def modis( redchan, nirchan, chan3, chan4, chan5, chan6, chan7 ):
	"""
	Broadband albedo MODIS (Careful the DN multiplier! Here it is 10000.0, output range should be [0.0-1.0])
	albedo_modis( redchan, nirchan, chan3, chan4, chan5, chan6, chan7 )
	"""
	if( nirchan < 0 or redchan < 0 or chan3 < 0 or chan4 < 0 or chan5 < 0 or chan6 < 0 or chan7 < 0):
		result = -1.0
	else:
		result = ((0.22831*redchan + 0.15982*nirchan + 0.09132*(chan3+chan4+chan5) + 0.10959*chan6 + 0.22831*chan7 ) / 10000.0 )
	return result