  Proton deflectometry is increasingly used in magnetized high-energy-density
plasmas to observe electromagnetic fields. We describe a reconstruction
algorithm to recover the electromagnetic fields from proton fluence data in
1-D. The algorithm is verified against analytic solutions and applied to
example data. Secondly, we study the role of source fluence uncertainty for 1-D
reconstructions. We show that reconstruction boundary conditions can be used to
constrain the source fluence profile, and use this to develop a reconstruction
using a specified pair of boundary conditions on the magnetic field. From these
considerations we experimentally demonstrate a hybrid mesh-fluence
reconstruction technique where fields are reconstructed from fluence data in an
interior region with boundary conditions supplied by direct mesh measurements
at the boundary.
