Neither the World Imagery basemap in ArcMap nor the service at ArcGIS Online provide high resolution (0.3m) images anymore.
Has anybody been able to access the 0.3m resolution imagery recently?
Here is the longer question statement:
According to the metadata here, Esri High Resolution Imagery
should have 0.3m resolution imagery in the continental United States. However, neither that or the new alternative, World Imagery (Clarity) look like 0.3m imagery. Below are example images from Massachusetts, USA, near coordinates (-70.655505, 41.515357). The first two are from World imagery, and the other are from Clarity. Note the scale bar in the bottom left corner. The resolution does not seem to be 0.3m.
Here is a comparison of a 1m resolution imagery from another source (top) to the World Imagery for the same area (bottom). In the top image one can clearly see the raster cells of size of 1m. Not the same for the Esri image. It is blurred and does not seem to be 0.3m resolution in contrast to what the image info states.
Can anybody successfully see a 0.3m resolution imagery as a basemap or through any of the services?
Two ways to reproduce this issue:
- You can follow the Esri High Resolution Imagery link to reproduce this issue online.
- Or in ArcMap go to menu Add Basemaps -> Imagery.
Here is a list of posts pointing to the same problem:
Best Answer
"0.3m resolution" means that one pixel in a raster map is 0.3m on the ground.
It usually means that a particular raster map, from its output/native resolution, can be "zoomed in" (interpolated) up to the specified resolution without loss of visual coherence. For instance, a collection of source images taken at approx 1m resolution were used to produce a raster map at 1.2m resolution, and the users can "zoom in" at up to 0.6m resolution. (Not exact numbers but arbitrarily chosen to illustrate a point.)
To ascertain the resolution quality of a raster map, one must first look at it at its production resolution, where one one pixel in the raster map is shown using one pixel on the LCD screen. For a standalone raster map, this is straightforward. For a raster map service, you need to identify the layer that gives the highest native resolution. The screen shot below shows the given raster map service, at the given AOI, at 100% native resolution.
A quick hand-computation shows that the production pixel resolution (for this extent) is approx 0.8m ~ 1m resolution. (For the given map service, this is the highest native resolution.)
The following screen shot shows the (same) given raster map service, at the (same) given AOI, but at approx 300% of native resolution. This means it is now at approx 0.3m resolution.
Some GIS viewer will "zoom in" (ie interpolate) a higher than 300%, but doing so will cause loss of visual coherency as what you had experienced or shown in your screen shots.
If you were viewing the given map service at the given extent using ArcGIS Online Viewer, then it could be that the Viewer detected that you had already reached the last layer with the highest native resolution, and instead of showing you "No Map" tiles, it interpolated that layer beyond 300%.