Track edge magnetization structures for a single-layered perpendicular media recorded with ring-type head are observed by magnetic force microscopy (MFM). Quantitative analysis of the microscopic magnetization structure is carried out through spectrum analyses of the MFM images. Magnetization structures with sharp track edge profile are formed by using a trimmed symmetrical pole tip shap write head. Several peaks in the Fourier-transformed spectra are considered to reflect the presence of magnetization irregularities. Medium noise measured at the recorded track edge is about 2.6dB larger than that measured from the DC-erased area.