  Signals with single peak and symmetry property are very common in various
fields, such as probability density function of normal distribution. Among the
information contained in such signals, peak position is the most important,
sometimes even the only parameter concerned. Current methods for peak position
estimation are always with low precision and bad noise resistance, perform
badly for sparse spectrum. This manuscript proposes two new algorithms that
take advantage of symmetry property, conduct mirroring and interpolating
operations to condense signal spectrum. From tests done in this paper, these
two algorithms indicate outstanding advantages compared with current methods.
