High Resolution Imagery from National Map

These screen captures are not current.  If you want to get this data, you will have to figure out what to do with slightly different windows.

National Map imagery available for Annapolis.  Be careful about the size of the region you request since these files can rapidly grow to huge sizes.
  • 0.15 m data has about 10 times more pixels than 0.5 m, and about 40 times more than 1.0 meter data
  • The four band NAIP allows selection of either true color or false color IR.  The "A" in NAIP stands for agriculture, so it might also be leaf on, making things hard to see on the ground.  Non agricultural users like geologists or hikers often prefer leaf off imagery to see through the trees.
  • You may have to decide if you lots of detail for a small area, or a larger area with less detail.
  • The data is in prestaged tiles, mostly in JPG2000 format.  You will need GDAL to open the imagery in MICRODEM.  It will convert the JP2 to a Geotiff in c:\mapdata\temp which will be purged when you close MICRODEM.

JPG2000 (JP2)  is lossy compression.

Some of these data sets are in a WGS_1984_Web_Mercator_Auxiliary_Sphere projection.  You will find this when you try to open the JP2, and you are asked about the projection, and it shows up in the wrong location.  You can verify this by looking in the Geotiff File Metadata for the Geotiff created by GDAL, which will be in c:\mapdata\temp.  For this data you must warp the image to usable UTM coordinates, on the Resample menu.  You also need to get the Geotiffs out of c:\mapdata\temp because that directory will be purged when you close MICRODEM.

If you need to merge tiles, get ready for the command line using GDAL.

   
The current version of the National Map should have a download link in the browser.  The older version sent an email which arrived almost immediately.

NAIP (1.46 m pixels).  Data available in March 2014.

0.5 m imagery.  Data available in March 2014.

0.15 m imagery.  Data available in March 2014.
This region returns a 28 MB image at 0.5 foot resolution, shown here in very reduced resolution.  Picking a large region can rapidly lead to data overload.  This was  data available in fall 2012.
Full resolution of the 6" imagery, clearly showing each gravestone.  The March timing for the imagery acquisition means that the trees are bare and do not mask much of the ground. This was the data available in fall 2012.


Last revision 2/24/2017