ArcGIS GeoAnalytics Server tasks that have the processSR property in the Context parameter will analyze features in the specified spatial reference. If you are saving the results to the spatiotemporal data store results will always be projected to World Geographic Coordinate System 1984 after analysis for storage.
Process spatial reference syntax:"processSR": {"wkid": <wkid>}
wkid is the well-known integer ID of a spatial reference. See Using spatial references for the list of supported spatial references and their IDs. Many analytics require using a projected coordinate system to calculate results.
Spatial Reference example (GCS_WGS_1984)"processSR": {"wkid": 4326}
You may use a different spatial reference for analysis (processSR) and for defining the processing extent(See: Extent). For example, you can define the extent in wkid 4326 (GDC_WGS_1984) and analyze in wkid 3857 (WGS_1984 Web Mercator - auxiliary sphere):
Extent and processSR example:
"context" : {
"extent": {
"xmin": -122.68,
"ymin": 45.53,
"xmax": -122.45,
"ymax": 45.6,
"spatialReference": {
"wkid": 4326
}
},
"processSR": {"wkid": 3857}
}