We develop a numerical scheme to make a high-frequency skymap of gravitational-wave backgrounds ( GWBs ) observed via space-based interferometer .
Based on the cross-correlation technique , the intensity distribution of anisotropic GWB can be directly reconstructed from the time-ordered data of cross-correlation signals , with full knowledge of detector ’ s antenna pattern functions .
We demonstrate how the planned space interferometer , LISA , can make a skymap of GWB for a specific example of anisotropic signals .
At the frequency higher than the characteristic frequency f _ { * } = 1 / ( 2 \pi L ) , where L is the arm-length of the detector , the reconstructed skymap free from the instrumental noise potentially reaches the angular resolution up to the multipoles \ell \sim 10 .
The presence of instrumental noises degrades the angular resolution .
The resultant skymap has angular resolution with multipoles \ell \leq 6 \sim 7 for the anisotropic signals with signal-to-noise ratio S/N > 5 .