diff --git a/content/notes/09-location-sensors-3.md b/content/notes/09-location-sensors-3.md
index d4e61b0af..cf0491f29 100644
--- a/content/notes/09-location-sensors-3.md
+++ b/content/notes/09-location-sensors-3.md
@@ -7,6 +7,10 @@ tags:
 
 in lecture angles vs distances used to compute location
 
+gps distance
+nfc also distance
+cell tower both depending on configuration
+
 # Location Sensors - GPS (cont.)
 
 GPS - Receiver 
@@ -95,3 +99,8 @@ Real Time Kinematic (RTK)
 		- L1 receiver measures only L1 signal (19cm)
 > [!INFO] built on top of DGPS
 > assumes you use diff GPS with custom rover which is close to you 
+> not built into phone.
+> they cost a lot of money $1000 - $2000
+> you need a base station which is quite close to you
+
+
diff --git a/content/notes/10-orientation-sensors.md b/content/notes/10-orientation-sensors.md
index 1ec1ad183..2d6052ea2 100644
--- a/content/notes/10-orientation-sensors.md
+++ b/content/notes/10-orientation-sensors.md
@@ -5,6 +5,7 @@ tags:
 - info305
 ---
 
+> [!INFO] Location sensors dont know
 
 Accelerometers 
 - Measures proper acceleration (acceleration it experiences relative to freefall. gravity), felt by people or objects