Sub-refraction is on page 35, and Super-refraction appears on pages 35 and 117 — Page 393, Lesson 406

This is the index of the book — the map of everything we're about to cover. I want to walk you through the entries here, because they tell you exactly what topics matter in radio navigation, and they give you the page numbers so you can find them later. Let's start with the propagation topics. Sub-refraction is on page 35, and Super-refraction appears on pages 35 and 117. These are atmospheric bending effects on radio waves — sub-refraction bends them less than normal, super-refraction bends them more. We'll get into the details when we reach those pages. Super High Frequency (SHF) is on page 8. That's the frequency band from 3 to 30 gigahertz. Surface Wave is on page 21 — that's a radio wave that travels along the Earth's surface. Now the radar entries. Surveillance Radar Approach (SRA) is on page 184 — that's a ground-controlled approach procedure. Surveillance Radars are on page 190. Swept Gain is on page 217 — that's a technique to reduce sea clutter returns. TAR on page 199 stands for Terminal Area Surveillance Radar. TGT Alert on page 220 is a target alert function. Tilt Control on page 215 is the radar antenna tilt adjustment. Theoretical Maximum Range is on page 187. Thunderstorms appear on pages 98 and 219 — they're significant radar targets. Now the satellite navigation entries. SV Clock Error is on pages 309 and 317 — that's the satellite vehicle clock error. SV Clock Time is on page 309. SV Position is on page 309 — the satellite's position. Time to First Fix is on page 313 — how long the receiver takes to get a position fix. Time Dilution of Precision (TDOP) is on page 318 — that's a measure of how clock errors affect position accuracy. The navigation systems: TACAN on page 246 — that's Tactical Air Navigation. TCAS on page 285 — Traffic Collision Avoidance System. TEST VOR (VOT) on page 115 — that's a ground test facility for VOR receivers. TO/FROM on pages 118 and 121 — that's the VOR indicator showing whether you're flying toward or away from the station. The multiplexing entries: TDM on page 174 stands for Time Division Multiplexing, also called Time Multiplexing on the same page. Time Referenced Scanning Beam is also on page 174 — that's the MLS scanning technique. TMA on page 200 is Terminal Control Area. And finally, The Ionosphere is on page 24 — that's the atmospheric layer that affects radio wave propagation. That's the T-section of the index. It's a good preview of the ground we'll cover — propagation, radar, satellite navigation, and the systems that tie them together.