We present the analysis of the binary gravitational microlensing event MOA-2015-BLG-020 .
The event has a fairly long timescale ( \sim 63 days ) and thus the light curve deviates significantly from the lensing model that is based on the rectilinear lens-source relative motion .
This enables us to measure the microlensing parallax through the annual parallax effect .
The microlensing parallax parameters constrained by the ground-based data are confirmed by the Spitzer observations through the satellite parallax method .
By additionally measuring the angular Einstein radius from the analysis of the resolved caustic crossing , the physical parameters of the lens are determined .
It is found that the binary lens is composed of two dwarf stars with masses M _ { 1 } = 0.606 \pm 0.028 M _ { \odot } and M _ { 2 } = 0.125 \pm 0.006 M _ { \odot } in the Galactic disk .
Assuming the source star is at the same distance as the bulge red clump stars , we find the lens is at a distance D _ { L } = 2.44 \pm 0.10 \text { kpc } .
In the end , we provide a summary and short discussion of all published microlensing events in which the annual parallax effect is confirmed by other independent observations .