*Question E1D01:
[97.3] What is the definition of telemetry?*  

*Correct Answer is  A: One-way transmission of measurements at a distance from the measuring instrument*  

### AI Response: (may contain errors)  

Telemetry is a crucial concept in amateur radio and other fields, and understanding its definition is important for the Extra Class exam.

### Correct Answer Explanation:
- **A: One-way transmission of measurements at a distance from the measuring instrument**  
  This is the correct definition of telemetry. It refers to the process of collecting data from a remote or inaccessible location and transmitting it back to a receiving station. This is typically done without any feedback or two-way communication, which is a key characteristic of telemetry.

### Incorrect Answer Explanations:
- **B: Two-way transmissions in excess of 1000 feet**  
  This choice is incorrect because telemetry is specifically a one-way transmission. The distance mentioned (1000 feet) is irrelevant to the definition of telemetry, which does not involve two-way communication.

- **C: Two-way transmissions of data**  
  This option is incorrect as it describes a different type of communication. Telemetry is not about two-way data exchange; it is focused on sending data from a measuring instrument to a remote location without receiving any data back.

- **D: One-way transmission that initiates, modifies, or terminates the functions of a device at a distance**  
  While this describes a form of remote control or command transmission, it does not fit the definition of telemetry. Telemetry is strictly about the transmission of measurements, not about controlling or modifying devices.

### Summary:
- Telemetry is a one-way communication method used to send measurements from a remote location.
- It is important to distinguish telemetry from other forms of communication, such as two-way data transmissions or remote control operations.

Understanding these distinctions will help you answer related questions on the exam effectively.