31–40 of 122 posts
Earlier quoted context omitted.
There are two limits: 60000ft and 1000 knots. Some manufacturers use "AND" between them, others use "OR"[1]. So you can have faster drones if you manage to stay below 60000 ft. [1] https://ukhas.org.uk/guides:gps_modules
Which is weird, because something traveling at 1000kts at 100ft seems scarier than something doing 1000kts at 60000ft.
For a drone to be affected by GPS speed limits it would have to be a hypersonic drone.
There are two limits: 60000ft and 1000 knots. Some manufacturers use "AND" between them, others use "OR"[1]. So you can have faster drones if you manage to stay below 60000 ft. [1] https://ukhas.org.uk/guides:gps_modules
Do any of these systems offer a way to cryptographically prove that a signal was received at a specific place and time?
However, GPS signals are essentially just the location of the satellite with a time stamp. There's nothing to prevent the signed signal from being re-broadcast a short time later to mess with location data. The Russians have (allegedly) been doing this in the Black, Baltic, and Berants seas the past few years.
Earlier quoted context omitted.
I find a bit of humor in imagining NASA rocket launches and atmospheric test vehicles being viewed, in some contexts, as a munition.
Well, both the Atlas and Soyuz (currently used by NASA and Roskosmos) were developed primarily for the U.S. and Soviet militaries as ICBM vehicles, the Space Race was something of a PR operation. After all, you don't really need to have an explosive payload: just dropping a heavy enough missile can be devastating.
Since kinetic energy increases with the square of velocity, if you can create a payload that can travel at hypersonic speeds (like a tungsten rod) without burning up then the amount of kinetic energy is in the tens of millions of joules. That's enough to destroy any single target, but doesn't have nearly the same destructive power as a nuke, which releases trillions of joules of energy.
Thoughts on how this sort of thing, even though CoreSemi is Singapore/Japan-based, might fall afoul of US ITAR restrictions? As a scientist, open hardware is the best. I'm just not sure whether or not CoreSemi might have put its foot in something bigger than they know.
Affordable differential GPS would be a nice application... it just requires a fast way of synchronization between two devices (CW in the ISM band would probably work, for example).
RTK gps is better and quite affordable now. Look it up, you can use two receivers costing maybe $15 each for it.
Earlier quoted context omitted.
The speed limit in the US is 1000mph, else it’s a munition. I believe the US used to make their GPS slightly inaccurate, but this was done on the satellite side.
I find a bit of humor in imagining NASA rocket launches and atmospheric test vehicles being viewed, in some contexts, as a munition.
A good example is shock absorbers designed for vehicles heavier than 30 tons. It has all kinds of civilian uses in heavy machinery, but since that's a key tech for armored vehicles, they are also on the munitions list. The same applies for rocket and jet engines above certain parameters, all kinds of space imaging technology, etc, etc.
Earlier quoted context omitted.
The speed limit in the US is 1000mph, else it’s a munition. I believe the US used to make their GPS slightly inaccurate, but this was done on the satellite side.
I find a bit of humor in imagining NASA rocket launches and atmospheric test vehicles being viewed, in some contexts, as a munition.
It’s a bit political than technical that in American English guided rocket weapons are always called “missiles“. Same reason as J in NASA JPL stands for _jet_ though they don’t normally do turbine jets.
So calling non-military rockets as munitions could be, I think, potentially more straightforward.
Earlier quoted context omitted.
Well, both the Atlas and Soyuz (currently used by NASA and Roskosmos) were developed primarily for the U.S. and Soviet militaries as ICBM vehicles, the Space Race was something of a PR operation. After all, you don't really need to have an explosive payload: just dropping a heavy enough missile can be devastating.
Are you referring to Kinetic Bombardment?[0] Since kinetic energy increases with the square of velocity, if you can create a payload that can travel at hypersonic speeds (like a tungsten rod) without burning up then the amount of kinetic energy is in the tens of millions of joules. That's enough to destroy any single target, but doesn't have nearly the same destructive power as a nuke, which releases trillions of jou…
but that’s enough to destroy any single target! Like some bunkers.