MD: Control Scale Level of res change

[forestknutsen1]

I have a test MD with 6 inch, 12 inch, 1 meter, and 1.4 meter resolution imagery. It does not make the change from the 1 meter to the 6 inch or 12 inch until the scale is 1:1000. I would like it to change around 1:3000 or so. How can I do this?

[JimCousins]

Under the properties, general tab, you can set the minimum and maximum scale for display.

[forestknutsen1]

In the mosaic dataset properties?

[JimCousins]

Forest, I work with stand alone rasters, and do not know the ins and outs of mosaic datasets. The scale properties for display for me are available in the table of contents, properties for each individual raster dataset. Apologies to leave you without a targeted solution on this, but I was unaware it was a raster mosaic.

Regards,

Jim

[forestknutsen1]

Ah, yes. Thanks for the input Jim. I should have been more explicit in my first post.

[CodyBenkelman · Accepted solution]

Forest

I'll write a quick answer and then follow with something more verbose.

The short answer to controlling visibility of different rasters in a mosaic dataset are the MinPS and MaxPS values in the attribute table.  "Calculate Item Visibility" will set the values for you, but may not do exactly what you want depending on your different resolutions.  If you're comfortable with CalculateValues, you can set those values manually.  

PS means PixelSize, and will usually be in units of meters (may be feet if your MD coordinate system is state plane).  If you'd rather work with photo scale, you can apply an equation to convert but I'll skip that unless you need it.  

Visibility of any given raster will be ON when the resolution of the current view is between the Min and Max values.  (Don't get confused by LowPS and HighPS which tell you the raw pixel sizes in your rasters.  If these two values are not the same value, then your raster has pyramids)

If you want to be able to zoom in beyond full resolution, make sure your highest resolution layer has a MinPS=0

You haven't noted if you're using ArcMap or ArcGIS Pro...

See my next post for more background.

Cody B

[CodyBenkelman]

Forest

Adding more to my response above:

1. there's another parameter that controls "Which image is on top?" if you have multiple rasters in the same location and both within the active Min/MaxPS visibility range: the Mosaic Method.  I'd typically recommend Mosaic Method = By Attribute, and then direct it at the LowPS value in the attribute table. 
   1. Result: Ignoring the visibility range of Min/MaxPS, this will always display the highest res (= lowest numeric value) on top.  Then when Min/MaxPS is applied, if you're zoomed out to 1:4000, the 6inch and 12inch should be off.
   2. Note: Presuming you have datasets that overlap in most areas but perhaps not everywhere, you may not want your lower res data to disappear based only on current display scale. In this case, set MinPS = 0 for all rasters (so the screen should not go blank when you zoom in, if a raster exists there) but be sure the Mosaic Method is set to display the highest resolution, and then the MaxPS values determine when the higher res layers disappear to reveal the lower res
   3. tangential side note: if you ever use this method to order rasters by date, you will likely have to select the checkbox for Reverse Order, or your date field will result in the OLDEST image on top since the Mosaic Method orders rasters by the lowest numeric value, and the date field increases with time. 
2. I assume you have learned about reduced resolution views called either Pyramids (associated with the source rasters) or Overviews (similar, but applied to the entire mosaic, not individual rasters).  If these aren't set up correctly you can get unexpected behavior of what is visible, but in your case (6", 12", 1m, 1.4m) you shouldn't run into confusion about the Overviews. Short version:  if you've built them but visibility wasn't working properly beforehand, I'd delete the overviews, get visibility working from 0 to 3 meters (scale about 1:12,000) and then build overviews starting at ~4 m (3x your lowest resolution) for when you're zoomed further out.
3. Presuming you need this to be a robust, maintainable system and perhaps more data is coming in the future, I'd strongly encourage you invest time looking at http://esriurl.com/ImageryWorkflows:
   1. General advice for Mosaic Dataset configuration
      1. (I've seen your other posts this week about color correction and seamlines; sorry I haven't had time to reply to those)
   2. example scripts to enable configuration of an automated system. 
   3. Specifically, look for Preprocessed Orthos which is directly applicable to your case ( Introduction—Managing Preprocessed Orthophotos | ArcGIS )

I think those are the key points I wanted to offer.  If I think of more, I may post further.  Let us know if you have further questions

Cody

[forestknutsen1]

Thanks Cody! You always give great feedback. I will experiment with the order problem soon. 

I am doing the work on Arc 10.6.

FYI: I think I have the seamlines sorted out - they are looking good overall. I deleted the post. I may still need some input on the color problem.

[forestknutsen1]

Thanks Cody and Peter for all the help on this.

[PeterBecker]

Just to extend on what Cody has put.

The primary way that the display range is defined is using the MinPS and MaxPS values.

These are range of screen pixel size at which the images should be displayed.

Pixelsize is typically used it directly relates to the resolution of the imagery.

The conversion form PS (in meters) to Scale. Scale = Pixel Size * 96/0.0254       Pixel Size (in meters) = Scale * 0.0254/96

Assuming that the four datasets exactly overlap you could set the following

Datasets				From	To
	MinPS	MaxPS		Scale 1:	Scale 1:
6"	0	0.1524		0	576
12"	15.24	0.3068		576	1160
1m	30.68	1		1160	3780
1.4m	1.4	14		3780	52913

This would result in the datasets only being displayed between the defined scale ranges such that you are always seeing the best resolution for the map scale.

If you wanted 12" to be displayed till 1:3000 then you could change to 

Datasets				From	To
	MinPS	MaxPS		Scale 1:	Scale 1:
6"	0	0.1524		0	576
12"	0.1524	0.79375		576	3000
1m	0.79375	1		3000	3780
1.4m	1	14		3780	52913

You could change any of the MinPS and MaxPS value so that they overlap. Eg 6" only partially covers the 12" and you might set the MinPS of the 12" to 0 so that in those areas the 12" is also considered. In these areas with both 6 and 12" the question is now which should be displayed. The system will actually try and attempt to determine the most appropriate first (ie closest to natural scale), but these values can be overwritten by the ZOrder filed or mosaic method and appropriate attribute.

Note that Calculate Cell Size Ranges attempts to determine the appropriate MinPS and MaxPS values based on the overlapping imagery and their respective pixel sizes and availability of pyramids, but sometimes it is better to define the value explicitly. The rules are very useful cases where you have datasets that should always form a background at lower priority or you want to define explicit rules.

[Note. This is an edited version. In the original version of this reply, I had put LoPS/HiPS instead of MinPS/MaxPS in some places. I also clarified that PS values in these examples are in meters)