Survey window functions for the W1 and W4 samples at 0.6 < z < 0.9, projected along the k_x, k_y, k_z directions; the dashed lines correspond to considering only the geometry of the parent sample, while the solid lines give the final window function, when the small-scale angular features of the mask are included. The two samples at 0.9 < z < 1.1 show approximately similar window functions.