Precise indoor altitude estimation based on differential barometric sensing for wireless medical applications. - Christian Bollmeyer; Tim Esemann; Hartmut Gehring; Horst Hellbrück (BSN, 2013)

Evaluation of radio based, optical and barometric localization for indoor altitude estimation in medical applications. - Christian Bollmeyer; Mathias Pelka; Hartmut Gehring; Horst Hellbrück (IPIN, 2014)

Accurate radio distance estimation by phase measurements with multiple frequencies. - Mathias Pelka; Christian Bollmeyer; Horst Hellbrück (IPIN, 2014)

Indoor localization based on bi-phase measurements for wireless sensor networks. - Mathias Pelka; Christian Bollmeyer; Horst Hellbrück (WCNC, 2015)