Author Topic: GPS after Brexit  (Read 15467 times)

Re: GPS after Brexit
« Reply #100 on: 25 August, 2020, 05:13:00 pm »
If civilian GPS were turned off now, the only people getting their Nandos from Uber Eats would be the ones who used their what3words address, and we don't want that to happen.

If I could hack my what3words address to pizza here now I'd never go hungry.   ;D

Or surrounded by fat people in cars , angry that you aren’t offering free pizza.

Davef

GPS after Brexit
« Reply #101 on: 25 August, 2020, 06:03:09 pm »
I was sloppy in my wording.

I was trying to say ...

A single point in 3 dimensional space and time (obtained through measurement of transmission times from at least 4 satellites of GPS or one of the other GNSSs or obtained otherwise) is insufficient to define a line segment that is needed as the basis of navigation.


A point in space time, are we now time travelling as well? Giles fetch the Tardis ;D

So you’re saying if given a single coordinate , a once off , and no update if you move, then you can’t navigate? Bit like if you were given a 5m x 5m square of map, with a red dot saying you are here, that did not update as you moved?

Clearly you can still navigate by what you can see.  But you’re right, the single coordinate won’t necessarily help (much), on its own, just as the tiny fixed fragment of map won’t help you navigate.

But that’s a very long way from not being to able to navigate solely with a gps and your eyes.

If you think about it, you’ll also realise there are methods of navigation that are not point to point but based on terrain and / or valley systems. So not dependent on having a line segment as the basis.
I wasn’t suggesting time travel. It is necessary to calculate the time which is why you need a minimum of 4 satellites for a decent position (3 would be sufficient for a point in 3-space). The reason for this is that the time needs to be incredibly accurate, far better than you can obtain from a normal clock because you are working out your position based on the speed of light, even a millionth of second is 300m.

Re: GPS after Brexit
« Reply #102 on: 25 August, 2020, 06:13:40 pm »
I was sloppy in my wording.

I was trying to say ...

A single point in 3 dimensional space and time (obtained through measurement of transmission times from at least 4 satellites of GPS or one of the other GNSSs or obtained otherwise) is insufficient to define a line segment that is needed as the basis of navigation.


A point in space time, are we now time travelling as well? Giles fetch the Tardis ;D

So you’re saying if given a single coordinate , a once off , and no update if you move, then you can’t navigate? Bit like if you were given a 5m x 5m square of map, with a red dot saying you are here, that did not update as you moved?

Clearly you can still navigate by what you can see.  But you’re right, the single coordinate won’t necessarily help (much), on its own, just as the tiny fixed fragment of map won’t help you navigate.

But that’s a very long way from not being to able to navigate solely with a gps and your eyes.

If you think about it, you’ll also realise there are methods of navigation that are not point to point but based on terrain and / or valley systems. So not dependent on having a line segment as the basis.
I wasn’t suggesting time travel. It is necessary to calculate the time which is why you need a minimum of 4 satellites for a decent position (3 would be sufficient for a point in 3-space). The reason for this is that the time needs to be incredibly accurate, far better than you can obtain from a normal clock because you are working out your position based on the speed of light, even a millionth of second is 300m.
Indeed time is used in the technicalities of calculating position due to the nature of how it works. But the location derived , the point coordinates, has no time dimension. It is not a point in space and time. Just a coordinate for a location on Earth.

Davef

GPS after Brexit
« Reply #103 on: 25 August, 2020, 06:43:24 pm »
I was sloppy in my wording.

I was trying to say ...

A single point in 3 dimensional space and time (obtained through measurement of transmission times from at least 4 satellites of GPS or one of the other GNSSs or obtained otherwise) is insufficient to define a line segment that is needed as the basis of navigation.


A point in space time, are we now time travelling as well? Giles fetch the Tardis ;D

So you’re saying if given a single coordinate , a once off , and no update if you move, then you can’t navigate? Bit like if you were given a 5m x 5m square of map, with a red dot saying you are here, that did not update as you moved?

Clearly you can still navigate by what you can see.  But you’re right, the single coordinate won’t necessarily help (much), on its own, just as the tiny fixed fragment of map won’t help you navigate.

But that’s a very long way from not being to able to navigate solely with a gps and your eyes.

If you think about it, you’ll also realise there are methods of navigation that are not point to point but based on terrain and / or valley systems. So not dependent on having a line segment as the basis.
I wasn’t suggesting time travel. It is necessary to calculate the time which is why you need a minimum of 4 satellites for a decent position (3 would be sufficient for a point in 3-space). The reason for this is that the time needs to be incredibly accurate, far better than you can obtain from a normal clock because you are working out your position based on the speed of light, even a millionth of second is 300m.
Indeed time is used in the technicalities of calculating position due to the nature of how it works. But the location derived , the point coordinates, has no time dimension. It is not a point in space and time. Just a coordinate for a location on Earth.

The result is 3D spatial coordinates and time. For the purposes of navigation the time may or may not be relevant. For other uses of GPS the time may be of more importance than the position.

Edit: though the time could be useful for sanity checking. If the results come back as “Buckingham in 2036”, something is probably awry.

Re: GPS after Brexit
« Reply #104 on: 25 August, 2020, 07:39:33 pm »
For other uses of GPS the time may be of more importance than the position.
One example: we keep time using atomic clocks and there are lots of atomic clocks around the world. The way we determine the accuracy of any given atomic clock is to compare it to lots of other atomic clocks, and one way to do that is to compare to GPS time https://www.bipm.org/en/bipm/tai/time-transfer/

frankly frankie

  • I kid you not
    • Fuchsiaphile
Re: GPS after Brexit
« Reply #105 on: 25 August, 2020, 11:32:57 pm »
There is some evidence that mammals including humans have an ability to detect the earths magnetic field like migratory birds. If so it is very subconscious.

I dunno about subconscious.  It's not difficult to detect (within 10 degrees or so) where the sun is in the sky, even on overcast days.  Is this awareness 'subconscious'?  I'd call it 'natural'.  Match that to time of day - well some people (I speak as one) have an innate sense of time passing and time-of-day without reference to clocks, watches, phones etc.  So I would say I always know where north is, give or take, during daylight, because I always know where the sun is and I always know whether it's morning, evening, noon or night (and many gradations between).  And yes I suppose the total computation is at the subconscious level.
when you're dead you're done, so let the good times roll

Davef

Re: GPS after Brexit
« Reply #106 on: 26 August, 2020, 06:53:31 am »
There is some evidence that mammals including humans have an ability to detect the earths magnetic field like migratory birds. If so it is very subconscious.

I dunno about subconscious.  It's not difficult to detect (within 10 degrees or so) where the sun is in the sky, even on overcast days.  Is this awareness 'subconscious'?  I'd call it 'natural'.  Match that to time of day - well some people (I speak as one) have an innate sense of time passing and time-of-day without reference to clocks, watches, phones etc.  So I would say I always know where north is, give or take, during daylight, because I always know where the sun is and I always know whether it's morning, evening, noon or night (and many gradations between).  And yes I suppose the total computation is at the subconscious level.
Birds, insects and some vertebrates are detecting the magnetic field directly - it is for example disrupted by power lines. Generally it is thought humans do not have this ability but there have been some experiments suggesting it could still be present at a very low level. These experiments excluded other cues by being conducted inside with no windows. You mentioned your innate sense of time -  one of the proteins involved in regulating the human body clock is sensitive to magnetic fields and is thought to be involved in how homing pigeons ‘see’ magnetic field lines.

Ben T

Re: GPS after Brexit
« Reply #107 on: 26 August, 2020, 09:09:26 am »
My (female) dogs always do a little twirly dance before they poo. I've never thought to check their orientation.

I'll make a spreadsheet and report back.

Apparently cows always piss north.

Davef

Re: GPS after Brexit
« Reply #108 on: 26 August, 2020, 09:41:30 am »
My (female) dogs always do a little twirly dance before they poo. I've never thought to check their orientation.

I'll make a spreadsheet and report back.

Apparently cows always piss north.
I think the theory of the benefit to herd animals is that if you are all randomly aligned and you sprint off when a predator arrives you crash into each other.

Unfortunately attaching a cow, even a smallish one, to the handlebars as a navigation device could be challenging.

The other week, whilst cycling, I narrowly avoided being pissed on by a sheep.

Re: GPS after Brexit
« Reply #109 on: 26 August, 2020, 11:32:26 am »


My (female) dogs always do a little twirly dance before they poo. I've never thought to check their orientation.

I'll make a spreadsheet and report back.

Apparently cows always piss north.

Unfortunately attaching a cow, even a smallish one, to the handlebars as a navigation device could be challenging.


Plus all the water needed for a regular bearing check.

Sent from my SM-G930F using Tapatalk


Re: GPS after Brexit
« Reply #110 on: 26 August, 2020, 02:06:42 pm »
I was sloppy in my wording.

I was trying to say ...

A single point in 3 dimensional space and time (obtained through measurement of transmission times from at least 4 satellites of GPS or one of the other GNSSs or obtained otherwise) is insufficient to define a line segment that is needed as the basis of navigation.


A point in space time, are we now time travelling as well? Giles fetch the Tardis ;D

So you’re saying if given a single coordinate , a once off , and no update if you move, then you can’t navigate? Bit like if you were given a 5m x 5m square of map, with a red dot saying you are here, that did not update as you moved?

Clearly you can still navigate by what you can see.  But you’re right, the single coordinate won’t necessarily help (much), on its own, just as the tiny fixed fragment of map won’t help you navigate.

But that’s a very long way from not being to able to navigate solely with a gps and your eyes.

If you think about it, you’ll also realise there are methods of navigation that are not point to point but based on terrain and / or valley systems. So not dependent on having a line segment as the basis.
I wasn’t suggesting time travel. It is necessary to calculate the time which is why you need a minimum of 4 satellites for a decent position (3 would be sufficient for a point in 3-space). The reason for this is that the time needs to be incredibly accurate, far better than you can obtain from a normal clock because you are working out your position based on the speed of light, even a millionth of second is 300m.
Indeed time is used in the technicalities of calculating position due to the nature of how it works. But the location derived , the point coordinates, has no time dimension. It is not a point in space and time. Just a coordinate for a location on Earth.

The result is 3D spatial coordinates and time. For the purposes of navigation the time may or may not be relevant. For other uses of GPS the time may be of more importance than the position.

Edit: though the time could be useful for sanity checking. If the results come back as “Buckingham in 2036”, something is probably awry.

The result being you can use just a gps and that data to navigate.

Davef

Re: GPS after Brexit
« Reply #111 on: 26 August, 2020, 02:12:15 pm »
I was sloppy in my wording.

I was trying to say ...

A single point in 3 dimensional space and time (obtained through measurement of transmission times from at least 4 satellites of GPS or one of the other GNSSs or obtained otherwise) is insufficient to define a line segment that is needed as the basis of navigation.


A point in space time, are we now time travelling as well? Giles fetch the Tardis ;D

So you’re saying if given a single coordinate , a once off , and no update if you move, then you can’t navigate? Bit like if you were given a 5m x 5m square of map, with a red dot saying you are here, that did not update as you moved?

Clearly you can still navigate by what you can see.  But you’re right, the single coordinate won’t necessarily help (much), on its own, just as the tiny fixed fragment of map won’t help you navigate.

But that’s a very long way from not being to able to navigate solely with a gps and your eyes.

If you think about it, you’ll also realise there are methods of navigation that are not point to point but based on terrain and / or valley systems. So not dependent on having a line segment as the basis.
I wasn’t suggesting time travel. It is necessary to calculate the time which is why you need a minimum of 4 satellites for a decent position (3 would be sufficient for a point in 3-space). The reason for this is that the time needs to be incredibly accurate, far better than you can obtain from a normal clock because you are working out your position based on the speed of light, even a millionth of second is 300m.
Indeed time is used in the technicalities of calculating position due to the nature of how it works. But the location derived , the point coordinates, has no time dimension. It is not a point in space and time. Just a coordinate for a location on Earth.

The result is 3D spatial coordinates and time. For the purposes of navigation the time may or may not be relevant. For other uses of GPS the time may be of more importance than the position.

Edit: though the time could be useful for sanity checking. If the results come back as “Buckingham in 2036”, something is probably awry.

The result being you can use just a gps and that data to navigate.
Absolutely. I completely agree a gps navigation device is all you need to navigate. I have never thought otherwise, even though my poor wording might have led you, but not others, to believe so, but I think I have explained that on several occasions.

Re: GPS after Brexit
« Reply #112 on: 26 August, 2020, 05:26:11 pm »
I was sloppy in my wording.

I was trying to say ...

A single point in 3 dimensional space and time (obtained through measurement of transmission times from at least 4 satellites of GPS or one of the other GNSSs or obtained otherwise) is insufficient to define a line segment that is needed as the basis of navigation.


A point in space time, are we now time travelling as well? Giles fetch the Tardis ;D

So you’re saying if given a single coordinate , a once off , and no update if you move, then you can’t navigate? Bit like if you were given a 5m x 5m square of map, with a red dot saying you are here, that did not update as you moved?

Clearly you can still navigate by what you can see.  But you’re right, the single coordinate won’t necessarily help (much), on its own, just as the tiny fixed fragment of map won’t help you navigate.

But that’s a very long way from not being to able to navigate solely with a gps and your eyes.

If you think about it, you’ll also realise there are methods of navigation that are not point to point but based on terrain and / or valley systems. So not dependent on having a line segment as the basis.
I wasn’t suggesting time travel. It is necessary to calculate the time which is why you need a minimum of 4 satellites for a decent position (3 would be sufficient for a point in 3-space). The reason for this is that the time needs to be incredibly accurate, far better than you can obtain from a normal clock because you are working out your position based on the speed of light, even a millionth of second is 300m.
Indeed time is used in the technicalities of calculating position due to the nature of how it works. But the location derived , the point coordinates, has no time dimension. It is not a point in space and time. Just a coordinate for a location on Earth.

The result is 3D spatial coordinates and time. For the purposes of navigation the time may or may not be relevant. For other uses of GPS the time may be of more importance than the position.

Edit: though the time could be useful for sanity checking. If the results come back as “Buckingham in 2036”, something is probably awry.

The result being you can use just a gps and that data to navigate.
Absolutely. I completely agree a gps navigation device is all you need to navigate. I have never thought otherwise, even though my poor wording might have led you, but not others, to believe so, but I think I have explained that on several occasions.

Oh come on, you can tell from the replies from others such as Greenbank that your words were clearly interpreted that way. It just everybody else got bored with your changing responses. :P

Davef

Re: GPS after Brexit
« Reply #113 on: 26 August, 2020, 05:33:18 pm »
I was sloppy in my wording.

I was trying to say ...

A single point in 3 dimensional space and time (obtained through measurement of transmission times from at least 4 satellites of GPS or one of the other GNSSs or obtained otherwise) is insufficient to define a line segment that is needed as the basis of navigation.


A point in space time, are we now time travelling as well? Giles fetch the Tardis ;D

So you’re saying if given a single coordinate , a once off , and no update if you move, then you can’t navigate? Bit like if you were given a 5m x 5m square of map, with a red dot saying you are here, that did not update as you moved?

Clearly you can still navigate by what you can see.  But you’re right, the single coordinate won’t necessarily help (much), on its own, just as the tiny fixed fragment of map won’t help you navigate.

But that’s a very long way from not being to able to navigate solely with a gps and your eyes.

If you think about it, you’ll also realise there are methods of navigation that are not point to point but based on terrain and / or valley systems. So not dependent on having a line segment as the basis.
I wasn’t suggesting time travel. It is necessary to calculate the time which is why you need a minimum of 4 satellites for a decent position (3 would be sufficient for a point in 3-space). The reason for this is that the time needs to be incredibly accurate, far better than you can obtain from a normal clock because you are working out your position based on the speed of light, even a millionth of second is 300m.
Indeed time is used in the technicalities of calculating position due to the nature of how it works. But the location derived , the point coordinates, has no time dimension. It is not a point in space and time. Just a coordinate for a location on Earth.

The result is 3D spatial coordinates and time. For the purposes of navigation the time may or may not be relevant. For other uses of GPS the time may be of more importance than the position.

Edit: though the time could be useful for sanity checking. If the results come back as “Buckingham in 2036”, something is probably awry.

The result being you can use just a gps and that data to navigate.
Absolutely. I completely agree a gps navigation device is all you need to navigate. I have never thought otherwise, even though my poor wording might have led you, but not others, to believe so, but I think I have explained that on several occasions.

Oh come on, you can tell from the replies from others such as Greenbank that your words were clearly interpreted that way. It just everybody else got bored with your changing responses. :P
I am really bored with it too. Clearly I misunderstood what I was trying to say.

Re: GPS after Brexit
« Reply #114 on: 21 September, 2020, 03:21:58 pm »
More of our money gone to spivs as the UK finally realises OneWeb won’t work. Now the UK plans to ask if it can get back on the Galileo project.

https://www.theneweuropean.co.uk/top-stories/uk-goverment-could-rejoin-eu-s-galileo-system-1-6848108