Weak-lensing Power Spectrum Reconstruction by Counting Galaxies. II. Improving the ABS Method with the Shift Parameter

In Paper I of this series, we proposed an analytical method of blind separation (ABS) to extract the cosmic magnification signal in galaxy number distribution and reconstruct the weak-lensing power spectrum. Here, we report a new version of the ABS method with significantly improved performance. This version is characterized by a shift parameter, { \mathcal S }, with the special case of { \mathcal S }=0 corresponding to the original ABS method. We have tested this new version, compared it with the previous one, and confirmed its superior performance in all investigated situations. Therefore, it supercedes the previous version. The proof of concept studies presented in this paper demonstrate that it may enable surveys such as LSST and SKA to reconstruct the lensing power spectrum at z ≃ 1 with 1% accuracy. We will test the new ABS method in more realistic simulations to verify its applicability to real data.