  We present the first accurate characterization of high-degree modes, derived
using the best MDI full-disk full-resolution data set available. A ninety day
long time series of full-disk two arc-second per pixel resolution dopplergrams
was acquired in 2001. These dopplergrams were spatially decomposed using our
best estimate of the image scale and the known components of MDI's image
distortion. A multi-taper power spectrum estimator was used to generate power
spectra up to l = 1000, with a large number of tapers to reduce the realization
noise, while the blending at high degrees negates the need for high spectral
resolution. These power spectra were fitted for all degrees and all azimuthal
orders, between l = 100 and l = 1000. This fitting generated in excess of
6x10^6 individual estimates of ridge frequencies, line-widths, amplitudes and
asymmetries (singlets: l,n,m), corresponding to some 6,000 multiplets (l,n).
Fitting at high degrees generates ridge characteristics, characteristics that
do not correspond to the underlying mode characteristics. We used a
sophisticated forward modeling to recover the best possible estimate of the
underlying mode characteristics (mode frequencies, as well as line-widths,
amplitudes and asymmetries). We describe in detail this modeling and its
validation. The modeling has been extensively reviewed and refined, by
including an iterative process to improve its input parameters to better match
the observations. Also, the contribution of the leakage matrix on the accuracy
of the procedure has been carefully assessed. We present the derived set of
corrected mode characteristics, discuss their uncertainties and the precision
of the ridge to mode correction schemes. In our conclusions, we address how to
further improve these estimates, and the implications for other data sets, like
GONG+ and HMI.
