*Question E2D04:
What technology is used for real-time tracking of balloons carrying amateur radio transmitters?*  

*Correct Answer is  C: APRS*  

### AI Response: (may contain errors)  

To understand the correct answer to the question about real-time tracking of balloons carrying amateur radio transmitters, let's break down the options:

### Correct Answer: C: APRS

- **APRS (Automatic Packet Reporting System)** is a digital communication protocol used in amateur radio for real-time information sharing, including position tracking. It allows users to send and receive location data, which is ideal for tracking balloons equipped with amateur radio transmitters. APRS uses packet radio to transmit data, making it suitable for real-time applications.

### Why the Other Choices are Incorrect:

- **A: FT8**
  - FT8 is a digital mode used primarily for weak signal communication in amateur radio. It is not designed for real-time tracking but rather for making contacts over long distances with minimal power. It does not provide location tracking capabilities.

- **B: Bandwidth compressed LORAN**
  - LORAN (Long Range Navigation) is a terrestrial navigation system that uses low-frequency radio signals. While it can provide location information, it is not commonly used in amateur radio for real-time tracking of balloons. Additionally, bandwidth compression is not a standard term associated with LORAN in this context.

- **D: PACTOR III**
  - PACTOR III is a digital communication protocol used for email and data transfer over radio. While it is effective for sending data, it is not specifically designed for real-time tracking. PACTOR is more focused on reliable data transmission rather than location tracking.

### Summary

- **APRS** is the only option specifically designed for real-time tracking of moving objects, such as balloons, making it the correct answer. The other options serve different purposes in amateur radio and do not provide the same functionality.

### Useful Concepts

- **APRS Functionality**: 
  - APRS transmits location data using GPS coordinates, which can be displayed on mapping software or devices.
  
- **Packet Radio**: 
  - APRS operates using packet radio, which allows for efficient data transmission over amateur radio frequencies.

Understanding these distinctions will help you in the exam and in practical applications of amateur radio technology.