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199609 [2016/06/17 11:23] – [Basic Rule in Treatment (continued from August 'first aid notes')] vievems | 199609 [2016/06/17 12:29] (current) – [GPS Units] vievems | ||
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My name was mentioned in the May news in connection with GPS (Global Positioning System) units. I have gathered some information on these devices which I think will be of interest to members who have heard of these but have not had the time to look more deeply. I should mention that I have never used one of these devices so some of the following is based upon experiences reported by others. | My name was mentioned in the May news in connection with GPS (Global Positioning System) units. I have gathered some information on these devices which I think will be of interest to members who have heard of these but have not had the time to look more deeply. I should mention that I have never used one of these devices so some of the following is based upon experiences reported by others. | ||
- | The units operate by receiving radio wave signals from satellites. The frequencies used are such that they are significantly affected by moisture. Some units are not useable in forests due to the attenuation of the signals by moisture in the leaves. It may be necessary to find a 'clearing in order to get a positive reading. Similarly, rain Or falling snow can effect the ability of the units to operate correctly. | + | The units operate by receiving radio wave signals from satellites. The frequencies used are such that they are significantly affected by moisture. Some units are not useable in forests due to the attenuation of the signals by moisture in the leaves. It may be necessary to find a clearing in order to get a positive reading. Similarly, rain or falling snow can effect the ability of the units to operate correctly. |
- | Other objects may attenuate, reflect or otherwise impair the signals. | + | |
- | position reading if you are in a valley, gully, hut or similar situation.. | + | Other objects may attenuate, reflect or otherwise impair the signals. |
- | The current practical accuracy of GPS for bushwalking under good conditions is about 100 'metres horizontally, | + | |
- | system which is roughly similar to GPS). You can buy receivers for these systems but they are much more expensive and/or currently impractical for our bushwalking use. For various reasons this will probably remain the case for the next couple of years. | + | The current practical accuracy of GPS for bushwalking under good conditions is about 100 metres horizontally, |
- | To give you position, the GPS needs to gather information from several satellites (at least three to give a position without height | + | |
- | information). Better accuracy is obtained if more satellites are used (under ideal conditions more than 12 are possible, but 5 or 6 are probably more typical in good locations). Most of the cheaper GPS units process the signals one satellite at a time. Some units are capable of processing several signals simultaneously. The advantage of this approach is that it enables the unit to give good results on poorer signals. For the bushwalker, this means that these units are much more likely to be useable in forests, valleys, etc. | + | To give you position, the GPS needs to gather information from several satellites (at least three to give a position without height information). Better accuracy is obtained if more satellites are used (under ideal conditions more than 12 are possible, but 5 or 6 are probably more typical in good locations). Most of the cheaper GPS units process the signals one satellite at a time. Some units are capable of processing several signals simultaneously. The advantage of this approach is that it enables the unit to give good results on poorer signals. For the bushwalker, this means that these units are much more likely to be useable in forests, valleys, etc. |
GPS units get data from the satellites at a low data rate (50 bits per second). It normally takes 12.5 minutes for a satellite to transmit its whole message. To avoid having to wait this time, GPS units store information even when they are turned off. This way, it can take as little as 15 seconds or so for a GPS unit to give you a reading when you turn it on. It will take longer, perhaps several minutes, if the information it contains is not sufficiently accurate or is stale. | GPS units get data from the satellites at a low data rate (50 bits per second). It normally takes 12.5 minutes for a satellite to transmit its whole message. To avoid having to wait this time, GPS units store information even when they are turned off. This way, it can take as little as 15 seconds or so for a GPS unit to give you a reading when you turn it on. It will take longer, perhaps several minutes, if the information it contains is not sufficiently accurate or is stale. | ||
+ | |||
You can leave the GPS unit switched on and get a continuous reading of your position as you walk along. However, a new set of batteries will be drained in less than 10 hours (perhaps as little as 2 hours by some GPS units when used this way. | You can leave the GPS unit switched on and get a continuous reading of your position as you walk along. However, a new set of batteries will be drained in less than 10 hours (perhaps as little as 2 hours by some GPS units when used this way. | ||
- | The GPS unit keeps very accurate time, which can be used by the UPS receiver to give you a very accurate clock. However this information may not be accurately displayed while the GPS unit is performing position calculations. | + | |
+ | The GPS unit keeps very accurate time, which can be used by the UPS receiver to give you a very accurate clock. However, this information may not be accurately displayed while the GPS unit is performing position calculations. | ||
The price of GPS units is becoming more attractive. It is claimed that it is currently possible to buy a small | The price of GPS units is becoming more attractive. It is claimed that it is currently possible to buy a small | ||
hand held unit (250 g with batteries) for $250 Australian. | hand held unit (250 g with batteries) for $250 Australian. | ||
+ | |||
The usefulness of GPS units in Australian bushwalking is not well established. Anecdotal evidence ranges from somewhat useful to almost useless. Considering the relatively low price of some units, it might be worthwhile for the Club to consider purchasing a unit for our navigators to evaluate. | The usefulness of GPS units in Australian bushwalking is not well established. Anecdotal evidence ranges from somewhat useful to almost useless. Considering the relatively low price of some units, it might be worthwhile for the Club to consider purchasing a unit for our navigators to evaluate. | ||
+ | |||
If you want to use a GPS unit as a navigational aid when bushwalking then you will want to use the unit in conjunction with maps. To avoid some pitfalls when purchasing or setting up a GPS unit, you should be aware of one or two basic facts: | If you want to use a GPS unit as a navigational aid when bushwalking then you will want to use the unit in conjunction with maps. To avoid some pitfalls when purchasing or setting up a GPS unit, you should be aware of one or two basic facts: | ||
- | 1. The earth is not spherical. The mapping authorities model the earth with an object called a spheroid. Different spheroids are used for different regions of the earth. The spheroid, in combination with other information gives a datum which is used when making maps. a consequence is that the latitude and longitude of a given place depends upon which datum is used. In Australia the maps we use for bushwalking are based on the Australian Geodetic Datum 1996 (AGD66) or the later version (AGD84). | + | |
- | 2. With the datum, you get to latitude and longitude. For bushwalking we seldom bother with latitude and longitude. Instead we use the more useful map grid (which is based on the datum).A GPS unit which does not give your position in map grid coordinates will be of limited use to you. | + | 1. The earth is not spherical. The mapping authorities model the earth with an object called a spheroid. Different spheroids are used for different regions of the earth. The spheroid, in combination with other information gives a datum which is used when making maps. A consequence is that the latitude and longitude of a given place depends upon which datum is used. In Australia the maps we use for bushwalking are based on the Australian Geodetic Datum 1996 (AGD66) or the later version (AGD84). |
- | If you purchase a GPS unit you should make sure that it supports either A0D66 or AGD84 datum (the difference between these wont matter to you, look for the words Australian, datum and 1966 or 1984). If your unit doesn' | + | |
- | -abOirt," | + | 2. With the datum, you get to latitude and longitude. For bushwalking we seldom bother with latitude and longitude. Instead we use the more useful map grid (which is based on the datum). |
- | liiiih | + | |
- | will Want the unit to be able to give' | + | If you purchase a GPS unit you should make sure that it supports either A0D66 or AGD84 datum (the difference between these wont matter to you, look for the words Australian, datum and 1966 or 1984). If your unit doesn' |
- | . | + | In addition |
- | you Australian map grid coordinates but the manual for your GPS unit probably wont mention the Australian map grid, however it will hopefully mention UTM (Universal Transverse Mercator) which is the projecti6ii | + | |
- | Once you have purchased your GPS unit and set it up, you can probably safely forget all of this, at least for the next few years (however; see below.). | + | Once you have purchased your GPS unit and set it up, you can probably safely forget all of this, at least for the next few years (however, see below). |
- | Australia is currently shifting to a new mapping datum called GDA94. On the good side, this is for our purposes identical to the WGS84 now will be able to give horizontal position with the new datum. On the bad side, the new datum gives positions which differ horizontally from the old by about 200 metres (a different datum is used for height). This means that when maps are produced using the new datum you will find that all the features on them will have shifted by this 200 metre amount: the target date for implementation is the year 2000, but in fact the new datum will be phase4 | + | |
+ | Australia is currently shifting to a new mapping datum called GDA94. On the good side, this is for our purposes identical to the WGS84 now will be able to give horizontal position with the new datum. | ||
There you have it. GPS Units are available, at prices which aren't outrageous. They are potentially useful as a bushwalking aid to navigation, but not as a substitute to navigate with a map and compass. Care needs to be taken before making a purchase, for example one unit with one of the best reputations for use in bushwalkng-type conditions (because it can process several signals simultaneously) lacks the UTM transformation and hence is difficult to use with maps. | There you have it. GPS Units are available, at prices which aren't outrageous. They are potentially useful as a bushwalking aid to navigation, but not as a substitute to navigate with a map and compass. Care needs to be taken before making a purchase, for example one unit with one of the best reputations for use in bushwalkng-type conditions (because it can process several signals simultaneously) lacks the UTM transformation and hence is difficult to use with maps. | ||
- | On a related topic,: AUSLIGhas | + | |
- | elevation detail to speak of at finer scales ie contours, mountains, etc" and is therefor | + | On a related topic, |
From the June 1996 issue of the Melbourne Bushwalking Club newsletter. | From the June 1996 issue of the Melbourne Bushwalking Club newsletter. | ||
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As many of you know my reason for coming to Cairns is to gain experience as a tour guide and this I am certainly doing. My initiation has been pretty torrid, almost daunting but at the same time very rewarding. I am currently working for only one company, "The Adventure Company" | As many of you know my reason for coming to Cairns is to gain experience as a tour guide and this I am certainly doing. My initiation has been pretty torrid, almost daunting but at the same time very rewarding. I am currently working for only one company, "The Adventure Company" | ||
- | The Adventure Company runs sea kayak trips off the coast to some beautiful coral islands, canoe trips down the Mulgrave River, mountain | + | The Adventure Company runs sea kayak trips off the coast to some beautiful coral islands, canoe trips down the Mulgrave River, mountain |
fire. I get fed so well all the time that it's a wonder I haven' | fire. I get fed so well all the time that it's a wonder I haven' | ||
- | Cairns is growing city, there is building work going on everywhere. I understand there are more hotel rooms per capita then anywhere else in the world and I can believe it! There are masses of tourists, many of them from overseas, and most of them on a whirlwind visit. For instance many of those who come through "The Adventure | + | Cairns is a growing city, there is building work going on everywhere. I understand there are more hotel rooms per capita then anywhere else in the world and I can believe it! There are masses of tourists, many of them from overseas, and most of them on a whirlwind visit. For instance many of those who come through "The Adventure |
Company" | Company" | ||
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Finally the big temptation is to go north up The Cape to "The Tip". I am currently looking for an opportunity to do just that so if you are interested please let me know and I'm sure I can work something out. | Finally the big temptation is to go north up The Cape to "The Tip". I am currently looking for an opportunity to do just that so if you are interested please let me know and I'm sure I can work something out. | ||
+ | |||
As you may have guessed I am missing you guys a whole lot so if you feel like coming up for a visit you will be very welcome. Let me know before you book anything as I can arrange some excellent deals from this end (except airfares). | As you may have guessed I am missing you guys a whole lot so if you feel like coming up for a visit you will be very welcome. Let me know before you book anything as I can arrange some excellent deals from this end (except airfares). | ||
- | My address in Cairns is: | + | My address in Cairns is: 286 Gatton Street, Westcourt 4870. My phone number is 015 066 870. |
- | 286 Gatton Street, Westcourt 4870. My phone number is 015 066 870. | + | |
Good walking. | Good walking. | ||
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There was no general business so the meeting proceeded to the announcements and closed at 2133. | There was no general business so the meeting proceeded to the announcements and closed at 2133. | ||
- | ==== Notices ==== | + | ===== Notices |
=== Some Enchanted Evening - Thursday October 17 === | === Some Enchanted Evening - Thursday October 17 === | ||
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- | ==== A Snippet From Column 8 ==== | + | === A Snippet From Column 8 === |
observer Barbara Bruce | observer Barbara Bruce | ||
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===== First Aid (continued from August 'first aid notes' | ===== First Aid (continued from August 'first aid notes' | ||
- | **2. Basic Rule in Treatment** | + | === 2. Basic Rule in Treatment |
First aid courses teach **DRABC** as the basic way of treatment. This check list may only take a couple of seconds but should be followed on all occasions. | First aid courses teach **DRABC** as the basic way of treatment. This check list may only take a couple of seconds but should be followed on all occasions. | ||
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EAR and cardiac massage are not covered in these notes, see Additional Information below. | EAR and cardiac massage are not covered in these notes, see Additional Information below. | ||
- | === Signs & Symptoms === | + | __Signs |
Signs are the clues which the first aider observes from the patient; eg colour, temperature, | Signs are the clues which the first aider observes from the patient; eg colour, temperature, | ||
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Symptoms are giddiness, dizziness, headache. | Symptoms are giddiness, dizziness, headache. | ||
- | 3 Hypothermia Exposure (too cold) | + | === 3. Hypothermia Exposure (too cold) === |
Occurs when the body core cools too much, from prolonged immersion in cold water, damp clothes on a cold, windy and rainy day (NB chill factor), coupled with physical exhaustion and hunger. | Occurs when the body core cools too much, from prolonged immersion in cold water, damp clothes on a cold, windy and rainy day (NB chill factor), coupled with physical exhaustion and hunger. | ||
- | Signs & Symptoms | + | |
- | Treatment | + | __Signs |
- | mild cases wrap the casualty up and give warm, sweet drink (NB not too hot to scald, and make sure the casualty can have sugar). Give chocolate to eat. For severe cases cuddle up together in a sleeping bag with plenty of skin to skin contact. Don't be shy or embarrassed, | + | |
- | 4 Hyperthermia (Heat Exhaustion - too hot). | + | Irrational thinking, slurred speech, stumbling, consciousness. |
- | Included here are severe sunburn, heat exhaustion and heat stroke. For sunburn see bums below. Heat stress is an elevated body temperature and occurs when the body can no longer control its temperature by sweating. It can occur on bushwalks when the temperature is high, the humidity is high, wearing too much clothing, strenuous walking such as climbing. Heat stroke is extreme heat exhaustion. | + | |
- | Signs & Symptoms | + | __Treatment__ |
- | dizziness, feeling hot, exhausted but restless, muscular cramps, fast and shallow breathing, skin pale and clammy, pulse rapid and weak. | + | |
- | Treatment | + | Do not give alcohol to drink. Do not expose to excessive external heat. Immediately do what you can to prevent further heat loss and then get to a sheltered spot. For mild cases wrap the casualty up and give warm, sweet drink (NB not too hot to scald, and make sure the casualty can have sugar). Give chocolate to eat. For severe cases cuddle up together in a sleeping bag with plenty of skin to skin contact. Don't be shy or embarrassed, |
- | or cooler place-in the shade. | + | |
- | P 14 | + | === 4. Hyperthermia (Heat Exhaustion - too hot) === |
- | 5 Shock | + | |
- | The body's response to an inadequate supply of oxygen to the tissues. The body reacts to shock by directing blood away from the less important tissues to the vital organs (brain, heart and | + | Included here are severe sunburn, heat exhaustion and heat stroke. For sunburn, see burs below. Heat stress is an elevated body temperature and occurs when the body can no longer control its temperature by sweating. It can occur on bushwalks when the temperature is high, the humidity is high, wearing too much clothing, strenuous walking such as climbing. Heat stroke is extreme heat exhaustion. |
- | kidneys). Shock may result from severe bleeding, severe burns, loss of fluids by vomiting or dehydration or an accident such as a fracture. Shock, called an anaphylactic shock may also result from severe allergic reaction to insect bite. | + | |
- | Signs & Symptoms | + | __Signs |
- | giddy, may lose consciousness, | + | |
- | Treatment | + | Headache, dizziness, feeling hot, exhausted but restless, muscular cramps, fast and shallow breathing, skin pale and clammy, pulse rapid and weak. |
- | 6 Sprains & Fractures | + | |
- | For treatment sprains and fractures are the same, however the severity of the injury may be very different. If in doubt treat a sprain or suspected fracture as a fracture. Sprains and fractures may also cause shock. For bushwalking, | + | __Treatment__ |
- | Signs & Symptoms | + | |
- | an unusual angle, bone fracture protruding from the skin, inability to carry the full weight on the | + | Remove casualty to a cool or cooler place - in the shade. |
- | leg, shock, swelling of the joint, inability to move the fingers, wrist, toes, foot or great pain in doing so. Secondary injuries may be concussion, grazing, cuts and bruises from a fall. | + | |
- | Treatment | + | === 5. Shock === |
- | 7 Snake Bite | + | |
- | Assume the snake is venomous. Identify the snake if possible but do not waste time trying to catch it and maybe getting bitten yourself The majority of bites are to the lower leg with the rest to the hand or forearm. Bites elsewhere are difficult to treat, but the first aid is the same. The current (1996) theory and treatment for snake bite is as follows; because the snake venom travels along the lymph system to the heart, treatment is to apply pressure to the affected part of the body in order to slow down the rate of travel of the venom. At a slow rate the body can rid itself of the venom, | + | The body's response to an inadequate supply of oxygen to the tissues. The body reacts to shock by directing blood away from the less important tissues to the vital organs (brain, heart and kidneys). Shock may result from severe bleeding, severe burns, loss of fluids by vomiting or dehydration or an accident such as a fracture. Shock, called an anaphylactic shock, may also result from severe allergic reaction to insect bite. |
- | Signs & Symptoms | + | |
- | the bite site, and one or more of the following: disturbed vision, nausea and vomiting, headache, drowsiness and fainting, sweating, pain in the abdomen, difficulty in breathing, diarrhoea, shock. | + | __Signs |
- | Treatment | + | |
+ | Feels weak, faint, giddy, may lose consciousness, | ||
+ | |||
+ | __Treatment__ | ||
+ | |||
+ | If unconscious apply DRABC, turn onto the casualty' | ||
+ | |||
+ | === 6. Sprains & Fractures | ||
+ | |||
+ | For treatment sprains and fractures are the same, however, the severity of the injury may be very different. If in doubt treat a sprain or suspected fracture as a fracture. Sprains and fractures may also cause shock. For bushwalking, | ||
+ | |||
+ | __Signs | ||
+ | |||
+ | Leg, foot or arm at an unusual angle, bone fracture protruding from the skin, inability to carry the full weight on the leg, shock, swelling of the joint, inability to move the fingers, wrist, toes, foot or great pain in doing so. Secondary injuries may be concussion, grazing, cuts and bruises from a fall. | ||
+ | |||
+ | __Treatment__ | ||
+ | |||
+ | First DRABC, then carefully remove the casualty to an area free of danger and where treatment can be given. Surface wounds, cuts etc. may need to be attended to before treatment of the fracture. Immobilise the limb with a splint using wide bandages to spread the pressure and padding on the splint to prevent local pressure. For leg injuries, if splinting one leg with the other put padding between the bony places: knees and ankles. Watch for shock and treat accordingly. If the casualty is in pain, a pain-killer may be appropriate. (Depending | ||
+ | |||
+ | === 7. Snake Bite === | ||
+ | |||
+ | Assume the snake is venomous. Identify the snake if possible but do not waste time trying to catch it and maybe getting bitten yourself. The majority of bites are to the lower leg with the rest to the hand or forearm. Bites elsewhere are difficult to treat, but the first aid is the same. The current (1996) theory and treatment for snake bite is as follows; because the snake venom travels along the lymph system to the heart, treatment is to apply pressure to the affected part of the body in order to slow down the rate of travel of the venom. At a slow rate the body can rid itself of the venom. | ||
+ | |||
+ | __Signs | ||
+ | |||
+ | Puncture marks at the bite site, and one or more of the following: disturbed vision, nausea and vomiting, headache, drowsiness and fainting, sweating, pain in the abdomen, difficulty in breathing, diarrhoea, shock. | ||
+ | |||
+ | __Treatment__ | ||
+ | |||
+ | Do not wash the bite site (at the hospital, a sample of the venom can be taken to identify the type of snake), cover the puncture with a dressing then bandage the whole limb with a crepe bandage firmly (as for a break or sprain) starting from the bite down to the extremity of the limb and then working upwards. Apply a second crepe bandage over the first. | ||
+ | |||
+ | (To be continued) | ||
199609.1466126602.txt.gz · Last modified: 2016/06/17 11:23 by vievems