AAE6102 Assignment 1

Satellite Communication and Navigation (2024/25 Semester 2)

The Hong Kong Polytechnic University

Department of Aeronautical and Aviation Engineering

Due Date: 13 March 2025

Overview

This assignment focuses on processing GNSS Software-Defined Receiver (SDR) signals to develop a deeper understanding of GNSS signal processing. Students will analyze two real Intermediate Frequency (IF) datasets collected in different environments: open-sky and urban. The urban dataset contains multipath and non-line-of-sight (NLOS) effects, which can degrade positioning accuracy.

Dataset Information

Environment	Carrier Frequency	IF Frequency	Sampling Frequency	Data Format	Ground Truth Coordinates	Data Length	Collection Date (UTC)
Open-Sky	1575.42 MHz	4.58 MHz	58 MHz	8-bit I/Q samples	(22.328444770087565, 114.1713630049711)	90 seconds	14/10/2021 12.21pm
Urban	1575.42 MHz	0 MHz	26 MHz	8-bit I/Q samples	(22.3198722, 114.209101777778)	90 seconds	07/06/2019 04.49am

Assignment Tasks

Task 1 – Acquisition

Process the IF data using a GNSS SDR and generate the initial acquisition results.

Task 2 – Tracking

Adapt the tracking loop (DLL) to generate correlation plots and analyze the tracking performance. Discuss the impact of urban interference on the correlation peaks. (Multiple correlators must be implemented for plotting the correlation function.)

Task 3 – Navigation Data Decoding

Decode the navigation message and extract key parameters, such as ephemeris data, for at least one satellite.

Task 4 – Position and Velocity Estimation

Using pseudorange measurements from tracking, implement the Weighted Least Squares (WLS) algorithm to compute the user's position and velocity.

• Plot the user position and velocity.
• Compare the results with the ground truth.
• Discuss the impact of multipath effects on the WLS solution.

Task 5 – Kalman Filter-Based Positioning

Develop an Extended Kalman Filter (EKF) using pseudorange and Doppler measurements to estimate user position and velocity.

Submission Guidelines

• Submit a technical report and source code via GitHub (Readme.md format).
• Share the GitHub repository link via email with:
  • Dr. Hoi-Fung Ng ([email protected])
  • Other teaching assistants
  • The course lecturer
• Deadline: 13 March 2025

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This repository contains the source code and documentation for Assignment 1 of AAE6102.