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.
I got to Pickle III before I started anthropomorphizing. Then some poor chap got carried off by one of the balloons. The other guy held fast. You might want to check on him.
Not us, we did FW dev. Not every SW engineer is a web dev working in cloud, even on HN. Also in web dev many run and test things locally so working with good machines helps.
Also, the equipment you get shows you how little a company values its engineers and how much it values its management. If they insist on giving you the cheapest bottom of the barrel laptop and monitors they can find, they probably won't pay you competitively as well. A lesson I found the hard way.
Yea, to back up the point some more. I work on a completely desktop enterprise solution. So there is no offloading the work from my machine either. Our test suite even on moderately fast hardware still takes about 10 minutes to run the full suite parallelized.
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 believe this might be the correct answer. The signal from a GPS satellite is incredibly weak (way below the thermal noise of a typical amplifier) and can only be detected by correlating it with the satellite's unique gold code. In addition, the satellites move pretty fast which leads to sizeable Doppler shifts of their carrier frequencies (tens of kHz). This has to be taken into account in the signal demodulation.
Classical GPS receivers use the almanac (and a reasonably accurate local clock) to determine which satellites are probably in view, and with which Doppler shifts. I would not be surprised if modern GPS chips had enough compute power to simply correlate the received signal with all gold codes and at all reasonable Doppler shifts. The almanac is then no longer necessary.
The almanac is still needed, it has the orbital positions and those change over days. I think current GPS receivers can receive from lots if not all satellites at once. Different satellites are transmitting different parts of almanac. The receiver downloads the almanac in parallel.
Modern GNSS receivers with modern multi-band antennas can track hundreds of satellites simultaneously across all the various GNSS systems including GPS, GLONASS, GALILEO, etc....
This is how they build RTK surveying equipment, and they can have their own RTK reference point that uses statistical averaging over time to get accuracy down to the centimeter range or below, and then rebroadcast that to the local RTK rover nodes. There are multiple correction systems available that you can subscribe to, some of which can transmit their corrections via 4G/LTE/5G or other radio band communications, so that you don't need your own RTK reference for your rover units.
For good RTK equipment, you can easily pay $40k or more, but if you look around you can find some equipment that costs less than $1000. My current favorite is the SparkFun GPS RTK Express Kit, although you need a pair of them if you want to do your own RTK reference point and you don't subscribe to one of the various other correction systems.
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.
TBH having live real time position error transmitted to live in motion "local area" moving bodies (drones | aircraft | vehicles | missiles) is useful for live dynamic tasks (shooting the enemy) .. but not especially useful for surveying per se.
I spent decades in high precision geophysical surveying using ground stations (fixed GPS recievers) and craft (aircraft | helicopters | etc) and it was common practice to collect data and post process ... merge airframe GPS data and ground station corrections in conjunction with other numerical corrections .. at the end of day.
For various forms of survey you really want to not transmit to|from your airframer "live" in any case - for EM | magnetic survey that's just another source of noise best dealt with by having everything not required switch off.
I concede the value for regular ground site survey tasks .. there's no downside to transmitting and applying corrections in real time - but it's not strictly required and for some forms of surveying it's preferable to record raw unaltered data and apply fixes later with the option of rolling back | examining the raw | etc.
I can see the value of recording the raw data at the time and then applying the corrections after the fact. I'm sure there are applications for that mode of operations.
But for the ground surveying and ground control RTK equipment I've been looking at, you do want to apply those corrections in real time. For example, if you're controlling a tractor that is pulling a lot of heavy equipment through a field of crops, and you want to make sure you line up correctly on the product being farmed (e.g., corn), you want to make sure that your tractor goes exactly where you want it to go, and in real time.
In my mind, that's what Real Time Kinetics is all about.
Heh - I came back to correct myself, I completely forgot about ground surveyors hammering in pins | monuments - they want the real time corrections as they go for that task.
But yeah, real time control of moving vehicles is exactly where you want transmitted corrections - it originated with military requirements to correct in real time as interceptors close in on targets and today (like yourself?) I use it in the agricultural domain for tractors and drones.
It occurs to me that if you're just passively looking at the data that is collected, then collecting that data and correcting it afterwards may well be the best approach.
But if you're taking actions that might result in changing the thing or the space you're surveying (like putting in markers, or controlling heavy equipment, or directing the application of military force), then that's where you will most likely want to have those real time corrections.
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.
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.
The best answwr today is that it's complicated, very complicated.
Eg: as laid out in [1] which deserves a thorough and close reading.
There's little evidence that cannabis induces (causes) schizophreniform psychoses in people who aren't already at risk of developing such conditions already.
( Eg: A study modelling trends in the incidence of psychoses in Australia did not find clear evidence of any increase in incidence following steep increases in cannabis use during the 1980s
And that's from a thirty year look back in a country of 20+ million with extremely comprehensive public health records and cheap accessable professional docters and access to medication )
There's ample evidence that cannabis and schizophreniform psychoses go hand in hand in a self reinforcing spiral that leads to no good end.
( Numerous examples cited with the paper [1] ).
Like most drugs it's one that's best avoided until full maturity and fully avoided if there are any signs of onset psychoses otherwise relatively harmless in moderation and with an eye to actual effect.
[1] Cannabis use and the risk of developing a psychotic disorder World Psychiatry (2008)
Recreational drugs alter mental perception, otherwise no one would take them. It's a bit disingenuous to argue that psychotic drugs won't have a relationship to the causes of mental illness.
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.
In many ways, sites/tools like sourceforge and github made it much easier to publish and obtain open source software, leading to much more software being created and shared. I'm suggesting that "too much content" isn't a problem, and leads to good things.
