  A scan of the top quark pair production threshold at a future
electron-positron collider provides the possibility for high-precision
measurements of the top quark mass, and, when using two dimensional fits of the
measured cross sections, also of other properties such as the width and the
Yukawa coupling. The energy range of the scan and the distribution of the
integrated luminosity can be optimized depending on the main goals of the
threshold program. This contribution examines the possibility to determine the
top quark mass in fast exploratory measurements with an adequate precision to
enable such an optimization, and studies a scanning program with a reduced
energy range of 6 GeV for the measurement of the mass, width and the Yukawa
coupling, taking theoretical uncertainties from QCD scale variations and
parametric uncertainties from the strong coupling constant into account.
