Future of GPS?
Like many of you I have been associated with GPS since 1991. However, I have never relied on it on a daily basis. I understand and appreciate it's capabilities.
Recently I have been reading more and more about the military moving away from its reliance, maintenance and support of the current GPS system. So, where does that leave the surveying community? Yes, I understand that the nation's transportation system relies on this system but will the nation turn to a new system and let GPS go the way of the dodo bird?
I don't get any sense the the government is doing anything but improving and investing in GPS. U.S. policy is pretty clear that GPS is considered a public utility and vital to the commercial/private sector, and the ~2 billion dollar budget allocation almost every year would seem to reflect this.
The military does seem to be investing additional resources in ALT-NAV capabilities. But that does not appear to be a replacement for GPS, just a backup if/when the military is operating in a GPS-denied environment. I'd be more surprised if they weren't looking into that sort of thing.
GPS.gov has a lot of resources on the subject. It's a great site, and I don't have enough time to do much more than skim the congressional reports, but I don't see anything to indicate that there is even a shred of support for ditching GPS entirely.
I can say that satellite navigation and positioning will probably be around for a long time and only improve. However history repeats itself. I believe that we are not far from astro observations for positioning in more of a real-time manner. I believe someone has on another post shown the NGS with Leica power point doing astro from basically a photo and such. In all honesty gps or satellite navigation is just humankind’s way if making its man made stars anyway. I in-vision one day I probably will not live to se it but being able to know where you are just by sun stars moon and who knows what else at high accuracy and precision. In a matter of a few seconds.
I believe that we are not far from astro observations for positioning in more of a real-time manner.
That will astonish me. Astro azimuth is pretty good. But astro latitude is so dependent on knowing the refraction that it is hard to get down to a small fraction of an arc minute, i.e. fraction of a mile.
@bill93 so true and time for longitude. Refraction has been and being studied a lot as of now. Lasers have opened the pandora box on that as they have become better and more understanding for long ranges at different heights above the earth. Some very smart young folks diving into that. At government levels.
@bill93 Do you have references to your statement that "astro latitude is so dependent on knowing the refraction that it is hard to get down to a small fraction of an arc minute, i.e. fraction of a mile".
Hope you have several references at least.
Here's one study that worked on a clear night, used a very good instrument, measured environmental conditions accurately, a geoid model, measured lots of stars against an accurate catalog, used GPS for timing, using 4 hours of field work, and came up with sigma on the order of 0.01", or roughly 1 ft.
I'd say that is hard.
@bill93 In your post you said a fraction of a minute (what do you mean by fraction of a minute?)
Now you show an article in Survey Review (of which I have) and show that they can get 0.01 seconds of arc.
Do you not know that 0.01 second is much smaller than your fraction of a minute? After all you said in your 1st post, fraction of a mile (whatever that is) and in your 2nd post 0.01", or roughly 1 ft.
Also you did not in either post say what type of instrument you are using. I guess a sexton for the mile?
Recently I have been reading more and more about the military moving away from its reliance, maintenance and support of the current GPS system.
I haven't heard a peep. Possibly since the general public, both inside and outside the US, has come to rely on it more and more there may be squawks about moving the funding out of defense spending?
Oops, A SPELLING ERROR by me above in my post. I said "sexton" and I meant SEXTANT. (or sex something)
I would have posted a correction long ago but our electrical storms here in Arizona kept me from doing so.