  Excitation functions of the spin correlation coefficients
A_{NN}(p_{lab},theta_{c.m.}), A_{SS}(p_{lab},theta_{c.m.}), and
A_{SL}(p_{lab},theta_{c.m.}) have been measured with the polarized proton beam
of the Cooler Synchrotron COSY and an internal polarized atomic beam target.
Data were taken continuously during the acceleration for proton momenta p_{lab}
ranging from 1000 to 3300 MeV/c (kinetic energies T_{lab} 450 - 2500 MeV) as
well as for discrete momenta of 1430 MeV/c and above 2000 MeV/c covering angles
theta_{c.m.} between 30 deg and 90 deg. The data are of high internal
consistency. Whereas A_{SL}(p_{lab,}theta_{c.m.}) is small and without
structures in the whole range, A_{NN} and even more A_{SS} show a pronounced
energy dependence. The angular distributions for A_{SS} are at variance with
predictions of existing phase shift analyses at energies beyond 800 MeV. The
impact of our results on phase shift solutions is discussed. The direct
reconstruction of the scattering amplitudes from all available pp elastic
scattering data considerably reduces the ambiguities of solutions.
