  MUSYC (MUltiwavelength Survey by Yale and Chile), and its predecessor, the
CYDER (Cal'an Yale Deep Extragalactic Research) survey are both deep
multiwavelength surveys mainly aiming at extragalactic issues; however they
were both designed with a strong Galactic component in mind. Therefore they
consist not only of multipassband imaging (UBVRIzJK) and wide field multi
object spectroscopy - it is also foreseen to create a multi-epoch dataset, thus
allowing proper motions to be derived using data of 1 and 4-5 years baseline.
This enables us to identify fast moving objects, and derive tangential
velocities of nearby and intrinsically faint objects, such as White Dwarfs
(especially cool WDs) and Brown Dwarfs (BDs). For the former, we will be able
to study the faint end of the halo-field luminosity function and determine the
fraction of baryonic dark matter consisting of WDs. We will be able to put
constraints on the volume density of BDs, and determine whether this density
actually meets expectations. Here we give a report of work in progress.
