topic Re: Merging raster files in ArcGIS Spatial Analyst Questions

Merging raster files

BritainieLam — Thu, 22 Dec 2011 22:00:06 GMT

Hi,
I am working on a project that needs to merge raster files. I know there is the mosaic option but I also know there is a simpler way to do it in spatial analyst. Does anyone know the tool?

Re: Merging raster files

DanPatterson_Retired — Fri, 23 Dec 2011 13:38:41 GMT

Mosaic to new raster in data management tools is an option
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//001700000098000000

Re: Merging raster files

GayathriAlallasundaram — Tue, 27 Dec 2011 14:02:50 GMT

Hi,

In 9.3.1, the Raster calulator in the Spatial Analyst Toolbar could be used to merge rasters. The syntax for merge in raster calculator is: merge[[Raster1],[Raster2],...]. Click Evaluate and a temporary file is automatically added into ArcMap. Right click on the temporary file and select Data > Make Permanent.

In 10.0, the merge function is not available in the raster Calculator. However, the Mosaic tool and Mosaic To New raster tool (Data Management Tools > raster > raster dataset) can be used to merge rasters (you can also use these tools to merge rasters in 9.3.1).

Regards,
Gayu

Re: Merging raster files

BritainieLam — Tue, 27 Dec 2011 16:04:57 GMT

Thank you gayu and Dan_patterson for the help. I really appreciate it.

Re: Merging raster files

BritainieLam — Tue, 27 Dec 2011 16:26:29 GMT

Hi, So I followed the steps that you guys gave me (mosaic -> raster then I added the raster data set to the tool and output it to a folder. When I ran the tool I came up with a big black spot. Do you know why this would have happened?

Re: Merging raster files

GayathriAlallasundaram — Tue, 27 Dec 2011 17:58:56 GMT

Run statistics on the output. You can do this either by right clicking the output raster in ArcCatalog and selecting Calculate Statistics or using the geoprocessing tool (ArcToolbox > Data Management tools > Raster > Raster Properties> Calculate Statistics).

Regards,
Gayu

Re: Merging raster files

BritainieLam — Tue, 27 Dec 2011 22:07:04 GMT

Hey gayu,
by any chance would you know how to export each grid feature into their own shapefile? I know we can use the query tool but that seems complicated. Do you know any simple way of doing this?

Re: Merging raster files

GayathriAlallasundaram — Wed, 28 Dec 2011 14:54:40 GMT

Hey gayu,
by any chance would you know how to export each grid feature into their own shapefile? I know we can use the query tool but that seems complicated. Do you know any simple way of doing this?

Hi Britainie,
Could you please ellaborate on what you are tryin to do? I am guessing you are trying to export each grid feature from your polygon feature into a new shapefile. And also are you having version 9.3.1 or 10?

Regards,
Gayu