Jump to content

wildlifewriter

+Premium Members
  • Posts

    694
  • Joined

  • Last visited

Posts posted by wildlifewriter

  1. I thought this new thread might help newcomers to the hobby (me, for instance) if people contribute their thoughts on good gear for geocaching. Obviously, similar equipment as for serious walking - proper clothing taken as read.

     

    Here's my own list, to start...

     

    Belt with pouches containing:

    GPS unit, mobile phone.

    SAK, Silva compass (lanyards, straps on everything)

    Spare batteries for the GPSr

    Spare batteries for the spare batteries.

    Current map in waterproof sleeve.

    Mini Maglite torch, sunglasses

     

    Pack with...

    Showerproof jacket, trousers.

    Dry socks, spare dry socks.

    More dry socks.

    Basic first aid kit, incl cream for nettle stings.

    Other maps, if applicable.

    Gardening gloves.

    Trade goods, extra pencils, in loc/loc box.

    Tissues, or bog roll.

    Insect repellent wipes.

    Various disreputable hats.

    Even more batteries.

     

    Things I always forget, or leave in the car...

     

    The cache notes.

    My wallet.

  2. In general, it would be nice if people would give us an idea of how their GPSr was performing when they placed a cache.

     

    Just a thought (and somewhat OT) but if everyone had decimetre-accurate equipment for placing and finding caches - the whole thing: WADGPS, phase differentials, etc, - would it not ruin the hobby completely...?

  3. Still would be nice to know if Memory Map (MM) or GPS was the more accurate conversion for my area i.e. Scotland

    My 2d worth...

     

    Working this out from the OSTN02 transformation, I get the following:-

     

    From: N 55 58.305 W 04 17.496

    Convert to Deg.Min/Sec: N 55 58 18.3 W 04 17 29.76

    Convert to OSGB(36): 57081.2 , 77788.9

     

    You pays yer money and you takes yer choice :P

     

    Incidentally, I also tried to see what Garmin's MapSource software would do with these figures. It gave the same result (exactly) as your Garmin GPSr. (No surprises there, then.)

     

    So... why the discrepancy? At a guess, perhaps GPS software designers were worried (quite rightly) that their wee machines did not have enough memory/processor power to use the horribly cumbersome OS tables and equations. They probably employ a simpler (but slightly less accurate) formula which can be implemented at some reasonable speed.

     

    You and I would be the first to complain if our Garmin receivers paused every now and again, with a screen display which read...

     

    ----------------------

    FiGURING OUT

    WHERE WE ARE

     

    (Please wait...)

     

    ----------------------

     

    :mad:

     

    Paul

  4. current data is being sent with an “ignore bit” set so whether its set on or off on the GPSr wont matter as most GPSr manufacturers check this “ignore bit” and disregard the signal

     

    There's more to it than that:

     

    To understand what's happening at the moment, let's anthropomorphise for a moment and imagine what a GPSr does, when it sees one of the SBAS-type satellites...

     

    (These comments generally refer to a Garmin consumer unit, and an eTrex type in particular.)

     

    1)I can download the almanac (orbital information) for this satellite. So far, so good.

     

    2)I now know which satellite it is, and what it's supposed to be doing. THIS one is supposed to be transmitting SBAS information, for me to use in positional corrections.

     

    3)None of the information appears to be any use. I am not going to waste one of my receiver channels listening to this garbage. Ignore it. OR...

     

    (4)The information appears useful, but it doesn't apply to the area where I am, now. It might be useful some other time, but ignore it for now. OR...

     

    (5)The information is valid, and applies to HERE. However, the satellite is also transmitting the “DO NOT USE” indicator. Maybe it's faulty, or under maintenance. Because I'm a Garmin GPSr, I know not to apply the corrections, 'cos they might be wrong. However, I'll remember THIS satellite for future reference.

     

    (6)OK. Now.. lets listen to see if there are any other SBAS satellites which I can use.... (back to (1))

     

    Paul

  5. As you are aware, there are already quite a few caches in the greater mourne area, all of which comes under the SAC and ASSI umbrella....

    I am only aware of one existing cache which is inside the designated area: GCGB5Z.

     

    I cannot see how placing a cache on the summit is going to drastically increase the numbers of visitors to the site.(etc)

    I'm sure the E&H Service will agree with you, when you write to them.

     

    You ARE writing to them, aren't you...? ;)

     

    Paul

  6. Barnabus is intending to place one, but I can't say whether it will be there in time. I'll e-mail him to see what the plan is (if any).

    He (or me, or any of us) will have to clear it with the local Environment and Heritage Service, first.

     

    On checking, Donard is within a SAC and ASSI designated area. Full details, here... NBN Gateway

     

    and.. ;) getting premission might take some time, because the civil servants here are all on strike.

  7. (etc) ...Is this just conversion discrepencies? but which one is more accurate ?

     

    Both are accurate but (to oversimplify) the Earth is round - unless you are in Arkansas - whereas maps are flat. (Except when you let the kids fold them.)

     

    To represent a curved surface on a flat map, needs a positional distortion known as the "map projection". There are many ways of doing this, according to the use being made of the map, the area covered by it, and so on.

     

    A whole lot more about this, here... GIS mapping

     

    Every map -digital or paper - that you might have, should if it's any good, specify the "datum". That's the setting you were altering on your GPS'r. If the datum selected is different from that under which the map was drawn, you will see the 'discrepancies' you mention. However, this is not a fault in the GPSr - it's only doing what you told it to do.

     

    Now... I assume that the MM maps you mention are OSGB ones. And you would think that the correct applicable datum for these would be "OSGB", right?

     

    Wrong.

     

    The MM maps have been adapted for use in GPS applications, and seem to use WGS84, so that's what they use when displaying a Lat/Long entry.

     

    Hth,

     

    Paul

  8. The label claims they are waterproof and air tight and they're guaranteed for 5 years. (They don't, however, mention geocaching)

     

    Got some today (in Belfast, so they ARE available all over). Seem to be quite good quality and, with 'locking tabs', easier to open and close than some other designs. The small ones would make better mini-caches than the traditional jamjar.

     

    I can report that the pastic did not discolour or deteriorate, even during the enormous period of time I spent queuing for Woolie's glacial checkout....

    :ph34r:

     

    Paul

  9. Okay, so we all know where Britain's highest Geocache is (Ben Nevis summit), but I was wondering where the lowest is?

     

    Dunno, but the lowest (land) point in GB is in the area S and/or E of Peterborough. Flag Fen, or Holme Fen possible - they're both several metres b.s.l.

     

    Any cache around the Bedford Levels has got to be a candidate... :ph34r:

     

    Paul

  10. I think someone else may have plans for a cache on Slieve Donard

     

    No problem - if it gets done... :ph34r:

     

    850m climb? - piffling (he says from comfort of armchair, sipping whisky)...

     

    Yes. Having now passed the big five-0, that's how I climb most of 'em, as well... WLW

  11. I think that a cache on Slieve Donard may appear before much longer

     

    <sigh>.... I suppose we could do one, if you really REALLY want one up there. It's 850m* - and you'll be doing it from as near sea level as makes no difference.

     

    At least co-ord accuracy won't be a problem: Donard summit trig is the "fundamental station" for the whole Irish mapping datum. So...

     

    N 54 10' 48".262

    W 05 55' 11".898

     

    ...give or take a centimetre <_<

     

    Hth

     

    Paul

     

    [* or 849m, depending on datum. YMMV.]

  12. SSSI's are a particular instance where we try and apply a RULE whereby we have to be absolutely sure permission has been properly obtained. (snip)

    Indeed, but permission itself should be the only one consideration. Thought should be given to possible disturbance when a proposed cache is close to a protected area. This is especially important where the area is a shoreline, estuary, or other significant wetland; these can be very sensitive at certain times of the year.

     

    In the UK, many such places are designated under the international Ramsar Covention, and they can be extensive. For example: here in Northern Ireland, the entire foreshore of Strangford Lough is a designated area and thus legally protected.

     

    There is a useful hyperlinked map service here CIESIN map viewer

     

    Hope this helps.

×
×
  • Create New...