A sparse planar array vertically placed in y − z plane is proposed to improve the angle estimation accuracy of sources in low angle region with reflection multipath. With two sizes of spatial invariances along both dimensions, the array estimates the azimuth and elevation angles using unitary ESPRIT (estimation of signal parameters via rotational invariance techniques). The first spatial invariance with a displacement of half-wavelength yields unambiguous coarse estimates of high-variance, while the second spatial invariance with much larger a displacement of subarrays obtains cyclically ambiguous fine estimates of low-variance. The final estimates are obtained by disambiguating fine estimates with coarse estimates. A novel pairing scheme is proposed to pair both the azimuth and elevation, coarse and fine angle estimates of the same signal. In addition, a new method is presented to calculate 2D angles, which substitutes the estimated elevation angle into the sin relative to the y-axis to get the azimuth angle. Employing real-valued processing and array aperture extension, the new DOA measuring method de-correlates the multipath signals and enhances angle resolution with no extra antennas and computational complexity. Simulation results show the effectiveness of the proposed technique and its advantages over the conventional methods.