ArcGIS Server

Long name	ArcGIS Server
Short name	AGS
File extension(s)	.ags

GDB supports ESRI ArcGIS Server connections for read-only access.

An ArcGIS Server provides different types of services. GDB supports map services and image services. A map service is used to obtain backdrop images, which are not appropriate for processing. An image service is used to obtain raster data that can be processed.

GDB data model for ArcGIS Server services

ArcGIS Server map services and image services are represented in GDB as a GDB file. When a request is made to the server to get a portion of an image, a temporary file is created on disk and the GDB framework is used to open that file. Maps services produce PNG files and image services produce TIFF files. GDB uses overviews and tiling to enhance raster access performance.

ArcGIS Server data types supported by GDB

GDB supports the following ArcGIS Server data types:

Byte
Int16
UInt16
Float32
Elevation (8, 16, 32)

GDB does not support the following ArcGIS Server data types:

Int32
UInt32
Float64
CInt16
CInt32
CFloat32
CFloat64
Elevation (64)

Note: Map services always produce 3 channels of type Byte.

Opening an ArcGIS Server service from GDB

ArcGIS Server services can be accessed using the Remote Data Wzard in CATALYST Professional (see Selecting data from an ArcGIS Server service). From EASI and any other programming environment, ArcGIS Server services can be accessed by constructing a connection string (URI) indicating information such as the server name, service path, service name, connection parameters, and so on. Currently, the format supports specifying one query parameter: a spatial bounding box.

URI style connection strings

The ArcGIS Server URI connection string uses the following syntax:

ags:///<encoded service string>

When query parameters are specified, the URI has the following syntax:

ags:///<encoded service string>?<list of query components>

<encoded service string> is the ArcGIS Server service string encoded using x-www-form-urlencoded as specified by http://www.w3.org/TR/html4/interact/forms.html#.

<list of query components> is a list of key value pairs encoded using http://www.w3.org/TR/html4/interact/forms.html#.

Query components

There is currently one acceptable query component.

Query component	Description
bbox	<Bounding box> is used to select a subset of the service. The value is specified as “xmin,ymax,xmax,ymin” where xmin,ymax are the upper-left coordinate numbers of the rectangle and xmax,ymin are the lower-right coordinate numbers of the rectangle. The bbox value is optional; when it is not specified, the entire image service is returned from the server.

ArcGIS Server URI examples

The following are some examples of ArcGIS Server URIs:

Example	Description
ags:///http://services.arcgisonline.com/ArcGIS/rest/ services/Demographics/USA_1990-2000_Population_Change/MapServer	Used to access the “Demographics/USA_1990-2000_Population_Change” map service on the server “services.arcgisonline.com”.
ags:///http://gisservice.mt.gov/ArcGIS/rest/services/ADLC/ ADLC_data/MapServer	Used to access the “ADLC/ADLC_data” map service on the server “gisservice.mt.gov”.
ags:///http://imagery.arcgisonline.com/ArcGIS/rest/services/ LandsatGLS/Agriculture/ImageServer	Used to access the “LandsatGLS/Agriculture” image service on the server “imagery.arcgisonline.com”.
ags:///http://rasterevents.arcgisonline.com/ArcGIS/rest/ services/GeoEye_Imagery_Japan_After/ImageServer	Used to access the “GeoEye_Imagery_Japan_After” image service on the server “rasterevents.arcgisonline.com”.
ags:///http://imagery.arcgisonline.com/ArcGIS/rest/services/ LandsatGLS/Agriculture/ImageServer?bbox=9.5,10,10,9.5	Used to access the “LandsatGLS/Agriculture” image service on the server “imagery.arcgisonline.com” and to request only the rectangle with upper-left coordinate (9.5,10) and lower-right coordinate (10, 9.5).