Shuo-Tang / direct_position_estimation

The codes for direct position method in GNSS context

Direct Position Estimation

• Direct Position Estimation (DPE) is a high-sensitivity receiver design, particularly effective in GNSS applications. Unlike traditional methods, the DPE algorithm solves for PVT directly from raw satellite signals, bypassing the need for intermediate quantities like pseudorange and carrier phase. DPE has demonstrated superior performance in terms of precision and robustness, especially in GNSS-challenging environments.

• Our initial and "naive" idea is that traditional positioning techniques developed over past decades can also enhance the existing DPE approach. This repository includes our DPE projects, aimed at enriching the standard DPE with additional features and applications.

• Click into the project folder of the interest and look through the introductions. Or refer to our papers.

Project Folders

• standard_DPE: This folder is for the existing standard DPE approach, first proposed by Prof. Pau Closas.
  For more details or to cite this work, refer to the paper:

  Closas, P. and Gusi-Amigo, A.,
  2017. Direct position estimation of GNSS receivers: Analyzing main results, architectures, enhancements, and challenges. IEEE Signal Processing Magazine, 34(5), pp.72-84.
  

  IEEE SPM 2017: https://ieeexplore.ieee.org/abstract/document/8026199

• precise_DPE:
  This folder contains the Precise DPE (PDPE) approach, which incorporates carrier phase information into the signal model for enhanced positioning accuracy. For more details or to cite this work, refer to the paper:

  Tang, S., Li, H., Calatrava, H. and Closas, P.,
  2023, April. Precise direct position estimation: Validation experiments. In 2023 IEEE/ION Position, Location and Navigation Symposium (PLANS) (pp. 911-916). IEEE.
  

  INO PLANS 2023: https://ieeexplore.ieee.org/abstract/document/10140046

• robust_interference_mitigation:
  This folder includes the Robust DPE approach, which utilizes Zero Memory Non-Linearity (ZMNL) filters, such as estimation based on Huber's loss, to improve interference tolerance.
  For more details or to cite this work, refer to the paper:

  Li, H., Tang, S., Wu, P. and Closas, P.,
  2023. Robust interference mitigation techniques for direct position estimation. IEEE Transactions on Aerospace and Electronic Systems.
  

  IEEE TAES 2023: hhttps://ieeexplore.ieee.org/abstract/document/10242000

• multipath:
  The core concept of DPE provides natural multipath mitigation by fusing satellite information at an early stage. This folder contains plots of multipath error envelopes and an implementation of DPE in realistic multipath environments generated by LMSCM (DLR).

• SD_DPE:
  The proposed SD-DPE approach integrates differential GNSS (DGNSS) techniques into the DPE context. Specifically, it leverages the difference between the code delay of the rover and the base station at the signal level, rather than at the observable level, to reduce common errors such as ionospheric and tropospheric errors.