From 34955edc62aa310b184bb1a00b62558217ecc89f Mon Sep 17 00:00:00 2001 From: Jet Hughes Date: Tue, 28 Mar 2023 12:34:38 +1300 Subject: [PATCH] vault backup: 2023-03-28 12:34:38 --- content/notes/09-location-sensors-3.md | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/content/notes/09-location-sensors-3.md b/content/notes/09-location-sensors-3.md index 8a20ce00c..c0ea081a6 100644 --- a/content/notes/09-location-sensors-3.md +++ b/content/notes/09-location-sensors-3.md @@ -32,6 +32,8 @@ Urban Canyon ![Urban canyon](https://i.imgur.com/1aKMSLg.png) > [!INFO] buildings block some satellites > reflected signals take more time to arrive and disrupt accuracy +> also happens with lower building that are closer together +> happens also with trees GPS - Problems @@ -45,8 +47,10 @@ GPS - Problems - “Very large errors are uncommon and rarely exceed 30m” - Long startup time ( 30s - 12.5min needed for sending almanac) - Several proposed improvements: AGPS, DGPS, RTKGPS - -> [!INFO] ^Depends on many parameters +> [!INFO] ^Depends on many parameters +> bad weather also affects travel time hence accuracy +> long start up time. almanac (satellite position and future positions) is a large amount of data that each device needs to recieve +> with data/wifi can download almanac from phone provider # Location Sensors - AGPS, DGPS, RTK GPS @@ -61,8 +65,9 @@ A(ssisted) GPS - Higher precision (with WiFi Positioning & cell-site multilateration) - Disadvantages: - Requires Internet connection - ![A(ssisted) GPS](https://i.imgur.com/u7iLeWG.png) +> [!INFO] most relevant to us. used in mobile phones. trad gps uses only satellite. AGPS used that and network information +> also incorporates wifi and cell location D(ifferential) GPS - Enhancement to GPS to increase location accuracy and integrity