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Messages - Brian

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Navigational Questions & Answers / Re: Map Projections
« on: January 03, 2013, 09:32:16 PM »
Very, very well said, Lost Soul.  And very well written, too.  (A previous comment of mine was withdrawn, too.  It did not go to really address the issue Barry G raised)

Navigational Questions & Answers / Re: Map Projections
« on: January 02, 2013, 12:52:15 AM »
Almost all the SAR units in Oregon's counties use UTM.  There are probably several reasons for this:  conceptually, everyone can grasp what a meter is because it's a distance slightly greater than a yard. 

But with Lat/Long, you're talking about angles and parts of angles.  You start with 360 parts, and then 60 subparts of each part, then 60 subparts of each subpart, and decimal subparts of subparts of subparts. 

There's the additional complication that there are DDD.ddddddo, DDDo MM.mmm" and DDDo MM' SS.sss".  Then, there's the whole "confusion" wrt longitude, the distance of any part or subpart of which changes with latitude (1 degree of longitude at the equator is a much greater distance than 1 degree of longitude at 90o latitude).

For novices, it's difficult conceptually, and if they master the concepts, it's somewhat difficult to apply unless you use the 3 Lat/Long formats all the time.

The people in our unit are volunteers, and they find all that angle stuff baffling and don't have the time to master it (it would be fun to teach it — to demystify it — though).  If explained clearly and concisely, UTM is much easier for them to understand and use.

Also, the National Grid of the US is based on the Military Grid Reference System, which is like a (needlessly complex, IMO) UTM grid.  Which makes it advantageous for SAR units, at least, to be familiar with similar system rather than Lat/Long.

Having said all this, we teach our people that they need to be able to translate UTM to the DDDoMM.mmm" (using their GPS/SatNavs) because air and marine (ocean) assets use that format. 

At least, that's how I've put things together.

General Discussion / Cheap Dual-Band HT
« on: December 31, 2012, 07:10:49 PM »
If you're interested in a cheap handheld dual band (VHF/UHF) 5 watt radio, with narrow band capability, check this out:

The cost is $65 US for an individual one, and $300 US for a six-pack.  The radio gurus I know think it's a heck of a bargain, and I sprung for one for Kate's Christmas.  It looks okay to me, though the instruction manual could be a bit better, and I'll probably be getting a second one.  And several of our SAR folks (as of now, the people of our rope team) are considering it, too.  I think we'll get at least one six-pack. (1)

My radio gurus recommend springing for the programming cable (programming software is free), but to skip the high-gain antenna (which apparently  doesn't offer much advantage).

The down side:  Unlike our Yaesu FT-60R radios, it probably isn't very weatherproof, nor will it accept AA or AAA batteries.

But it's very small and I've never seen anything like it for the price.

(1)  Our agencies are changing from wide-band to narrow-band, which is a capability our current radios lack.  This has engendered quite a bit of grumbling amongst the troops, since many of us have gotten our ham licenses and purchased several wide-band radios each, at considerable personal cost, specifically for our SAR activities (base station, with antenna, coax cable and power supply; mobile radio for vehicle with antenna; and HT, plus accessories like extra batteries, speaker mic, high-gain antennas, etc.).

Just FWIW.

Satnav (GPS GLONASS COMPASS Galileo) / Iranian spoofing
« on: December 18, 2012, 04:58:05 PM »
Interesting post on the entitled: Iran Hacks Ships At Sea

The never-ending game continues.

Key Grafs:

". . . Iranian agents are offering deep discounts to buyers willing to create false documents and move the Iranian crude. This is risky, for those who get caught can be prosecuted, jailed, and fined. But Iranian smugglers know who is willing to take chances, if the payoff is large enough. Selling oil at discounts of 30 percent or more still costs Iran. So also does the expense of secretly buying tankers that will pretend to belong to another country while moving the black market oil. This is where the false GPS locations are put out by the transponders.
"The U.S. and the UN are alert to these schemes and the great game of cat and mouse is on. . . .
". . .This can work for a while, but a nation with lots of recon satellites, warships and cooperation from most of the world’s shipping, can get around this.
". . .The Iranians are aware of the satellites and other means of double-checking transponder data and is constantly coming up with schemes to confound the American snoopers. Since Iran has been under sanctions for decades for being an outlaw state, threatening more punishment is seen as a challenge not a threat."

Navigational Questions & Answers / Re: Question for Lyle (and the group)
« on: December 16, 2012, 06:08:10 PM »
While practicing with my Etrex and the new settings Lyle gave me I tried something and here's the results.

1. With the sat/nav set to Nad 27 conus I took a waypoint of my home in the driveway:
    RESULTS = e0601547
2. With the sat/nav set to Nad 83 (datum on the USGS map) taken in the same spot in my driveway:
    RESULTS  = e0601577
3. Using a USGS map and a corner Roamer scale I read = e0601560

My Conclusions:

      Follow the advice that when using a sat/nav set it to the datum on the map because you could be 25% off as in this case, and 25% of 1,ooo sq. meters is as you know 250 meters which is a good amount in say a wooded area or passing a person laying down unconsious.

My math could be off a bit, but you guys get my point! I love this stuff!


Good for you for experimenting.  Very good for you.  I have two additional thoughts.

First, IMO there are two kinds of "knowing" — intellectual and emotional.  In a previous life, I sometimes taught how to diagnose some things.  My students dutifully memorized what I told them to and answered test questions correctly.  Yawn.

But there came a time when they actually had to commit themselves to what they learned in a real-life environment, and when they did, and they found what they'd learned actually worked, they were impacted emotionally in a way which cemented their knowledge.  (I know because up to three years after I'd taught them, some would return to tell me, with wide eyes and surpassing enthusiasm:  "Remember what you taught us about ...?  Well, it works!")

Having compared coordinates for the same location using different datums, I suspect you'll never forget the importance of using the correct datum.  And that's a big deal, at least in these parts.

Second, in teaching GPS/SATNAV to our SAR members, we strongly emphasize the importance of using the correct datum.  We have a powerpoint slide of one location correctly placed on a map with the proper datum, but incorrectly placed using 5 - 6 incorrect datums. 

Another slide shows what happens if you go to the right coordinate numbers, but you are using the wrong datum:  you're on the wrong side of a river in a deep valley with no way to communicate with the outside world and with the only river crossing 2 miles away along a gnarly trail.

In fact, every time we have a discrepancy in location (my receiver doesn't agree with your receiver) the first thing we check is whether or not we are using the same datum.

FWIW.  We (our county and the other 8 CORSAR counties) used to use NAD27, because it was the datum used to create all our 1:24,000 USGS paper topo maps. 

But we changed a year or two ago to WGS84 because we no longer use topos printed by the USGS: we now print our own maps using National Geographic TOPO! or TNP, and can select which datum we wish to use.  (Air and Marine assets use WGS84, and it's just easier for us to do so too.)

Reviews, Suggestions and Advice / Re: New Garmin Etrex 10 First Impressions
« on: November 06, 2012, 04:56:41 AM »
Mikee a few pointers:

[ . . . ]  4.   Assuming you have set it up properly, as in the right map datum etc., it might be best for the very first time you use it to leave it sat collecting satellite data for 20 minutes, simple place it somewhere where there is a good clear view of the sky and it collects all the ephemeris data for your area

Yes.  When I go to a new location, I turn my 62s on, stay put, and let it settle in for 20 minutes or so. 

Then, I show anyone within range the track it has recorded.

Though the unit remains stationary, it records quite a track.  It really makes the point, for those who take UTM numbers as some sort of scientific absolute, that those numbers are not an absolute.  It's a great way to make the point that the "accuracy" notation is a statement of probability worth taking into consideration.

New Member Introductions / Re: Hello to all
« on: October 01, 2012, 05:53:47 PM »
And welcome from me, too. 

The depth and breadth of knowledge of those who post here, and the courtesy with which they address one another, is inspirational.

General Discussion / Re: For Lyle
« on: September 28, 2012, 06:01:07 PM »
Thanks Mate ;)

I am never quite sure whether to admire the very independent state of California or think that they are nuts. I was very fortunate back in the 90’s to spend a great deal of time there, and think that northern California is one of the best places to live in the world.

There are tongue-in-cheek attempts from time to time for northern California and southern Oregon to merge into a single state, that of Jefferson.  Much the same terrain and worldview, but separated both from Sacramento and points south, and from central Oregon and points north.

General Discussion / Re: Echoes of the Cold War!
« on: September 28, 2012, 05:52:39 PM »
I wonder if we aren't knee-deep in a cold war at this moment . . . one in which cyber attacks are in widespread use against Iran. All very hush hush, of course, but it's inconceivable to me that Stuxnet, Flame and Duqu, and a downed stealth drone, are all there is to be seen.

I guess I'm less concerned about physical attacks on satellites than I am about corruption and destruction of a major part of our computer-based world.

I hope my worries are misplaced.

Satnav (GPS GLONASS COMPASS Galileo) / Re: GPSMAP 60 replacment
« on: September 20, 2012, 07:54:47 PM »
In the past week I've upgraded from a 60Cx to a 62s. It was very good value with the OS map bundle thrown in.

 . . . I'm not familiar with the Montana other than knowing it's touch screen and named after Joe.


Satnav (GPS GLONASS COMPASS Galileo) / Re: GPSMAP 60 replacment
« on: September 20, 2012, 06:00:03 PM »

Moving from a handheld Garmin 60 series to a 62 mapping satnav will be intuitive, and yes, it is an excellent piece of kit. If you buy one get the 62s and not the 62st and buy a mapping bundle. The st is more expensive and the topo mapping redundant if you get Ordnance Survey mapping. . . .

I agree completely.  Our SAR unit went from 60Cx to 62s and, while there are some differences (especially in how tracking and waypoints are managed) our members had little trouble adapting to the change.  Of course, part of that is that I configured the 62s as much like I'd had the 60Cx units as I could (you can configure the 62s units with different looks ["profiles"], each with its own emphasis). 

We use only AA batteries in our units, never the rechargeable ones.  Unlike the 60 series, you can use both alkaline and Lithium batteries in the 62 series.  (If you change from Alkaline to Lithium, or vice versa, you should change a setting in the unit to reflect which battery you've installed.)

I'm completely unfamiliar with the Montanas, but they sound like jewels.

Maps / Re: what do you do when you don't have good maps?
« on: September 15, 2012, 05:15:51 PM »
What about Google Earth images and creating waypoints and routes on a handheld satnav, to follow, as reference and possible escape routes?


We conducted a mock search a week ago of an area for which our 1:24,000 topo maps show precious little . . . merely contour lines and buildings . . . but which do show some non-existent roads which had been planned but never built.

(In other words, topo map features that are not present are depicted, features that are present are not depicted!)

In reality, the terrain was far more convoluted than the maps showed, and the region was crisscrossed with dozens of trails, none of which were represented on the topo maps (paper or computer-generated).

Google Earth proved to be very useful:  most of the trails showed up and one could gain a real appreciation for the contours of the terrain, much better than one could see even on a digital map with "shadow" enabled.

Using that Google Earth map, and with (Google Earth generated) coordinates defining search areas, our people were able to search effectively.

Those Google Earth maps are a good resource, sometimes even better than a standard topo map.

Wilderness Survival / Re: Psychology
« on: September 02, 2012, 10:37:28 PM »
... For example, training that reduces the burden on working memory by laying down procedural memories on how to use safety equipment could help lead to purposeful action during an emergency. This highlights the need for safety training to incorporate a practical element, not just to rely on reading a book or watching a video. . . . That means that being prepared in skill and to some extend in your mind, can help. . . .

(My emphasis.) 

That's very well put, IMO.  After the disaster-facing soul has grasped that s/he's in a major pickle, then the training kicks in, if the experience of training is available and the person need have only enough will-to-survive to begin implementing the procedural steps.  (I guess what I'm thinking is that the more extensive the training and experience, the less important would be the will-to-survive.)

I've never been in combat, but it seems to me that somewhat the same mechanism might be operative when, say, a unit is ambushed ("I didn't have time to think.  I just reverted to my training.").

It seems to me that for the will-to-survive to be really important, it would be when an individual was confronted by a situation he'd never contemplated.  For example, for someone who's been trained for wilderness survival, even if that training is limited, his will-to-survive would be of much less importance to his survival if lost in the wilderness than if, for example, he found himself adrift at sea in a lifeboat, having never even contemplated that situation.

Just some thoughts from a guppy.

Trip reports / Re: Kinder Scout
« on: September 02, 2012, 05:21:07 PM »
Enjoyable to read, and the pictures are truely lovely.  It's so different from what we have!

Thanks for sharing.

Wilderness Survival / Re: Psychology
« on: September 02, 2012, 05:18:44 PM »
I'm fascinated by this thread.  Thanks to all who have contributed to it.

Adi - STOP is terribly important.  And as a companion to a good knife, I'd have a saw of some sort.  I prefer a substantial folding pruning saw with a 7 - 10 inch blade.  Cheap, light weight and safer and more energy efficient cross-cutting a branch than swinging with a knife.  Also, in our evergreen forests, you can remove boughs from trees (insulation) much more easily with a saw than with a knife (you can't swing your knife within the density of the branches). 

With the saw, you can make a baton to strike the spine of your knife for wood-splitting and for chopping, you can "square" the ends of branches, precisely cut lengths, etc.

"State of mind" is crucial.  I try to get people to a survival mentality by providing them with a familiarity of what to expect if lost in the woods, what equipment they should have, and how to use their tools.  IF they practice a little, much of the terror of the unknown dissipates. 

In essence, knowledge, proper equipment and practice should help create state of mind conducive to survival.  Or so I hope.

In the way of shelter equipment, I also stress taking a 4 mil thick plastic contractor's trash bag as a last resort.  Cut a hole on the fold near the closed end for your face, and climb in if the worst comes to the worst.  Cheap, light-weight and effective.

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