An X-Windows manager is required for Macintosh. The software products were tested using XQuartz 2.7.4. For optimal performance, your video card should have a minimum of 1 GB of RAM and should support OpenGL 2.0 or later. Also be sure to install the latest drivers for your video card. An HTML5-compatible browser is required to view the ENVI Help. ENVI 5.2, Service Pack 1 includes the new and enhanced features listed below. See the following sections: The ENVI Orthorectification Module supports the following sensors: AlSat-2A, Gaofen-1, GeoEye-1 in DigitalGlobe format, Landsat-8, Pleiades-1A, SPOT-6/7 DIMAP, VNREDSat-1, WorldView-3, Ziyuan-1-02C, and Ziyuan-3A. Use the Radar Backscatter tool to calibrate a radar amplitude raster to sigma nought backscatter, in decibels. It currently only works with ALOS-1 or ALOS-2 PALSAR Level-1.5, 2.5, and 3.1 data. ArcGIS Image Services that require an ArcGIS portal account or ArcGIS online account are now supported. Image Service catalog items are also supported. Real-time Ortho is a new feature for digitized vector and ROI layers. In previous versions of ENVI, any digitized vector or ROI layer that was created on top of an image containing RPC coefficients produced only pixel-based, unprojected geometry. While you could use these vector and ROI layers with the RPC image, they did not contain projection information that allowed them to relate to other images. Also, if you displayed a projected layer in the same view as an unprojected RPC image, the RPC image reprojected into the newly established base projection. Now, with Real-time Ortho, vector and ROI layers created on top of an RPC image will contain projected coordinates that can display with other projected imagery, and projected vector and ROI layers will display on top of an existing RPC image without reprojecting the RPC image. If you display two RPC images in the same view, ENVI will automatically reproject the imagery to a geographic Lat/Lon WGS-84 coordinate system to allow ENVI to work in GCS_WGS_1984 mode. Geographic reprojection is the default setting for the new Base Projection for the Non-Standard Rasters preference, you can change the default to UTM, if desired. You can create custom data-processing tasks using IDL and ENVI application programming interface (API) code. If you also use the ENVI Services Engine (ESE), the custom tasks will be available in the ESE Admin Console so that you can process data as a web service. Source.