Land Navigation Resources (Video, Powerpoint, Websites, etc.)

[Shoobe01]

There will be a land nav course (or portion of a course) later on, but for anyone who wants to get a head start, or feels rusty and wants to get a refresher, I've started making some videos (with a convenient device that gives good closeups from above) for each of the key aspects of compass and map use, and some other topics that are interesting also.

I think this is a terrible place for this, but there's nowhere else reasonable on the forum, so here it goes for now.

I have, after lots of discussion with some others and some of the AAR information, reconsidered some of the land nav training again. I am always tweaking it, but will probably change significantly the next time it is taught, to get the most important points really, really drilled in.

To help everyone now, and as part of my thinking to provide additional topics as students look for them, after class when there is more time, I am going to use some gear I have to make a series of videos instructing on specific topics of land navigation. Here they are in the intended viewing order (which is not the order they were made):


1 - Introduction to the USGI lensatic compass:
Part 1) http://www.youtube.com/watch?v=SzCFqnzt1DU
Part 2) http://www.youtube.com/watch?v=J5GKGq379xE

2 - How to find a position given to you in MGRS coordinates on a map:
http://www.youtube.com/watch?v=EAtq3Y48334

3 - Finding grid locations from a point on the map:
http://www.youtube.com/watch?v=sbzwIF0b89A

4 - Lock a course into a compass from two known points on a map:
http://www.youtube.com/watch?v=H4SKU20vVL0

5 - Details about declination:
http://www.youtube.com/watch?v=nycp7SjZ8HA

6 - Customizing your protractor, and how to use the three features of it:
http://www.youtube.com/watch?v=rD0d29CuTjQ

7 - Larger scale grid work; UTM Zones, MGRS 100,000 m grids and so on:
http://www.youtube.com/watch?v=Mw8_vuqXWpA


There may be more later, if I can find a way to do a video on terrain association. And these are all for the USGI compass,  we'll probably do the whole thing again for commie compasses. I'll be sure to wear a furry hat and speak in an accent the whole time. And I guess I can make some on rangers for the brits (?) and anyone else who carries one of those, if you guys need the help with them as well.

[Bane]

Still hate myself for missing ROTC the day they learned land nav...

[tascabe]

East Wind Training Command teaches it better anyway

[Shoobe01]

On the off chance you've been waiting until I finished posting to view these, now is the time. All are up for a while, and everything (for NATO) but pace count and terrain association is covered. And I guess maybe an overview of GPS.

[Shoobe01]

Since we don't have a good "Resources" section of this site, I'm gonna keep adding land-nav resources and answers to questions about classes I get, right here.

The slideshow about GPS that I made is available here:
http://www.slideshare.net/shoobe01/gps-for-light-infantry-leaders-presentation
(If any admins want to mess with this, like YouTube you can embed the slideshow... but I can't do that in a forum post).



There was a question about "datum" during the GPS lecture that I glossed over. This is quite nerdy and advanced, but for those who care, here is my summary of it it.

To make sure that two specified locations match up to each other, and the right place on the ground, you need three things to match:
- Projection
- Coordinate system
- Datum

Projection is the cheat regarding the part where maps are flat (always, even digital computer maps) and the earth is (roughly) a sphere. If you haven't already done so, look around at all the different ways a world map is projected. A couple of circles, a big oval, a sort of rectangle with rounded ends, that weird tapered slice thing. Those are all compromises to try to get the most useful map for the whole world. We are using very small areas, so always have a projection that minimizes distortion over ranges a few dozen or hundred miles (all sizes are the same, right angles are right angles still, etc.). These do not work at large ranges, but it's all worked out for you anyway so don't worry about it.

The coordinate system is the part where we use MGRS vs. (one of many variants of) Lat/Long. You've figured that one out I suspect. There is a conceptual overlap between the projection version of UTM (the basis of MGRS) and the coordinate system version of UTM, but since we use MGRS, we can pretend it's not an issue.

Datum is a fudge factor around the part where the earth is not perfectly round know how to perfectly measure it anyway. It's all getting better, and since the 80s satellite surveys mean the new, becoming-most-common datums are as close to perfectly accurate as we need. That's NAD83 and WGS84. But in the old days, they had to calculate everything, and it was always a little wrong. Always. Not only could two surveyors never agree, one guy doing it twice wouldn't agree. So long ago they set various default values for what is called the Geoid (or the mathematical model of the earth's shape and size) not worrying too much about whether it was right. Every country has several. The US has settled on NAD27, which is fixed (Geoid zeroed to the earth) at a point on Meade's Ranch, Kansas. Right there, everything is fine, but as you move away, errors pile up and by the time you get to the coast things are pretty far off.

Anyway, the medium version of this is: Position values are not absolute, but are /calculated/, so if you don't use the right datum, your position will be different from someone else's (neither are "wrong" per se, just different).

The short version is: Read the marginal data, and make sure you are always talking the same datum language. If you use a GPS with a map, make SURE you check for this, and if you go to Azerbaijan or Oklahoma, be prepared to change the GPS to give you accurate positioning.

[cannon fodder]

Since we don't have a good "Resources" section of this site, I'm gonna keep adding land-nav resources and answers to questions about classes I get, right here.

don't we have one accessable from the main site(not forum)?

[aswayze]

we do have a place for this, we just need to let Misha get caught up on other stuff before we get around to fixing that area the rest of the way up. 

[Shoobe01]

Now that (a month and a half after I asked) there /is/ a place for resources, I'll just go ahead and start putting stuff in this thread, and not worrying about organization. It'll get caught up eventually.

Making Maps
Since a bunch of people keep asking, instead of responding over email, I'm gonna make a very brief primer here.

How I make my maps is unimportant. I use several professional (read: $3-600) graphics programs, and a (cracked) $1800 plug-in for one of them. I am doing increasingly insane things, and either interpreting USGS SDTS DEM elevation data, or hand-tracing the raster information, so we can edit the maps as we please. This is how every EW map has been. Most others are a mixture, and we're moving to this.

The easy way, and still a lot of the training maps, is to use the USGS DRG raster images. These are pretty much just scans of the actual 7.5 min paper maps you can still go buy. Here's a one and only place to get them dead free:
http://www.topoquest.com/

You can go in there, find locations by searches (not as easy as google maps, but not bad) or coordinates or whatever, then drive around zooming and panning and so on.

But we all want MGRS grids. So once you found your location, you want to instead get the full map sheet. Like this page:
http://www.topoquest.com/map-detail.php?usgs_cell_id=13734

This is near my house. SOME sheets are unavailable, for unclear reasons (like the one around my house).

Download the large .TIFF file. This one is called o39094a7.tif

Look at the edges of the map sheet. You will see little ticks and numbers. Near the corners are lat/long. Ignore them. All along the edges are others, which should look familiar. These are UTM/MGRS/USNG numbers. With them, you can simply draw lines straight across the map from one to the corresponding tick on the other side, and when all done you have a map sheet with 1000m grid lines. I used to do this with a ruler and pencil back in my pre-digital backpacking days (to line up the compass, if nothing else).

You will do this with a computer, and once it's done, you can crop the map down to the size you need only. To get 100m grids, you'll have to figure out how your computer program works a little more, and simply draw lines at perfect 1/10th intervals. Notes:
- The lines will NOT be perfectly straight up/down and left/right. USGS maps are aligned to TN, not GN.
- The coordinate numbers are in US military map format. They are UTM, but the first digit or two is smaller. Ignore that digit as always for MGRS purposes.
- UTM labels are sometimes dropped if there isn't enough room. Just look above and below and count to fill in the gaps. But don't miss one because it's unlabeled.

[Shoobe01]

Somehow, a bunch of my videos were set to "Private" but now I know, so have changed it. If you have problems getting to any of the resources I have posted, tell me and I'll try to fix it.