Real-Time Global Live Satellite Monitoring App

An application that fetches live global satellite positions and visualises them on an interactive world map in real time, all 195 Countries.

Live Satellite Tracker is a fully functional MATLAB App Designer application for real-time satellite tracking over any country in the world. The app connects to the N2YO REST API using MATLAB's built-in webread() function to retrieve live orbital data — no third-party toolboxes or external libraries required.

OVERVIEW

The app presents a clean two-tab interface. The Home tab contains an interactive UIAxes map, a country selector dropdown covering 195 countries, a satellite category dropdown (All Satellites, Starlink, GPS, ISS, Weather, NOAA, and more), a search radius knob (0–90 degrees), configurable max-distance and max-satellite-count fields, and four action buttons — Play, Refresh, Export, and Stop. The Reports tab displays a sortable UITable with full per-satellite data.

HOW IT WORKS

1. Country selection: the user selects a country from a dropdown. The app instantly resolves the country's geographic centre coordinates (latitude and longitude) from a built-in lookup table covering all 195 UN-recognised countries.

2. API call: pressing Play sends a live HTTP request to the N2YO /above/ endpoint, querying for all satellites visible above the selected location within the configured search radius and category. The full URL is constructed programmatically using sprintf() and executed via webread() with a weboptions timeout.

3. Data parsing: the JSON response is parsed into a structured MATLAB table with columns for Satellite ID, Satellite Name, Latitude, Longitude, Altitude (km), Speed (km/s), Distance from country centre (km), and Launch Date.

4. Haversine distance filter: a custom haversine() function computes the great-circle distance between each satellite's current ground position and the selected country's centre. Only satellites within the user-defined maximum distance are retained.

5. Speed calculation: orbital speed is derived analytically from altitude using the vis-viva equation — v = sqrt(GM / (Re + alt)) — giving an accurate approximation for circular low Earth orbits without requiring any additional data field from the API.

6. Map visualisation: satellites are rendered on app.UIAxes as a colour-coded scatter plot. Marker colour encodes altitude (dark blue = low orbit, cyan = high orbit) and marker size encodes proximity (larger = closer to the country centre). The top 8 nearest satellites are labelled with name, altitude, and speed. A gold star marks the country's geographic centre. An orange ring highlights the single nearest satellite with its distance.

7. Auto-refresh: a MATLAB timer() object running in fixedRate mode triggers a full data fetch and map redraw every 30 seconds. The lamp indicator shows the app state — red (idle), yellow (fetching), cyan (country ready), green (data loaded).

8. Export: every refresh automatically writes the current satellite table to a CSV file using writetable(), compatible with Microsoft Excel and Google Sheets.

TECHNICAL HIGHLIGHTS

• Zero external toolboxes required for core functionality (Mapping Toolbox used optionally for coastline rendering; falls back to a grid overlay if unavailable)
• Fully event-driven architecture using App Designer callbacks and MATLAB timer objects
• Robust error handling with uialert dialogs, lamp state feedback, and graceful API timeout management
• Supports all N2YO satellite categories including Starlink, OneWeb, GPS, GLONASS, Galileo, ISS, Hubble, Weather, NOAA, and Amateur Radio satellites
• Clean shutdown: CloseRequestFcn stops and deletes the timer before app deletion, preventing orphaned timer objects

WHAT YOU CAN DO WITH THIS APP

• Track the International Space Station (ISS) passing over your country
• Monitor Starlink constellation density over any region
• Identify GPS and GLONASS satellites currently serving your location
• Study LEO vs GEO satellite distribution by altitude
• Export time-series snapshots to CSV for further analysis in MATLAB or Excel