partially solves
@@ -378,7 +378,7 @@ class Periodogram(object):
raise ValueError("the 'boxkernel' method requires the periodogram "
"to have a grid of evenly spaced frequencies.")
- box_kernel = Box1DKernel(np.ceil(filter_width/fs))
+ box_kernel = Box1DKernel(np.ceil(filter_width.value/fs.value))
smooth_power = convolve(self.power.value, box_kernel)
smooth_pg = self.copy()
smooth_pg.power = u.Quantity(smooth_power, self.power.unit)
