HMI Synoptic Maps Produced by NSO/NISP
  Recently, the National Solar Observatory (NSO) Solar-atmosphere Pipeline Working Group has undertaken the production of synoptic maps from Helioseismic and Magnetic Imager (HMI) magnetograms. A set of maps has been processed spanning the data available for 2010-2015 using twice daily images (taken at UT midnight and noon) and running them through the same algorithms used to produce SOLIS/VSM 6302l mean-magnetic and spatial-variance maps. The contents of this document provide an overview of what these maps look like, and the processing steps used to generate them from the original HMI input data. 
Anna L. H. Hughes, Luca Bertello, Andrew R. Marble, Niles A. Oien,   Gordon Petrie, and Alexei A. Pevtsov
astro-ph.IM astro-ph.SR