What is an Image Service

Owned by Karin Stronkhorst
Last updated: 09, Aug, 2022 by Alistair Quinn (Unlicensed)
2 min read

The image and elevation services can be classified by:

Data Types - Aerial, Satellite and Elevation

Each service consists of an organised collection of Projects. A project is an image that has been captured over a fixed area across a discrete period of time - for example, aerial photography of a single town taken in one day. Thus an AerialOrtho service consists of imagery captured by remotely piloted aircraft systems such as drones or planes.

Access Types - Public or Restricted

Public services can be access by everyone and you do not need to Sign In to the Spatial Portal, just connect to it. Public services are named with the suffix _AllUsers.

Restricted services can be accessed when you are a member of the SISP or CLP programs, or within the Queensland Government network. Depending on the type of data in the service, it will be named with the suffix _SISPUsers, _QGovSISPUsers or _CLPUsers.

Service Types - Basemap, TimeSeries and Elevation

Basemap services comprise a single layer of static imagery optimised for display purposes at one location. Basemaps often have an embedded tile_cache which allows imagery to load quickly thus perform better.  
In ESRI desktop software non-elevation tile_caches can be disabled for display beyond the lowest cache level, where as in Map Viewers and in non-ESRI software a dynamic service can be placed underneath the tile_cached services for this purpose.

 

Time Series services are comprised of multiple layers of project imagery from different epochs all stacked on top of each other at one location. These services are dynamic and allow users to perform queries and analysis on the various imagery layers.  As a result these services are slower in performing.

 

Elevation services contain the highest resolution, ortho Digital Elevation Model (DEM) data captured by LiDAR systems. The Time Series versions contains Aspect, Hillshade, Slope_degrees and Slope_percent_rise rendering functions.