This paper is concerned with developing methods for the propagation of
linear waves in several space dimensions. The methods are time revers
ible and hence are free from numerical dissipation. They are based on
bicharacteristic forms of the governing equations and are made possibl
e by adopting forms of staggered storage that depend on the precise eq
uations under consideration. Analysis is presented for the equations o
f acoustics, electromagnetics, and elastodynamics.