How to Access Indiana’s Imagery and Elevation Raster Datasets

The IGIO has received feedback from our GIS community regarding their needs for imagery products. This post serves to expand on how users can access products by download and by using the IGIO’s imagery REST services. Downloads can be made for all products through our footprint layer for both orthoimagery and Bare Earth Digital Elevation Model (DEM). These products are also available through our university partners IU Indiana Spatial Data Portal and Purdue Department of Forestry Lidar repository.

The IGIO asked how the GIS community was accessing Indiana's imagery products and here is a visualization of that breakdown:

What you need to know about the IGIO’s cached Imagery services:

• Cached Imagery Services provides 3-band pre-rendered image tiles which reduces the server processing time.

• These tiles are optimized for fast display and are suitable for base maps or static visualization.

• Cached imagery is Ideal for field web maps where internet service is spotty or unavailable or scenarios where responsiveness and speed are critical.

What you need to know about the IGIO’s dynamic Imagery services:

• Dynamic imagery services allow users to explore imagery interactively by fetching the 4-band cloud-optimized GeoTIFF (GOC) stored in our AWS Open Data account.

• Provides access to the raw pixel value of the orthoimagery or DEM elevation value.

• Within the dynamic imagery services, raster functions are applied to the imagery service before publishing the service.

What is a Raster function?

• A “Raster functions are operations that apply processing directly to the pixels of imagery and raster datasets, as opposed to geoprocessing tools, which write out a new raster to disk.” (Esri Raster function definition)

• Users can easily display multiple renderings while retaining the source image values.

• Functions can easily be interchanged using ArcGIS Pro and ArcGIS Online Maps.

• NIR and NDVI have been created from the orthoimagery products, while hill shade, shaded relief, slope, and aspect ratio functions have been applied to the elevation DEM dynamic services.

Please review the "How to use Rest Services" guide for instruction.

How to get involved:

To learn more about the various ways to use our dynamic and cached imagery service or download tiled products, please visit ourimagery hub pagededicated to this topic.