In article <s7nsk2$kg4$1@dont-email.me>, Tweed <usenet.tweed@gmail.com>
scribeth thus
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <s7m7k0$6e5$1@dont-email.me>, at 17:13:51 on Fri, 14 May
>> 2021, tim... <timsnews99@gmail.com> remarked:
>>>
>>>
>>> "MB" <MB@nospam.net> wrote in message news:s7iv87$995$2@dont-email.me...
>>>> On 13/05/2021 08:51, Roland Perry wrote:
>>
>>>>>> And before that (when it was primarily used commercially for shipping
>>>>>> (and air??)) it was a US military system with intentional degradation
>>>>>> of the signal for non-military uses. Accuracy was never better than
>>>>>> about 100 metres - adequate for basic navigation at sea.
>>
>>>>> The selective availability was scrapped in 2000, which was a couple of
>>>>> years before the car I mentioned was built.
>>
>>>> Wasn't there pressure from politicians?
>>>
>>> It was engineered out by the development of Differential GPS
>>
>> For some very specialised civilian applications (I think a friend I know
>> with a yacht subscribed to one such scheme). It wouldn't have helped
>> in-car satnavs at all.
>
>Oh yes it would. The differential signal was encoded onto the Classic FM
>signal, with a DGPS receiver fitted to each transmitter. (The correction
>degrades the further you get from the fixed DGPS reference receiver, so
>fitting it to FM transmitters that had a reasonably constrained coverage
>worked well) It was encrypted and they were hoping for users to pay for the
>service. Had selective availability continued it would have been fairly
>likely that it would have become a feature in cars. However the removal of
>SA killed the project stone dead.
>
>In practical tests it brought in car positional accuracy to slightly better
>that what we see currently with the civilian non selective availability
>signal.
>
>
>
Most every east Anglian farming baron now has high accuracy GPS fitted
on their tractors so much so that they can and sometimes are steered by
them. Look that the lines in the second advert millimetre controlled!

The farmer we have hereabouts isn't leaning up against a gate chewing on
a bit of grass saying "Oooh arr" and ger offa moi land!, nope he's
sitting back in his office with a bank of PC screens seeing monitoring
and controlling what's going on at his now precision controlled farm!...

http://www.precisiondecisions.co.uk/

https://vantage-ag.uk/solutions-precision-agriculture/

--
Tony Sayer

Man is least himself when he talks in his own person.

Give him a keyboard, and he will reveal himself.

On 29/05/2021 16:38, tony sayer wrote:
> In article <s7nsk2$kg4$1@dont-email.me>, Tweed <usenet.tweed@gmail.com>
> scribeth thus
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <s7m7k0$6e5$1@dont-email.me>, at 17:13:51 on Fri, 14 May
>>> 2021, tim... <timsnews99@gmail.com> remarked:
>>>>
>>>>
>>>> "MB" <MB@nospam.net> wrote in message news:s7iv87$995$2@dont-email.me...
>>>>> On 13/05/2021 08:51, Roland Perry wrote:
>>>
>>>>>>> And before that (when it was primarily used commercially for shipping
>>>>>>> (and air??)) it was a US military system with intentional degradation
>>>>>>> of the signal for non-military uses. Accuracy was never better than
>>>>>>> about 100 metres - adequate for basic navigation at sea.
>>>
>>>>>> The selective availability was scrapped in 2000, which was a couple of
>>>>>> years before the car I mentioned was built.
>>>
>>>>> Wasn't there pressure from politicians?
>>>>
>>>> It was engineered out by the development of Differential GPS
>>>
>>> For some very specialised civilian applications (I think a friend I know
>>> with a yacht subscribed to one such scheme). It wouldn't have helped
>>> in-car satnavs at all.
>>
>> Oh yes it would. The differential signal was encoded onto the Classic FM
>> signal, with a DGPS receiver fitted to each transmitter. (The correction
>> degrades the further you get from the fixed DGPS reference receiver, so
>> fitting it to FM transmitters that had a reasonably constrained coverage
>> worked well) It was encrypted and they were hoping for users to pay for the
>> service. Had selective availability continued it would have been fairly
>> likely that it would have become a feature in cars. However the removal of
>> SA killed the project stone dead.
>>
>> In practical tests it brought in car positional accuracy to slightly better
>> that what we see currently with the civilian non selective availability
>> signal.
>>
>>
>>
> Most every east Anglian farming baron now has high accuracy GPS fitted
> on their tractors so much so that they can and sometimes are steered by
> them. Look that the lines in the second advert millimetre controlled!
>
> The farmer we have hereabouts isn't leaning up against a gate chewing on
> a bit of grass saying "Oooh arr" and ger offa moi land!, nope he's
> sitting back in his office with a bank of PC screens seeing monitoring
> and controlling what's going on at his now precision controlled farm!...
>
> http://www.precisiondecisions.co.uk/
>
> https://vantage-ag.uk/solutions-precision-agriculture/
>
>

And then texting Ger offa moi land!

--
Graeme Wall
This account not read.

tony sayer <tony@bancom.co.uk> wrote:
> In article <s7nsk2$kg4$1@dont-email.me>, Tweed <usenet.tweed@gmail.com>
> scribeth thus
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <s7m7k0$6e5$1@dont-email.me>, at 17:13:51 on Fri, 14 May
>>> 2021, tim... <timsnews99@gmail.com> remarked:
>>>>
>>>>
>>>> "MB" <MB@nospam.net> wrote in message news:s7iv87$995$2@dont-email.me...
>>>>> On 13/05/2021 08:51, Roland Perry wrote:
>>>
>>>>>>> And before that (when it was primarily used commercially for shipping
>>>>>>> (and air??)) it was a US military system with intentional degradation
>>>>>>> of the signal for non-military uses. Accuracy was never better than
>>>>>>> about 100 metres - adequate for basic navigation at sea.
>>>
>>>>>> The selective availability was scrapped in 2000, which was a couple of
>>>>>> years before the car I mentioned was built.
>>>
>>>>> Wasn't there pressure from politicians?
>>>>
>>>> It was engineered out by the development of Differential GPS
>>>
>>> For some very specialised civilian applications (I think a friend I know
>>> with a yacht subscribed to one such scheme). It wouldn't have helped
>>> in-car satnavs at all.
>>
>> Oh yes it would. The differential signal was encoded onto the Classic FM
>> signal, with a DGPS receiver fitted to each transmitter. (The correction
>> degrades the further you get from the fixed DGPS reference receiver, so
>> fitting it to FM transmitters that had a reasonably constrained coverage
>> worked well) It was encrypted and they were hoping for users to pay for the
>> service. Had selective availability continued it would have been fairly
>> likely that it would have become a feature in cars. However the removal of
>> SA killed the project stone dead.
>>
>> In practical tests it brought in car positional accuracy to slightly better
>> that what we see currently with the civilian non selective availability
>> signal.
>>
>>
>>
> Most every east Anglian farming baron now has high accuracy GPS fitted
> on their tractors so much so that they can and sometimes are steered by
> them. Look that the lines in the second advert millimetre controlled!
>
> The farmer we have hereabouts isn't leaning up against a gate chewing on
> a bit of grass saying "Oooh arr" and ger offa moi land!, nope he's
> sitting back in his office with a bank of PC screens seeing monitoring
> and controlling what's going on at his now precision controlled farm!...
>
> http://www.precisiondecisions.co.uk/
>
> https://vantage-ag.uk/solutions-precision-agriculture/
>
>

How Jeremy Clarkson fell in love with farming — and cooked up a plan to
save the countryside

<https://www.thetimes.co.uk/article/35663596-b95b-11eb-8a71-bc144e6a30f1?shareToken=62d639f2c1c7fcbf228c4bd500866dc4>