  A study of emission temperatures extracted from excited state populations and
of freeze out radii from light particle intensity interferometry is presented.
Three high resolution dE-E-Hodoscopes with a total of 216 detectors are
combined with the ALADiN setup in order to study Au+Au collisions at 1 A GeV.
In contrast to measurements with the isotope thermometer the extracted apparent
temperatures do not vary with impact parameter thus with excitation energy.
From the extracted radii a freeze out density was determined which decreases
from $0.2\rho_0$ for the most peripheral to less than $0.1\rho_0$ for the most
central collisions. A density--dependent feeding correction is applied to the
different temperature measurements.
