0

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.

enter image description here

enter image description here

enter image description here

enter image description here

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.

enter image description hereenter image description here

Can anybody successfully see a 0.3m resolution imagery as a basemap or through any of the services?

Two ways to reproduce this issue:

Here is a list of posts pointing to the same problem:

  • If anybody can see the high resolution imagery in their World Imagery basemap or through the gis services please share it with us. Thanks! – ZZZ Mar 25 '18 at 18:01
  • The higher resolution data is both from a previous provider and too old. – Vince Mar 25 '18 at 21:39
  • In the metadata link it says that 0.3m imagery is still a part of the World Imagery. The reply from Esri is that it is available under Clarity (last link in the original post). But it is not. Then the question is how to get access to the 0.3m resolution imagery? – ZZZ Mar 25 '18 at 23:46
  • 3
    Per information here: developers.arcgis.com/documentation/tiled-elevation-service - And snooping requests while zooming in around that area, you'll see at tile level 20 a tilemap request is being made, with [0,0,0,..0] being returned. This indicates that tiles are not available for this location/zoom level. Why? I dont know. Should they? I dont know. – KHibma Mar 26 '18 at 12:40
  • I think the question is basically: "Is Esri high resolution imagery service still available?" It seems that the answer is NO. – arkaia Mar 28 '18 at 1:36
1

Can anybody successfully access the high resolution imagery as a basemap or through any of the services?

"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.)

enter image description here

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.

enter image description here

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%.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.