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I don't think the GPS approach can work with ground stations - what GPS has going for it is line-of-sight to the satellites. Multipath would be a hell of an iss

I don't think the GPS approach can work with ground stations - what GPS has going for it is line-of-sight to the satellites. Multipath would be a hell of an issue in an urban environment. That said, here's a paper describing various positioning methods - http://emits.esa.int/emits-doc/1-5200-RD25-Signal-processing-techniques-network-aided-positioning.pdf http://emits.esa.int/emits-doc/1-5200-RD25-Signal-processing... EOTD looks rather interesting - https://en.wikipedia.org/wiki/E-OTD https://en.wikipedia.org/wiki/E-OTD

jf271 14y ago
WAAS is a combination of GPS and ground stations. It is accurate to about 6 feet. Widely used in aviation.
- modeless 14y ago
  The ground stations don't transmit to your device. WAAS still needs the satellite signals to work and so won't help indoor reception problems.
  - toomuchtodo 14y ago
    Correct. The ground reference stations multiplex their data to the WAAS satellite, which then pushes the data on WAAS-specific channels (hence, why your GPS receiver specifically needs to be built to support WAAS)