Product: TIBCO Spotfire®
How to use map data based on the NAD27 projection in TIBCO Spotfire
There may be some confusion about how to configure a map chart in TIBCO Spotfire when the data sources are based on the NAD27 projection, including where to select the correct Coordinate Reference System (CRS) and how to handle the datum shift warnings which may be displayed.
It is important that the CRS for the map layer is set to the default value of "WGS 84 - Pseudo Mercator" under Map Chart Properties > Appearance. You can also deselect the "Show datum shift warnings" option to prevent those from being displayed in the map chart:
Doc: Map Chart Properties