Release 1 (2021-04-20) of the magnetic field KT17 model residuals (DELTA_B) data bundle. 
  The residuals represent the difference between the magnetic field observed 
  by the MESSENGER Magnetometer (MAG) and the modeled magnetic field computed 
  from the Korth et al. [2017] magnetospheric magnetic field model. This 
  release contains the Reduced Data Record (RDR) products for the data-sci-mbf 
  and data-sci-mso collections along with the documentation required for the 
  bundle.