If there was an alternative to GPS that provided higher resolution tracking, what applications would there be for it in GIS? Note that this means higher resolution, but not necessarily higher accuracy. For instance, the absolute position (lat/long) would not be more accurate than GPS, but the relative movement during tracking could be within a few inches. This means you could get a very detailed track recording of a device's movement, allowing you to see small changes in position or elevation. If you were to carry this device while hiking a trail, you could see elevation changes with 1-5 inch resolution. I imagine this might be useful for GIS, but I am not familiar with the market. Any insight would be appreciated.
But doesn't such a thing already exist? Not as an alternative but as a complement technology. I'm thinking IMU's which, granted, track the orientation of the object, but sometimes the devices are combined (or accompanied) with an INS (Inertial navigation system). So: GPS + IMU can give you a 7 parameter position of an object, and you can (for a short period of time) replace GPS with an INS (whose issue is that accuracy is worsening with time/distance traveled). Unfortunately, to my knowledge, it is impossible to make such a bundle into a practical size at this point.
If you did, you could do all sorts of crazy stuff with that, for example, track a postal package to ensure it is handled properly, or always turned upwards as it should be (no radical position changes). Theft prevention. Limit object movement to a particular predefined area. Indoor navigation (where there is no proper GPS signal), cluster object monitoring (lots of objects that require good relative precision), for example overhead powerline wires,...
Whether or not there is a market for this. Hard to say, way more seemingly useless things turned out successful.
- Indoor navigation (as already mentioned), at least for a certain time/distance until the cumulative errors make it too unreliable.
- Urban use among tall buildings where your GPS fix may be intermittent, to provide the user a 'simulated' fix during GPS outages.
But particularly regarding the high precision aspect, not sure. People who need high precision usually also need high accuracy.
I agree with @U2ros answer in that a lot of this is already technologically possible. To a large extent phones now are getting smart enough to be able to do a lot of this if there were apps that could read/process the data efficiently and effectively.
As far as the market, I can't imagine there not being one. After all, marketing teams and such are already using various wi-fi triangulation and other in-door location determination techniques to identify a cell phone's location within a store to deliver location specific adds and coupons. So if you had an even more precise technique for this that could allow some existing business processes and customer information gathering processes to be automated even more, there would likely be numerous potential uses.