labels. I see the suggestion is to create spot heights... 

2) Not sure how I am going to host this - I am waiting to hear if we have access to ArcGIS sever with image extension for the project.

Forest 

[forestknutsen1]

This worked great. Thanks, Steve.