PPPx_bin

PPPx is a versatile multi-GNSS data processing software package. Its capabilities go beyond Precise Point Positioning (PPP).

The main program, pppx, focuses on positioning and supports the following features:

• Solution modes:
  • SPP: Single Point Positioning
  • PPP: Precise Point Positioning
  • RTK: short baseline processing
  • TDP: Time-Differenced Positioning
• GNSS systems: GPS, GLONASS, Galileo, Beidou-2/3, QZSS
• Solvers: LSQ, EKF and FGO
• PPP-AR with OSB products (.BIA)
• Flexible frequency selection: L1/L2/L5/E1/E5a/...
• High precision and efficiency: Capable of processing 2880 epochs within 2 seconds
• Unified input/output format

Other programs in the PPPx software package include:

• clkcomb: A program for combining PPP-AR products
• seid: An implemation of the SEID method

Installation

Linux

pppx is recommendeded for use on Ubuntu, as the binary was built with gcc 11 on Ubuntu 22.04. However, it should work on most modern Linux systems with gcc 11 available.

The executable bin/pppx is dynamically linked to the ceres solver, so the library libceres-dev must be installed first. The installation on Linux can be done with the following commands:

sudo apt install libceres-dev
git clone git@github.com:YuanxinPan/PPPx_bin.git

mkdir -p ${HOME}/.local/bin
cp PPPx_bin/bin/pppx ${HOME}/.local/bin/
echo "export PATH=\${HOME}/.local/bin:\$PATH" >> ${ HOME}/.bashrc
# Restart your terminal afterward

If you don't have the sudo privilege and cannot install libceres-dev, you can use the static build bin/pppx\_static, though this version does not support FGO.

Windows

The easiest way to run pppx on Windows is via the Windows Subsystem for Linux (WSL).

Usage

The general steps to process GNSS data with pppx are:

1. Prepare RINEX observation files and necessary products (either broadcast ephemeris or precise products)
2. Modify the configuration file pppx.ini
3. Execute pppx with the appropriate command-line arguments:

pppx path-to-rnxo [rnxo-of-base] pppx.ini

# Example usage:

# For SPP/PPP/TDP  (Note: TDP is suitable for high-frequency data, e.g., 1 Hz)
pppx rinex/ZIM200CHE_R_20221000000_01D_30S_MO.rnx pppx.ini

# For RTK (ZIMM is the base station in this example)
pppx rinex/ZIM200CHE_R_20221000000_01D_30S_MO.rnx rinex/ZIMM00CHE_R_20221000000_01D_30S_MO.rnx pppx.ini

Input

1. Configuration file: pppx.ini
2. GNSS observations: RINEX format
3. Satellite products: Broadcast ephemeris or precise products, specified in pppx.ini
4. Table files: Provided in the table directory, specified in pppx.ini

Output

1. pos file: Receiver position, clock, and ZTD estimates for each epoch
2. log file: Debugging information
3. stat file: Postfit residuals and various estimates in the RTKLIB stat format, for visualization with RTKLIB

Visualization

With python

# To plot position estimates only
python scripts/plot_ppppos.py pos_file

# To plot position, receiver clock and ZTD estimates
python scripts/plot_ppppos.py pos_file -a

# -a  Plot receiver position, clock, and ZTD estimates
# -i  Interactive mode
# -s  Fixed scale for the y-axis; otherwise, scale is set automatically

With RTKLIB

For enhanced interactive viewing and visualization of postfit residuals:

1. Open the rtkplot.exe application
2. Navigate to "File" > "Open Solution-1" and select the generated stat file
3. Interactively view various plots

Example

To help you get started, several examples are available in the example/pppx folder. Additionally, an example demonstrating pppx processing of GNSS data collected by Android smartphones is provided in the example/smartphone folder. Please execute the correspoding run.sh script to see how pppx works:

cd example/pppx/
./run.sh   # processing & plotting

For instance, the following is a visualization of a kinematic PPP solution for the ZIM2 station, using FGO and GPS+Galileo observations:

Contributing

if you have suggestions or encounter issues related to the usage of the PPPx software, please create an issue.

Author

• Yuanxin Pan - YuanxinPan

License

This project is licensed under the GPLv3 License - see the LICENSE file for details.