There’s nothing sinister or morbid about dead reckoning. No, you won’t be dead when you get there! …probably. The term originates with “dead” -adv, meaning directly. While to reckon is to count or compute. A reckon”ing” -n is the result of a count or computation. So Dead Reckoning could be described as a direct computation of position. The formal definition from the American Practical Navigator: Dead Reckoning is the determination of position by advancing a known position for courses and distances.

Gotta start somewhere, so we need an initial position (IP). Then to arrive at our estimated position (EP) some time in the future let’s travel on a constant course and speed for a certain period. We use the simple and well known relationship of speed multiplied by time equals distance:

D = S x T

Figuring a DR position graphically is straight forward, lay a straight edge through your IP and parallel to your direction of travel taken from your compass rose (or angle from the map edge), then measure off the distance computed by D = S x T, and there you are. Of course, this must be done on a chart projection, such as Mercator, where a straight line represents an unchanging course.

A numerical solution to the DR problem is a bit more involved. Using lots of trigonometry and detecting special situations, such as parallel sailing and pole crossing.

Dead Reckoning is an important part of overall route planning. When plotting a great circle (GC) course to a destination, the GC heading is only good for the small first part of the voyage, the course actually is constantly changing. So rather than constantly recalculating the GC course to steer, the process is to take the initial GC course, compute a DR position for finite time in the future. That position becomes like a waypoint from where you calculate a new GC course to your final destination.

Wash, rinse, repeat – and you end up with a navigable GC route composed of individual Rhumb Lines computed using dead reckoning. Current set and drift are usually taken into account when using DR in piloting and ocean navigation.

You also use dead reckoning in car or land navigation, but usually in a less formal way that in marine navigation. If you’re going on a road trip you naturally make assumptions about your speed of travel and figure “well after four hours of driving on the highway, I will have reached this city, maybe a good place to stop for lunch.”

Dead Reckoning is a fundamental tool in navigation. It’s used formally in graphical and numeric solutions to navigation as well as informal calculation, maybe even done just in ones head. It all comes down to estimating a current or future position given course, speed, and time travelled.

With that disclaimer in place, the other day I was chatting with Farmer Gary about how no one uses Yahoo IM anymore and he let me know about this map of the internet.

It’s not a network map showing the interconnections amongst the various nodes of the net, but instead a fanciful representation of the various places on the internet and their relative “importance.” The size of each named area being in some way proportional to the impact of a given site.

The author not only maps out the relative impact of sites, but uses geographical metaphors to illustrate curious or problematic internet phenomena, such as the “Sea of Zero (0) Comments” or “Plains of Awkwardly Public Family Interactions.”

It’s not actually a map of whole entire internet but, as the title states, a map of online communities. Nevertheless, it’s an insightful and fun map to explore.

While totally imagined, the landforms and water features are consistent with those found in the real world. Details, such as the dark coastline blur, make the map easy to read and ultimately more engaging.

The more you look at it, the more fun places you’ll find. Heck, there are places on this map that I didn’t even know existed! One of my favorite discoveries is a reference to “The White Mountains” series by John Christopher.

What really amazed me is how big Facebook really is. I hope this map is updated in the future so we can see how the social web “landscape” changes over time.

The mobile GPS navigator using dedicated hardware is history, toast, done for.

GPS hardware and software is now such a commodity that it’s a given in every smart phone produced. As far as I can tell, Navigon now sells only navigation software for the iPhone, with Android software promised for the future. How long until all mobile navigator companies drop dedicated hardware?

The market for handheld GPS units, the kind used for hunting, backbacking, and outdoor sports will be around for a while, at least until more integrated technology makes them redundant. Hand-held devices are unique in that their application is all about waypoints and position fixes rather than roads and driving directions. However, this may become more of a niche application and consequently, prices for hand-held devices will rise.

What will become of the TMC (traffic message channel) sent on FM radio station subcarriers? Some phones do include built-in FM tuners, but is only temporary as terrestrial broadcast radio becomes more marginalized. With smart phone connectivity over 3G, 4G, and WiFi there seems little benefit in sending the TMC data over a dedicated subcarrier.

The dedicated mobile GPS navigator occupied a unique place in the technological continuum, where GPS receivers, digital maps, and road routing software merged at the product level.

1. Login to your Google account and go to http://maps.google.com

2. Click on the My Maps link

3. Click on the Create new map link or the Get Started button

4. Give the map a title and description, then click the Import link

5. Browse to the KML or KMZ file then press the Upload from File button

6. Done! Your Google Earth map is now imported into Google Maps.

Keep in mind that Google Maps doesn’t have all of the same features supported in Google Earth, but things like placemarks (and polygons) play well.

What don’t you get?

• You don’t get to re-use the big search engine maps without restrictions.
• You don’t get to participate in the map making process.
• You don’t get to edit the geographical data that underpins the map.
• You don’t get freedom from ads and clutter.

What’s the solution?

Well, let me tell you about Open Street Map http://www.openstreetmap.org

OpenStreetMap is a free editable map of the whole world. The map data comes from individual contibutors to the site, and any one can participate. Frequently OpenStreetMap users organize mapping parties to get together and collect data for the betterment of the map, and to socialize with fellow map makers and geo-nuts.

OpenStreetMap allows you to view, edit and use geographical data in a collaborative way using your own survey data and GPS tracks. The map offers a clean, uncluttered look.

Publishing the Map

A flexible export feature lets you save map images in various free formats without branding or watermarks. Another handy export option is to generate HTML code for an iframe. The ever-present ‘permalink’ link give you easy access to the URL that will take to the exact view you’re looking at, which makes linking to the map on the web a snap.

OpenStreetMap isn’t the ultimate web map, it doesn’t offer turn-by-turn directions or pinpoint the nearest Starbucks – but if you’re a map maker (digital or otherwise), or if you simply want to explore a region without sponsored links and clutter then you should give OpenStreetMap a try.

OpenStreetMap is an excellent alternative to the web maps offered by the big search engines.