Research in Progress (RIP) https://rip.trb.org/ en-us Copyright © 2026. National Academy of Sciences. All rights reserved. http://blogs.law.harvard.edu/tech/rss tris-trb@nas.edu (Bill McLeod) tris-trb@nas.edu (Bill McLeod) Research in Progress (RIP) https://rip.trb.org/Images/PageHeader-wTitle-RIP.jpg https://rip.trb.org/ Ensuring PNT Resiience https://rip.trb.org/View/2676001 Mon, 02 Mar 2026 19:15:21 GMT https://rip.trb.org/View/2676001 PNT Protection through Interference Monitoring and Robust Backups to GNSS  https://rip.trb.org/View/2458990 Thu, 21 Nov 2024 17:26:16 GMT https://rip.trb.org/View/2458990 Railway Right of Way Monitoring and Early Warning System (RailMEWS) Based on Satellite and Aerial Imagery https://rip.trb.org/View/2353427 Mon, 25 Mar 2024 15:46:14 GMT https://rip.trb.org/View/2353427 Towards GNSS-less Navigation: Exploiting Terrestrial and LEO Satellite Signals of Opportunity https://rip.trb.org/View/2321512 Thu, 11 Jan 2024 16:07:04 GMT https://rip.trb.org/View/2321512 GNSS Interference: Situational Awareness and LEO Backup https://rip.trb.org/View/2301351 Mon, 04 Dec 2023 17:27:56 GMT https://rip.trb.org/View/2301351 Resilience and Validation of GNSS PNT Solutions https://rip.trb.org/View/1986928 Wed, 29 Jun 2022 14:41:35 GMT https://rip.trb.org/View/1986928 PNT with Signals of Opportunity and Real-World Jammed and Spoofed Environments https://rip.trb.org/View/1986929 Wed, 29 Jun 2022 14:36:53 GMT https://rip.trb.org/View/1986929 Test of COTS Satellite Communications Systems https://rip.trb.org/View/1367924 Thu, 03 Sep 2015 10:19:56 GMT https://rip.trb.org/View/1367924 Route and Site Characterization Using Multi-Spectral Satellite Imagery https://rip.trb.org/View/1339691 Thu, 01 Jan 2015 01:29:44 GMT https://rip.trb.org/View/1339691