  We describe an improved technique for using the backscattered phase from
meteor radar echo measurements just prior to the specular point ($t_{0}$) to
calculate meteor speeds and their uncertainty. Our method, which builds on
earlier work of Cervera et al (1997), scans possible speeds in the Fresnel
distance - time domain with a dynamic, sliding window and derives a best-speed
estimate from the resultant speed distribution. We test the performance of our
method, called pre-$t_{0}$ speeds by sliding-slopes technique (PSSST), on
transverse scattered meteor echoes observed by the Middle Atmosphere Alomar
Radar System (MAARSY) and the Canadian Meteor Orbit Radar (CMOR), and compare
the results to time-of-flight and Fresnel transform speed estimates. Our novel
technique is shown to produce good results when compared to both model and
speed measurements using other techniques. We show that our speed precision is
$\pm$5$\%$ at speeds less than 40 km/s and we find that more than 90$\%$ of all
CMOR multi-station echoes have PSSST solutions. For CMOR data, PSSST is robust
against the selection of critical phase value and poor phase unwrapping. Pick
errors of up to $\pm$6 pulses for meteor speeds less than about 50 km/s produce
errors of less than $\pm$5$\%$ of the meteoroid speed. In addition, the width
of the PSSST speed Kernel density estimate (KDE) is used as a natural measure
of uncertainty that captures both noise and $t_0$ pick uncertainties.
