topic Processing time/speed for Mosaic to New Raster in Data Management Questions

Processing time/speed for Mosaic to New Raster

Anonymous User — Tue, 12 Jan 2016 20:20:43 GMT

I have a question on speeding up “Mosaic to New Raster” or finding an alternative. After completing a suitability analysis we are trying to define movement corridors. We used a modified CircuitScape that left 4 folders, each containing 1080 raster tiles across our study area. We now need combine all 1080 rasters in each folder then combine these 4 combined rasters into a final raster which will be analyzed for paths.

I tried a python script that just wouldn’t work so I went on to Model Builder. It iterates through the grids in the folder, collects the values (raster names), then mosaics all to a new raster. It has been running for 5 days now and the results window indicates it is working. I’m hoping it will conclude in the next day or 2. But, we still have 3 more folders, each with 1080 rasters, that need to be mosaicked. So….is there a way to speed up Mosaic to New Raster or is there an alternative I could use to produce the final grid?

The cell size is 270 meters, 540 x 540 columns and rows, 1 band, 32 bit floating. Thanks

Re: Processing time/speed for Mosaic to New Raster

DanPatterson_Retired — Tue, 12 Jan 2016 20:33:52 GMT

analysed for paths...are all rasters likely to have a path or do you want to include all for the picture effect?

Re: Processing time/speed for Mosaic to New Raster

Anonymous User — Tue, 12 Jan 2016 20:39:48 GMT

No, not all rasters will have a path. But until we can view them we

won't know which will and which won't. We also will need to find the

best "less than desirable" habitat for paths from one high suitable

areas to another suitable area across distances up to 200 kilometers.

These areas will have a weak current value but will still qualify as a

path. We do not have a cut-off value for what constitutes a path.

Thank you

Re: Processing time/speed for Mosaic to New Raster

DanPatterson_Retired — Tue, 12 Jan 2016 20:46:42 GMT

I am not sure what you mean by "view them". In their entirety I presume. I can only suggest pruning out candidates or tiling. If you intend to use the result view for further processing, you will continue to have problems unless you can scale the area down by selection, extent, cell size or similar reductions.

Re: Processing time/speed for Mosaic to New Raster

Anonymous User — Tue, 12 Jan 2016 20:56:36 GMT

Yes, by "view them" I meant as an entirety. I think we may have to end

up tiling.

Re: Processing time/speed for Mosaic to New Raster

DanPatterson_Retired — Tue, 12 Jan 2016 21:11:25 GMT

maybe you ruled this out? What is a mosaic dataset?—Help | ArcGIS for Desktop

Re: Processing time/speed for Mosaic to New Raster

Anonymous User — Tue, 12 Jan 2016 21:15:12 GMT

I haven't ruled it out and began investigating it yesterday but I do not

know enough about it to make an informed choice.

Re: Processing time/speed for Mosaic to New Raster

DanPatterson_Retired — Tue, 12 Jan 2016 21:20:06 GMT

I think it is your best option when compared to trying to make one composite. The help topics should give you an idea and there has been enough traffic on the topic that there is lots of documentation

Re: Processing time/speed for Mosaic to New Raster

DanPatterson_Retired — Tue, 12 Jan 2016 21:24:55 GMT

Re: Processing time/speed for Mosaic to New Raster

Anonymous User — Tue, 12 Jan 2016 21:26:00 GMT

Thanks. I will read further on it and try some test areas.

Re: Processing time/speed for Mosaic to New Raster

Anonymous User — Tue, 12 Jan 2016 21:28:24 GMT

I appreciate this very much!

Re: Processing time/speed for Mosaic to New Raster

MikeCusi — Tue, 12 Jan 2016 22:42:58 GMT

I was in a similar situation a while back when mosaic datasets were but a dream. As Dan Patterson suggested, your best bet is using it as all the raster and spatial analyst (map algebra, etc) geoprocessing tools (maybe some others) support it. Besides, you'd also probably want to keep your original 1080 tiles and what better way to keep them than in its native format plus you need not use up additional space for your mosaic.

A few things I've learned.... large jobs like this run faster on local hard drives than from the network particlularly if your working files are in another physical hard drive other than your system files (where your temp files/virtual memory files are written). this is true even for mosaic datasets..... if you set priority to high (right click on the ArcMap.exe*32 in the Processes tab of windows task manager) or Realtime (if you are more daring) it will complete faster.... there are of course, some risks.... If you insist on creating a single mosaic, I also found that mosaicking small batches of adjacent tiles as an intermediate mosaic then eventually mosaicking the intermediates worked out faster (albeit with a bit more human intervention) than mosaicking all of the tiles at one time...

Re: Processing time/speed for Mosaic to New Raster

Anonymous User — Wed, 13 Jan 2016 16:23:31 GMT

Thank you. I have some learning to do with Mosaic Datasets but that seems to be the way to go. The alternative is to invest time in recognizing the file naming structure and then set up small mosaics.

Re: Processing time/speed for Mosaic to New Raster

MikeCusi — Wed, 13 Jan 2016 22:29:41 GMT

If you create a mosaic dataset, the resulting attribute table of the footprints can help you figure out the naming convention used by the software you used to generate the rasters. You can use it to select which rasters can make up your intermediate mosaics.