Grid references?

[Parker Gabriel]

How do the numbers of grid references translate to degrees, minutes, and seconds of latitude and longitude?

There are many who want to know in order to understand just where a heading like "course two-eight-niner magnetic" will take anyone traveling from, say, Colorado Springs.

[Marion]

As the sainted Erica - the role model of all librarians -says,

This might help.
http://www.bbc.co.uk/scotland/education/sysm/landscapes/highlands_islands/mapskills/grid/index.shtml

If you need more information than that, try searching on Google.
If you mean the 'grid references' given in the TV shows, I have a sneaking suspicion that they wouldn't work . Although, I am ready to admit that there might be people who know more about it than me... (in fact there almost certainly are)
Anyone wanting to travel from 'Colorado Springs' to grid reference 'two-eight-niner magnetic' will have to use a road map like everyone else...

[Cerise]

It could be something as simple as a heading of 289 degrees from the direction of magnetic north. I have no idea where that would take you, though - I'll leave that to you
Of course it could be some supposed futuristic new method that doesn't currently exist - like Star Trek's 'star dates'. That way, no one can argue about the directions.
If in doubt, I would have a character say - "Set a course for..." then you don't have to worry about it at all.

[Clya Brown]

Impossible to tell unless you know where you're starting from - but if you do know where you're starting from it ought to be a matter of relatively straightforward geometry. You know where you are; you've got the bearing you want to take - say theta degrees; so the new X and Y coordinates will be something like {the original X coordinate} plus {the distance travelled times cos(theta)} and {the original Y coordinate} plus {the distance travelled times sin(theta)} respectively. You'll need to make sure the units of your grid references are compatible throughout, and that you make an allowance for the curvature of the Earth if you're going a long way. If you are going a long way then the calculations get quite nasty - but I can probably supply you with a reference within 24 hours if you're interested. But then, you'd never try to do something like that without a computer anyway - which is what almost certainly what most Spectrum operatives did unless they're very clever.

I'll throw one back to anyone with nothing better to do than watch their DVDs of the entire OCS series from beginning to end: how many times throughout the course of the series did the bearings of 124 and 142 magnetic get referred to? My recollection is that those were easily the most common ones ever heard, and possibly the only ones ever heard. Answers to be posted on this thread please, complete with the episodes in which they appeared. First person to get all of them wins a virtual coconut.

[chrisbishop]

Er... interesting theory, Doc. I'll make sure to download the proper program to install on my computer and will try to figure that out (Not!)

If I had time enough I would indeed sit down in front of the TV and watch the entire run of the show, but just for fun - not to take notes on the grid references (sorry!).

How do the numbers of grid references translate to degrees, minutes, and seconds of latitude and longitude?

My answer to the original question: these 'grid references' don't mean anything specific. More than certainly, they are but numbers given at random, just to make it look good on screen, because after all, it's only a kids' show, and if WE have no idea TODAY what the grid references could be, then it's fairly easy to figure out that when we first saw the show, we had no idea back then too, and kids today will not be much more wiser about that! Actually better than that: I do believe kids don't care that much about those grid references!

This is my straight answer.

But if I should care enough to give a 'save the plotline' answer: then perhaps it's all depend on where Cloudbase actually is, and each grid references would be different, according to the map that will appear on screen over the area the base is presently stationed over, the point of original reference always being Cloudbase.

[Mary Metcalfe]

How do the numbers of grid references translate to degrees, minutes, and seconds of latitude and longitude?

There are many who want to know in order to understand just where a heading like "course two-eight-niner magnetic" will take anyone traveling from, say, Colorado Springs.

My dear lad, why would you EVER need this information? Are you planning to take us all somewhere on a coaching holiday?

Mind you, I would much prefer going TO Colorado on holiday at this time of year. I fancy a bit of skiing...

As I am clearly NOT being serious here, I hope that you are equally not seriously interested in the calculation of grid references. Those numbers do not correspond to any official Ordnance Survey or miltary map references and are most likely just made up for the programme.

[Parker Gabriel]

Purpose being the fact that some people, who are NOT Anderphiles, may find the usage of grid references and their correlations to courses from triple-oh magnetic to three-five-niner magnetic a trifle difficult to understand. For myself, I rarely bother with grid references or concerns about courses from triple-oh magnetic to three-five-niner magnetic when writing Captain Scarlet fanfic.

Your figures may be different, so to phrase it.

[Marion]

People who are not Anderphiles, probably wouldn't care what the grid references were. It was a children's TV show - made to entertain - and I doubt anyone lost sleep over a few lines of dialogue.

[Clya Brown]

Marion - agreed. But then on the earlier point, it seems to me that people who are not Anderphiles are unlikely to be visiting this forum, period - so the existence or otherwise of a conversion program is unlikely to bother them very much one way or the other. This seems to be getting awfully similar to that incident when William Shatner hit the roof when a Trekkie asked him if he could remember the combination of the safe that he opened on one of the shows a couple of decades previously: playing with your own imaginary universe is fun - and it's why most of us are here - but when it becomes 51% of the world you live in then something's not quite right. I don't know how to convert between these various coordinate systems, and in a sense I'm actually rather glad I don't know - but I'll fish out the references to 3D geometry anyway: they're interesting enough in their own right if you're into that sort of thing.

[Clya Brown]

Okay... references as promised:

Firstly, a bit of background on relationships between spherical coordinate systems. After that, the fun starts...

A superb reference source for mathematical subjects generally is Wolfram Mathworld*, some of the links relevant to this particular thread being the ones relating to spherical geometry, spherical trigonometry and spherical triangles.

To get from A to B on the surface of a sphere, there are a few things you need to know about geodesics first, because the shortest distance between A and B lies along one of them. The formula for the distance between the points, given the longitude and latitude of each of them, is given on the page on great circles. The same page notes that adjusting these calculations for the slight flattening of the Earth at the poles is seriously difficult – see the page on oblate spheroids for details. Nevertheless it can apparently be programmed without too much difficulty: a JavaScript program that does just that can be found on the internet here, and there’s even an applet on the same page which does it for you. The original post however referred to the calculation of a destination point, given a starting point, bearing and distance. The code that does that can be found here, and again an applet is provided for you to try it out. So all you need now is the conversion formula to get from whatever system Spectrum uses into longitude and latitude in the first place… et voila! as Destiny might put it.

[* Anyone with teenage kids doing GCSE or A-level Maths ought to know about this site.]

[Marion]

ROFL
Thanks, Doc. I think
I'll stick to an A-Z Road map, or the instructions written on the back of an envelope... you know the sort of thing:
Pick up SPV B42 at Point A. Take main road A42 until you reach the Markham Arms. Turn left.
(No, not that left, the other left!)
Carry on until you can see the Hotspot Tower on the video screen.
Turn right towards the Biological Research Centre.
Take M21 slip road to Manchester, avoiding the low bridge at Culver. If you pass the Cafe de la Paix, you have gone too far.
Call Cloudbase if you get lost, and ask for Greenie....