I was at a beachhouse north of Boston and I thought someone fell out of bed or dropped something really heavy upstairs. It was loud and the whole house shook. All of us were scouring the internet for like an hour, finding absolutely nothing "official" or any mention of it on news sites- just tons of subreddits and other social media blowing up all over the Northeast wondering what the heck it was.
I sketched something in the first sky and then our started putting up blobs with a single word like "sun" and "banana." I have no idea what's going on.
The value of RTK is partially that they are stationary and can average out noise over time to get an accurate position estimate, but mostly that they're sending you their live signal measurements so you can cancel out biases common to receivers which are geographically co-located.
The almanac is not needed. The ephemeris is basically just almanac orbital data plus extra terms to make it accurate enough for meter-level positioning or better. I'm not sure what you mean by saying the orbital parameters change over days. Ephemerides are updated every ~2 hours to maintain precise positioning.
Discarding assisted GPS where GPS data messages are obtained through about channel such as cellular or Wifi...
Almanac gives coarse satellite position information (and some other stuff), good enough to know which ones are probably visible and therefore prioritize signal acquisition attempts which used to be very very costly in terms of signal processing. That's the message that takes up 12.5 minutes to piece together. Nowadays you can just brute force all possible satellite signals and there's no need to wait around for the almanac information. Each satellite signal broadcasts precise satellite location information (ephemeris), which takes maybe 30 seconds to get a few frames I believe. So that's basically the bottleneck for a modern chipset which starts with zero information and relies solely on the GPS signals to navigate.
I find that hard to believe. You could probably correlate many mental facility intake patients with those that ate yogurt for breakfast. This is ignorant fear mongering.
You can take an amplitude-vs-time representation of a signal and via a Fourier Transform instead represent the same information as a sum of weighted complex exponentials in the frequency domain. It works mathematically, sure- but does that mean that- physically, at the core of existence- every RF, acoustic, seismic, or financial data ripple is actually a bunch of sines and cosines which are getting summed together to create the real phenomena?
One is a human, the other is some AI hoovering up everything I say an adding it to their database which can be used in every other instance of Teams in the world. I'd say that's a meaningful difference.
I was making an America Goulash recipe once, and thought I'd give the beyond burger or whatever a try; it wasn't patties but was jut a pound of ground "beef." It didn't brown or cook up correctly; it smelled awful and perfumed the whole house. I made the recipe and it was straight up gross. We threw it all away.