@Article{	  schaefer18ral,
  author	= {A. Schaefer and L. Luft and W. Burgard},
  journal	= {IEEE Robotics and Automation Letters (RA-L)},
  title		= {{DCT} Maps: {compact} Differentiable Lidar Maps Based on
		  the Cosine Transform},
  year		= {2018},
  volume	= {3},
  number	= {2},
  pages		= {1002-1009},
  doi		= {10.1109/LRA.2018.2794602},
  issn		= {},
  month		= {April},
  url		= {http://ais.informatik.uni-freiburg.de/publications/papers/schaefer18ral.pdf}
}