topic Re: Raster Projecting Incorrectly in Coordinate Reference Systems Questions

Raster Projecting Incorrectly

GlendaWyatt — Thu, 17 Aug 2017 22:03:08 GMT

My map is in NAD1983 UTM Zone 9N. I am importing a raster that (when opened on it's own) looks fine and is in WGS84. When I add the raster to my map, it projects incorrectly. Any suggestions on how to start resolving this would be greatly appreciated. The raster was exported from Q.

Re: Raster Projecting Incorrectly

DanPatterson_Retired — Thu, 17 Aug 2017 23:23:52 GMT

check the raster properties, and report the extent so that the extent can be compared with what the projection is supposed to be.

Add this layer to a new data frame... Do NOT add a base map... check the properties of the data frame

Continue to add other layers.

If the extent and projection information in step 1 aren't good, then there are other things that need to be done

Re: Raster Projecting Incorrectly

MelitaKennedy — Fri, 18 Aug 2017 00:06:38 GMT

The raster itself has a longitude range of 0 to 360. Is that what the raster's extent shows?

Melita

Re: Raster Projecting Incorrectly

AbdullahAnter — Fri, 18 Aug 2017 08:46:15 GMT

Project this raster to NAD1983 UTM Zone 9N, before you add it in your map

using Project Raster—Help | ArcGIS Desktop .

Re: Raster Projecting Incorrectly

GlendaWyatt — Fri, 18 Aug 2017 18:25:46 GMT

I brought it into a new blank map. The extents are:

Left: -0.5

Right: 255.5

Top: 0.5

Bottom: -191.5

Re: Raster Projecting Incorrectly

GlendaWyatt — Fri, 18 Aug 2017 18:26:41 GMT

No. When I query the extents, they are:

The extents are:

Left: -0.5

Right: 255.5

Top: 0.5

Bottom: -191.5

Re: Raster Projecting Incorrectly

GlendaWyatt — Fri, 18 Aug 2017 18:33:48 GMT

I tried that and I get a warning

'inconsistent extent' - one or more added layers has an extent that is not consistent with the associated reference information. Re-projecting the data in such a layer may lead to unexpected behavior.

Re: Raster Projecting Incorrectly

DanPatterson_Retired — Fri, 18 Aug 2017 19:54:47 GMT

Left: -0.5

Right: 255.5

Top: 0.5

Bottom: -191.5

This is just an image extent, 256 cells wide, 190 cells high, it is effectively a picture. Projecting it isn't going to do anything, unless you can give it a defined coordinate system and to make it useful, you would have to know the cell size. Perhaps you have other files drifting around in the same location as that one... or do you have any metadata? or can you find the original source to fill in the gaps?

Re: Raster Projecting Incorrectly

AbdullahAnter — Fri, 18 Aug 2017 20:00:57 GMT

Read the following link: it has a solution:

Error: One or more of the added layers has an extent not consistent with spatial reference

Solution or Workaround
The operation that yields this warning has been modified in ArcGIS Version 8.1.2.

To determine if this problem applies to the coordinate range and angular units of your data, do the following:

Start ArcCatalog and navigate to the dataset that returns the message.
Click the Metadata tab on the right-hand window.
Click the Spatial tab.

The 'Bounding Coordinates' section lists the extents of the data in decimal degrees. If these extents exceed the range of -180 to 180 (longitude), or -90 to 90 (latitude), the extent not consistent with spatial reference message will erroneously appear when adding this data.
If possible, correct the defined coordinate system for your data (you may need to refer to current metadata for more information).

Re: Raster Projecting Incorrectly

GlendaWyatt — Sat, 19 Aug 2017 22:53:03 GMT

I asked this question on another forum and this was a comment that seemed to make sense (with how the data is coming out of Q):
"It's not georeferenced yet. That is, although it has a coordinate system definition of WGS84, the raster extents are in decimal degrees but are in the raw cell numbers. If you check the raster's cell count, you should see 256x192"

Re: Raster Projecting Incorrectly

DanPatterson_Retired — Sun, 20 Aug 2017 01:39:11 GMT

So to 'fix' this, you need to know the real world extent of your input file in longitude/latitude coordinates.

The coordinate definition of WGS84 is wrong since the raw row/column format has to be translated

row/col long/lat

0,0 -180, 90

0, 192 180, 90

128, 96 0, 0 Greenwich, Equator

192, 0 -180, -90

192, 256 180, -90

so you have a cell size in the long/lat (ie X,Y) directions

I assume Q can't finish the provision of real world coordinates.

Re: Raster Projecting Incorrectly

GlendaWyatt — Sun, 20 Aug 2017 20:52:22 GMT

Luckily, my input is the entire earth surface with the western edge being at Greenwich. Do you know if there is a way to define this in ArcGIS without having to register points?

Re: Raster Projecting Incorrectly

GlendaWyatt — Sun, 20 Aug 2017 20:55:59 GMT

I'm also going to try to georeference in Q and then try Arc when I am back in the office tomorrow. Thanks again for your help.

Re: Raster Projecting Incorrectly

MelitaKennedy — Mon, 21 Aug 2017 18:22:23 GMT

That was actually my comment and should have had a "not" in there: ...the raster extents are not in decimal degrees...

Re: Raster Projecting Incorrectly

Naby79 — Thu, 24 Jun 2021 19:51:13 GMT

I have the same issue. I know the real world extent of the file, how to update it?