Timing accuracy for the simple planar propagation of magnetic field structures in the solar wind

Results from a correlation analysis of Wind and IMP 8 magnetometer data for a total of 543 two hour periods covering Jan.–Jul. 1995 were analyzed to determine that: (1) the timing accuracy Δτ for advecting solar wind magnetic field structures goes as (d per /d par ) · τ con where d par is the spacecraft separation along the Sun‐Earth line, d per is the transverse separation, and τ con is the predicted convection lag time, (2) “good” correlation time periods (peak correlation coefficient >0.80) are about twice as likely at solar maximum than at solar minimum, (3) geometry affects timing accuracy more than any propagation of features with respect to the solar wind, and (4) there is a “high” probability (greater than predicted by a Gaussian distribution) of “very bad” (|d par Δτ/d per τ con | >3) timing agreement due to the long tail on the probability distribution.