Pima County Geographic Information Systems
GIS Library - Imagery
Viewing Orthophoto Imagery and Information
Choosing a MapGuide map for viewing orthophotos
All Regional Orthophoto Project imagery, elevation data, and more can be viewed using
our Pima County MapGuide Maps with either the Main MapGuide Map or the Orthophoto Map.
Generally the Main MapGuide Map is best, but the orthophoto imagery is off by default.
Some prefer the more limited Orthophoto map where imagery is on by default.
- Choose the Main MapGuide Map to see virtually all data layers available on MapGuide in addition
to orthophotos. The orthophotos are off by default.
Other data layers showing areas (polygons) are often solid colors and will block viewing of the orthophotos.
- Choose the Orthophoto Map to get a map with the orthophotos on by default and just a few point and vector layers for reference.
Other data layers showing areas (polygons) are hatched so you can see the photos through the hatched layers
The orthophotos are implemented as a number of layers for different scales (zoom levels), but you only see one
orthophoto layer in the legend at a time in the orthophoto group.
It's generally best to turn the orthophotos on or off by checking the layer group box rather than
the layer for the current scale being displayed.
Turning the layer group on or off effectively turns all the layers for different scales
on and off at the same time.
Finding orthophoto information in the MapGuide map legend
-
Orthophoto imagery is towards the bottom of the MapGuide layer legend.
The orthophoto imagery layers are sorted by date with the most recent first.
- Most recent high resolution imagery: 2012 Spring Pictometry Color Orthophoto Imagery shows multispectral (color) imagery from 2012.
This layer includes most of metropolitan eastern Pima County but is not as extensive as PAG orthophoto projects.
The resolution is 4 inches across the entire project area.
Horizontal accuracy is not specified.
- All PAG Color Orthophoto Imagery includes the imagery from the
2002,
2005,
2008, and
2011
projects with the latest imagery overlaying portions of older imagery.
The 2005, 2008 and 2011 project areas are generally smaller than the 2002 area, although they also include some small areas outside the 2002 project area.
By using the All PAG Color Orthophoto Imagery group, you always see the latest available high-resolution color imagery.
The highest resolution for All PAG Color Orthophoto Imagery is 1 foot, even though the 2005, 2008, and 2011 projects include
some areas of 6 inch, 4 inch, and 6 inch resolution respectively.
To see the higher resolutions, zoom in close and use the
2011/04 PAG Color Orthophoto Imagery,
2008/05 PAG Color Orthophoto Imagery, or
2005/05 PAG Color Orthophoto Imagery
where 2011 image uses 6 inch resolution by default
and for 2008 and 2005 you can turn on the
higher resolution image as separate layers in the legend.
- 2011/04 PAG Color Orthophoto Imagery shows multispectral (color) imagery from 2011.
This layer includes most of metropolitan eastern Pima County and some areas beyond the county border in Pinal and Cochise counties.
The older 2002 PAG Color Orthophoto Imagery layer is more extensive, covering all of eastern Pima County.
The resolution is 6 inches across the entire project area.
- 2010 Summer USDA/FSA NAIP Natural Color Imagery
covers all of Pima County. It has a lower resolution than the PAG and Pictometry orthophotos.
- 2010 Spring Pictometry Color Orthophoto Imagery shows multispectral (color) imagery from 2010.
This layer includes most of metropolitan eastern Pima County but is not as extensive as PAG orthophoto projects.
The resolution is 4 inches across the entire project area.
Horizontal accuracy is not specified.
- 2008 Pantano Wash Color Imagery straddles an area along the Pantano Wash from near the intersection of RIVER RD and CRAYCROFT RD
southeast to approximately 1.5 miles beyond COLOSSAL CAVE RD.
- 2008/05 Pictometry Color Orthophoto Imagery shows multispectral (color) imagery from 2008.
This layer includes most of metropolitan eastern Pima County but is not as extensive as PAG orthophoto projects.
The resolution is 4 inches across the entire project area.
Horizontal accuracy is not specified.
- 2008/04 PAG Color Orthophoto Imagery shows multispectral (color) imagery from 2008.
This layer includes most of metropolitan eastern Pima County and some areas beyond the county border in Pinal and Cochise counties.
The older 2002 PAG Color Orthophoto Imagery layer is more extensive, covering all of eastern Pima County.
Generally, the highest resolution is 4 inches in central and more populated areas and 1 foot for the covered outlying areas.
Our MapGuide maps may not display all available resolutions.
For horizontal accuracy,
95% of all planimetric features that are well defined on the photograph are accurate to
at least +/-3.0 feet of their true coordinate position.
None of the features are displaced more than +/-6.0 feet from their true coordinate position.
- 2007/06 USDA/FSA NAIP Natural Color Imagery
- 2007 Rillito River Color Imagery straddles an area along the Rillito River from I-10 southeast to CRAYCROFT RD.
- 2006/03 USGS (MDA) Natural Color Imagery
- 2005/05 PAG Color Orthophoto Imagery shows multispectral (color) imagery from 2005.
This layer includes most of eastern Pima County and some areas beyond the county border in Pinal and Cochise counties.
The older 2002 PAG Color Orthophoto Imagery layer is more extensive, covering all of eastern Pima County.
Generally, the highest resolution is 6 inches in central areas and 1 foot for the covered outlying areas.
Two PLSS sections near the University of Arizona include 3 inch resolution.
Our MapGuide maps may not display all available resolutions.
For horizontal accuracy,
95% of all planimetric features that are well defined on the photograph are accurate to
at least +/-3.0 feet of their true coordinate position.
None of the features are displaced more than +/-6.0 feet from their true coordinate position.
- 2004 Hayhook Ranch Imagery is from a limited area project along State Highway 86 west of Robles Junction.
- 2003 Ajo Orthophoto Imagery is from an 8/12/2003 limited area project in Ajo.
- 2003/09 Mt. Lemmon Color IR Imagery
- 2003 Rio Medio Grayscale Imagery straddles an area along I-10 from 22ND ST to north of PRINCE RD.
- 2002 Rillito River Color Imagery straddles an area along the Rillito River from INA RD southeast to CRAYCROFT RD.
- All PAG Grayscale Orthophoto Imagery includes the imagery from the
1998,
2000 and
2002 projects with the latest imagery overlaying portions of older imagery.
The 2002 and 2000 project areas are generally smaller than the 1998 area, although they also include some areas outside other project areas.
By using this group, you always see the latest available grayscale imagery.
The highest resolution for All PAG Grayscale Orthophoto Imagery is 1 foot, even though the 2000 and 2002 projects include
6 inch resolution.
To see 6 inch resolution, see 2000 PAG Grayscale Orthophoto Imagery and 2002 PAG Grayscale Orthophoto Imagery.
For horizontal accuracy, 95% of all planimetric features are accurate to within 2 feet of their true coordinate position.
The remaining 5% are displaced by no more than 4 feet.
- 2002 PAG Grayscale Orthophoto Imagery shows grayscale imagery only from 2002.
The is the only MapGuide layer that can show the full 6 inch resolution for 2002 grayscale imagery.
- 2002 PAG Color Orthophoto Imagery shows multispectral (color) imagery only from 2002.
This layer includes all of eastern Pima County and some areas beyond the county border in Pinal County.
The 2002 PAG Color Orthophoto Imagery includes information for the entire area as it
includes all areas that were in prior projects.
The highest resolution is 1 foot although it doesn't appear quite as sharp as the 1 foot grayscale imagery.
For horizontal accuracy, 95% of all planimetric features are accurate to within 4 feet of their true coordinate position.
The remaining 5% are displaced by no more than 8 feet.
- 2001 University of Arizona Color Imagery includes the university and surrounding area from GRANT RD to BROADWAY BL.
- 2000 PAG Grayscale Orthophoto Imagery shows grayscale imagery only from 2000 and is useful for historical or comparison studies.
The is the only MapGuide layer that can show the full 6 inch resolution for 2000 grayscale imagery.
- 1998/04 PAG Grayscale Orthophoto Imagery shows grayscale imagery only form 1998 and is useful for historical or comparison studies.
The highest resolution is 1 foot.
- 1996-1997 USGS Color Infrared Imagery
- Topography information is towards the top of the MapGuide layer legend in a group called Topography - PAG Orthophotos which contains layers
with and without labels for each year's elevation projects.
Note that for any given imagery year, the elevation data may not be as extensive as years after 1998 used some elevation data from prior project years.
- Project coverage information is in a group called Orthophoto Project Areas, somewhat in the middle of the MapGuide legend layers.
These layers show the project coverage for different image types (color, black and white) as well as project coverage for elevation model types (DEM, DTM, LIDAR).
Also see Status Maps showing coverage for all PAG orthophoto projects.
Image resolutions
The Pima County MapGuide server stores several pre-sampled image resolutions for each orthophoto layer.
For instance, for the PAG 1998 grayscale orthophotos,the server stores
seven pre-sampled panchromatic grayscale image resolutions from 64 foot pixels all the way down to 1 foot pixels.
The server selects the data for your current view from image files with the most appropriate resolution
as follows:
| Scale | Image Resolution |
|---|
| 0-200 | 6 inch (where available) |
| 201-3,000 | 1 foot |
| 3,001-5,000 | 2 foot |
| 5,001-12,000 | 4 foot |
| 12,001-30,000 | 8 foot |
| 30,001-50,000 | 16 foot |
| 50,001-100,000 | 32 foot |
| 100,001-1,500,000 | 64 foot |
The MapGuide server
re-samples the image on-the-fly, resulting in the smallest possible data transfers at all viewing scales.
If the change in scale is small, the image may be re-displayed at the new scale without being re-sampled
on the server.
You can force a re-sample at the current scale by
right-clicking on the imagery layer name in the MapGuide legend and select "Rebuild".
For more on getting the best possible image to view,
see Optimizing Orthophotos, Imagery and Map Details.
The MapGuide server manages selecting the displayed data from a large number of photo data tiles, stitches it together when necessary, and presents it to the user, making it appear as one giant seamless image.
The intensive processing is done on the server, not your PC, and generally takes a few seconds for each
new view.
Capturing the Data in Your MapGuide View
See Capturing Your MapGuide View
to learn how to save the viewed map data from the screen to a file.