*Question E3C09:
What type of data is reported by amateur radio propagation reporting networks?*  

*Correct Answer is  D: Digital-mode and CW signals*  

### AI Response: (may contain errors)  

Amateur radio propagation reporting networks, such as WSPRnet and PSK Reporter, collect and report data on the reception of digital-mode and CW (Continuous Wave) signals. This data helps operators understand current propagation conditions by showing which signals are being received and where.

### Explanation:

1. **Correct Answer: Digital-mode and CW signals**
   - These networks focus on collecting data about the reception of digital-mode and CW signals. This information is used to analyze and predict radio wave propagation conditions, helping operators determine the effectiveness of their transmissions and the current state of the ionosphere.

2. **Why the Other Choices are Incorrect:**
   - **A: Solar flux**
     - Solar flux is a measure of solar activity and is not directly reported by amateur radio propagation networks. Instead, it is measured by scientific organizations and used to predict propagation conditions.
   - **B: Electric field intensity**
     - Electric field intensity refers to the strength of an electric field at a point in space. It is not typically reported by amateur radio propagation networks, which focus on signal reception data.
   - **C: Magnetic declination**
     - Magnetic declination is the angle between magnetic north and true north. It is not related to radio signal propagation and is not reported by these networks.

### Useful Information:

- **Propagation Reporting Networks:**
  - These networks provide real-time data on signal paths and reception quality, which can be used to assess propagation conditions.
  - They are particularly useful for understanding how different frequencies and modes perform under varying solar and atmospheric conditions.

Understanding the type of data reported by these networks helps amateur radio operators optimize their communication strategies and better predict when and where their signals will be most effective.