docs: def getGeometry(self,ra=None,dec=None):
          """Return an array of rectangles that represent the 'ra,dec' corners of the FOV"""
  
          import math,ephem
          ccds=[]
  
          if ra is None:
              ra=self.ra
          if dec is None:
              dec=self.dec
          self.ra=ephem.hours(ra)
          self.dec=ephem.degrees(dec)
          for geo in self.geometry[self.camera]:
              ycen=math.radians(geo["dec"])+dec
              xcen=math.radians(geo["ra"])/math.cos(ycen)+ra
              dy=math.radians(geo["ddec"])
              dx=math.radians(geo["dra"]/math.cos(ycen))
              ccds.append([xcen-dx/2.0,ycen-dy/2.0,xcen+dx/2.0,ycen+dy/2.0])
  
          return ccds