   getCalibration: (header) ->
     zeroPoint = header.get('MZP_AB')
     return Math.pow(10, 0.4*(30.0 - zeroPoint))
+  
+  getProvenance: (header) ->
+    return header.get('PROV')
   
   # Call when all channels are received (i.e. each deferred is resolved)
   allChannelsReceived: =>

            @cache['prefix'][band].width = width
            @cache['prefix'][band].height = height
            @cache['prefix'][band].calibration = calibration
            
            @dfs[band].resolve()
          )
  

          width = cache[band].width
          height = cache[band].height
          @calibrations[band] = cache[band].calibration
          @provenances[band] = cache[band].provenance
          
          @wfits.loadImage(band, arr, width, height)
          @dfs[band].resolve()
