MEM --- The Maximum Entropy Method

INTRODUCTION

• Developed by Jaynes (1957), (1978)
• Founded on probability theory (Gull & Skilling)
• Confidence testing possible in a rigorous way (in principle, if not practice)
• Other uses are rich and diverse; a few listed here:
  • Radio astronomy Uvashi & Cornwell, NRAO, Robishaw, BIMA
  • DNA sequencing (autoradiograph improvement)
  • Tomography 3-D Doctor , Beam tomography PSI
  • Remote sensing GOES MODIS, Landsat, SPOT, etc
  • Reaction kinetics, PET scans (Steinbach)
• Two versions in the RHESSI release software
  • MEM_SATO --- based on HXT MEM program (J. McTiernan)
  • MEM_VIS --- Uses "visibilities" A. Conway
• Problems
  • Super resolution --- brightness is not constrained
  • Relative weight of Entropy & Chisquare not optimized (Lnorm)
  • MEM_VIS has problems with multiple rotations
  • Confidence testing not fully implemented
• Bayesian derivation of MEM
• Using MEM_SATO

REFERENCES FOR THE CURIOUS