a10/a11

2026-04-20 22:10:24 +02:00
parent ca47910e4b
commit 571949421e
2 changed files with 13 additions and 0 deletions
--- a/a10.md
+++ b/a10.md
@@ -0,0 +1,6 @@
+# PNT Carrier Wave
+The UHF frequencies around 1.6 GHz were chosen for GPS and related applications
+because they provide a sensible tradeoff between
+- antenna size (bigger for lower frequencies),
+- ionospheric refraction (higher for lower frequencies),
+- absorption (higher for higher frequencies).