Pilots and radar operators are the primary users of refractive data, and as it is with almost all environmental products, we must put the data in a format that is easy to read and under-stand. Always include the actual figure for the N-gradient and give the zone in which the gradient is occurring. For example, 18 N -units per 1,000 feet from the surface is 2,500 feet.

Some of the products that we pass onto the user, other than those that are computer generated, are the N-curve graph and the refractive index worksheet. Since the worksheet contains computational data and user data, you should highlight the user information.

It is now time to apply the information that you have received. Read Appendix IV and complete the exercise in the Appendix. Write down any questions you may have on the material, and go over your questions with your training petty officer, immediate supervisor, or chief.