Grid-based approach for the LOP field selection, step 1 (coarse grid). A coarse grid is defined within the allowed regions at |β| > 63° (pink circle) from a HEALPix level-3 scheme in Galactic coordinates. The 86 grid points, corresponding to the centers of 86 possible PF choices, are color-coded according to the number of P1 targets available within each field. The grid points not meeting the science requirement of > 7500 P1 targets per field are marked with a cross, while the 32 surviving fields are labeled with the percentage increase of P1 targets with respect to the minimum requirement. The background gray layer is color-coded according to the areal density of G < 13.5 stars from Gaia EDR3. The TESS CVZ at |β|≳ 78° (yellow circle), the Kepler footprint (lilac region), and the centers of the previous provisional fields LOPN0 and LOPS0 (black empty diamond points) are also shown.