Table of Contents

Original Articles

• Open Access

  First results from three years of GNSS interference monitoring from low Earth orbit

  Matthew J. Murrian, Lakshay Narula, Peter A. Iannucci, Scott Budzien, Brady W. O’Hanlon, Mark L. Psiaki and Todd E. Humphreys

  NAVIGATION: Journal of the Institute of Navigation December 2021, 68 (4) 673-685; DOI: https://doi.org/10.1002/navi.449
• Open Access

  Autonomous orbit determination and timekeeping in lunar distant retrograde orbits by observing X-ray pulsars

  Jiangkai Liu, Wenbin Wang, Hao Zhang, Leizheng Shu and Yang Gao

  NAVIGATION: Journal of the Institute of Navigation December 2021, 68 (4) 687-708; DOI: https://doi.org/10.1002/navi.451
• Open Access

  A particle-filtering framework for integrity risk of GNSS-camera sensor fusion

  Adyasha Mohanty, Shubh Gupta and Grace Xingxin Gao

  NAVIGATION: Journal of the Institute of Navigation December 2021, 68 (4) 709-726; DOI: https://doi.org/10.1002/navi.455
• Open Access

  Urban positioning: 3D mapping-aided GNSS using dual-frequency pseudorange measurements from smartphones

  Hoi-Fung Ng, Guohao Zhang, Yiran Luo and Li-Ta Hsu

  NAVIGATION: Journal of the Institute of Navigation December 2021, 68 (4) 727-749; DOI: https://doi.org/10.1002/navi.448
• Open Access

  Study of structures of the sporadic E layer by using dense GNSS network observations

  Susumu Saito, Keisuke Hosokawa, Jun Sakai and Ichiro Tomizawa

  NAVIGATION: Journal of the Institute of Navigation December 2021, 68 (4) 751-758; DOI: https://doi.org/10.1002/navi.454
• Open Access

  PPP/PPP-RTK open formats: Overview, comparison, and proposal for an interoperable message

  Rui Hirokawa, Ignacio Fernández-Hernández and Simon Reynolds

  NAVIGATION: Journal of the Institute of Navigation December 2021, 68 (4) 759-778; DOI: https://doi.org/10.1002/navi.452
• Open Access

  Advanced and versatile signal conditioning for GNSS receivers using the high-rate DFT-based data manipulator (HDDM)

  Johannes Rossouw van der Merwe, Fabio Garzia, Alexander Rügamer and Wolfgang Felber

  NAVIGATION: Journal of the Institute of Navigation December 2021, 68 (4) 779-797; DOI: https://doi.org/10.1002/navi.441
• Open Access

  Improved high-precision GNSS navigation with a passive hydrogen maser

  Thomas Krawinkel and Steffen Schön

  NAVIGATION: Journal of the Institute of Navigation December 2021, 68 (4) 799-814; DOI: https://doi.org/10.1002/navi.444
• Open Access

  A multi-frequency method to improve the long-term estimation of GNSS clock corrections and phase biases

  A. Rovira-Garcia, J. M. Juan, J. Sanz, G. González-Casado, J. Ventura-Traveset, L. Cacciapuoti and E. Schoenemann

  NAVIGATION: Journal of the Institute of Navigation December 2021, 68 (4) 815-828; DOI: https://doi.org/10.1002/navi.453
• Open Access

  Positioning with medium frequency R-Mode

  Lars Grundhöfer, Filippo Giacomo Rizzi, Stefan Gewies, Michael Hoppe, Jesper Bäckstedt, Marek Dziewicki and Giovanni Del Galdo

  NAVIGATION: Journal of the Institute of Navigation December 2021, 68 (4) 829-841; DOI: https://doi.org/10.1002/navi.450