FME considers a dataset to be a folder name. The names of the NITF output files written to the output dataset folder are determined from the fme_raster_filename attribute or from the FME Feature Type. The destination folder does not have to exist before the translation occurs. Any existing files in the folder which have the same name are overwritten with the new feature data. The NITF writer distinguishes duplicate output files by appending numbers to the filenames. Please see About FME Rasters for details.
At this time, writing georeferenced NITF files can be done only using Latitude/Longitude and Universal Transverse Mercator (UTM) projections with the WGS-1984 datum. If the source data does not contain information satisfying these criteria, FME will automatically try to reproject the data before writing the file. If this reprojection fails or if the source data is not georeferenced, the destination file will not be georeferenced.