def METHOD_NAME(det):
    """
    Return an array of radial distance from the focal plane center for
    each pixel in a CCD.
    Parameters
    ----------
    det : lsst.afw.cameraGeom.Detector
        CCD in the focal plane.
    """
    # Compute the distance from the center of the focal plane to
    # each pixel in the CCD, by generating the grid of pixel x-y
    # locations in the focal plane.
    bbox = det.getBBox()
    nx = bbox.getWidth()
    ny = bbox.getHeight()
    # Pixel size in mm
    pixel_size = det.getPixelSize()
    # CCD center in focal plane coordinates (mm)
    center = det.getCenter(cameraGeom.FOCAL_PLANE)
    # Pixel center x-y offsets from the CCD center in mm
    dx = pixel_size.x*(np.arange(-nx/2, nx/2, dtype=float) + 0.5)
    dy = pixel_size.y*(np.arange(-ny/2, ny/2, dtype=float) + 0.5)
    # Corner raft CCDs have integral numbers of 90 degree
    # rotations about the CCD center, so account for these when
    # computing the x-y pixel locations.
    n_rot = det.getOrientation().getNQuarter() % 4
    if n_rot == 0:
        xarr, yarr = np.meshgrid(center.x + dx, center.y + dy)
    elif n_rot == 1:
        yarr, xarr = np.meshgrid(center.y + dx, center.x - dy)
    elif n_rot == 2:
        xarr, yarr = np.meshgrid(center.x - dx, center.y - dy)
    else:
        yarr, xarr = np.meshgrid(center.y - dx, center.x + dy)
    pixel_radii = np.sqrt(xarr**2 + yarr**2)
    return pixel_radii