Synthetic aperture ladar (SAL) is a combination of synthetic aperture and ladar, which has developed rapidly in recent years. Since the wavelength of the SAL is short, high-resolution imaging can be achieved in a short period of time. However, short wavelength also brings other problems. For airborne SAL, the wavelength is less than the vibration amplitude of the airplane by 1-2 order of magnitude, and the vibration of the airplane results in a great phase error to the echo. It is difficult for the inertial navigation system (INS) to achieve the positioning accuracy at the laser wavelength level, so the data-based self-focusing is necessary in SAL imaging. In this paper, a full aperture imaging algorithm based on minimum entropy autofocus (MEA) and deramp is proposed to process the SAL real data. The imaging results verify the effectiveness of the proposed algorithm.