topic Re: EXTRACT BY ATTRIBUTE in ArcGIS Spatial Analyst Questions

EXTRACT BY ATTRIBUTE

FaeezaFortune — Mon, 27 Jun 2016 10:44:43 GMT

Hi there,

I want to extract open water surface's using Xu's (2006) MNDWI.

Essentially, for Landsat 8, I have done the TOA correction, this was followed by the MNDWI calculation- using the Ratser Math tool. Everything worked fine, until I got to the point where I needed to extract the cells containing water (i.e. cells with the value >0). To extract the water, I used the Extract by Attribute tool. The results turned out blank. I have no idea what I'm doing wrong.

Please help.

Thanks.

Faeeza

Re: EXTRACT BY ATTRIBUTE

DanPatterson_Retired — Mon, 27 Jun 2016 12:27:49 GMT

Is it a classified single band integer raster showing water and other stuff? and water is class 0?

Information from you table, histogram etc will be needed to see where you are going wrong.

Also... never rely on what you see on the screen, open the table... it should be an integer raster if done correctly, so you should have some results of the query there.

Re: EXTRACT BY ATTRIBUTE

FaeezaFortune — Tue, 28 Jun 2016 09:55:32 GMT

Hi, no it is not a integer, although it should be.

How does one change it to a single band/ classified integer raster data set?

The attribute table is disabled, to create one the data set needs to be a single band integer.

Could it be that I am possibly doing the TOA for Landsat 8 incorrectly?

Thanks,

Faeeza

P.S. Thanks for your response.

Re: EXTRACT BY ATTRIBUTE

DanPatterson_Retired — Mon, 04 Jul 2016 01:41:46 GMT

sorry for the delay... I suspect you haven't classified your image

What is image classification?—ArcGIS Help | ArcGIS for Desktop