geodetics

I just got back from a vacation in Oceania (which is why I haven’t posted in a couple weeks). The flight path home included a leg from Melbourne to Los Angeles. During the 15 hours of sitting, I thought to myself that it must be one of the longest flights in the world.  As it turns out, it isn’t even in the top 10; it’s the 12th longest.  I’ve mapped the geodesics of the top 20 commercial flights here. With the recent problems at Qantas (and with airlines in general) some of these may change soon, but these are the current paths. Note that, because I’ve used a Robinson projection, some flights that go over the Arctic Circle appear longer than they are, so I’ve added a color scheme and listed the lengths on the map.

Data source: http://en.wikipedia.org/wiki/Non-stop_flight

Shortmom always has good questions!

These are actually survey markers, or more commonly benchmarks, installed by the National Geodetic Survey.

Geodesy, or geodetics, is the study of the representation of earth.

You’ve probably seen surveyors before, though you may not have realized. Often you will see them standing on the sides of roads, with contraptions sitting atop what are essentially very tall yellow tripods. These tools are actually highly precise and highly accurate tools used for mensuration – literally the study of measurements (typically geometric measurements, but there are all types of mensuration, really).

So when you put those two things together, the National Geodetic Survey is essentially a governmental organization that collects very precise distances, angles, and areas at various points on the earth’s surface (at least within the US), and it uses those measurements to create 2D and 3D representations of the earth (again, within the US).

These measurements and representations are used to create topographic maps, plan infrastructure, make all sorts of maps, and generally make life easier for everyone everyday. A lot of work goes into making life in the 21st century more navigable.

Benchmarks are used to ensure that measurements are taken from the same location. You’ll notice that in the top photo, there’s a triangle on the benchmark. This indicates that the benchmark is used for triangulation, and you might find other “reference” benchmarks around it that act as reference points. Often, they have arrows pointing to the triangulation benchmark, and they can come in very handy if something happens to the more important benchmark (e.g., vandalism or removal, which are illegal and carry a heavy fine).

You’ll find benchmarks at the tops of many mountains because, as you can imagine, being the highest point around can come in very handy for mapping elevation. You don’t always see them, though, and I try to take photos of them when I can, because I’m a mapping nerd. People also photograph them as proof that they summited. I have been to the top of Observation Point in Zion National Park TWICE now, and I’ve forgotten to photograph the benchmark each time! But you can see it peaking out in the lower right-hand corner of this photo:

Anyway, you can find benchmarks all over the place. Literally anywhere in the US. They aren’t always these cast, embedded metal discs, though. Sometimes they are obelisks or cairns. They’re fun to look for.

If you’ve ever heard of geocaching (a sort of treasure hunting that you do, using geographic coordinates to find the cache), there’s a similar game on the geocaching website for people who like to hunt benchmarks. If you put in your postal code (or the nearest postal code to the area in which you’d like to go benchmark hunting), it will list of all Geodetic Survey database items for that area with geographic coordinates.

If that’s too much work for you, here’s a website that will return a KML file (point file) displayed in a Google Earth plugin. Here are all of the benchmarks for the Salt Lake City area as an example:

I selected Dale Peak, the benchmark I visited yesterday (and seen in the first photo of this post), but I also see a bunch of benchmarks by my house in the valley! Because civil engineering.

Anyway, benchmark hunting is fun. Geocaching is fun. Max might be into an active, real life “treasure hunt” of sorts! Usually the cache is a small, weather proof container, and you leave a note and a little trinket with which to replace the one that you take.

If you don’t have a handheld GPS, you can use your cell phone! Apps probably cost money (like the Geocaching.com-endorsed app), but you could also use the free Google Earth app and files saved to your Google account through custom maps in Google Maps. Or just plan ahead and wing it. Because adventure!

Kilmeter Zero/ Fundamental Point

You will find these points all over the world. In classic geodetics (now mainly operated by satellites) it used to be the central point for measuring and mapping the country. As the earth is a geoid you need to used to have to use ideal ellipsoides for your region.

> the exact astronomic coordinates of the fundamental point are known

> from this point a triangular measuring net was spread all over the country

> the reference ellipsoid needs to be knows (Germany: Bessel ellipsoid. Russia: Krassowski ellipsoid. North America: Clarke ellipsoid)

> even though nowadays most countries use the intercontinental WGS84 system (geocentric) for satellite operations, the kilometre zero points still remain. Here some examples:

Madrid

France

Moskow

Nihombashi

Sources: http://www.cs.hs-rm.de/ - http://www.cnes.fr/ - http://www.euclideanspace.com/ - none of the pictures belong to me

Southwest view at Rotten Row No. 1 station from Interprovincial Boundary Survey, AB/BC, 1915. Credit: A.O. Wheeler/Geodetic Survey of Canada/Library and Archives Canada/e002419415. The images in this series were copied as part of the Rocky Mountain Repeat Photography Project, U. of Victoria. This project consists of the pairing of thousands of historical Dominion Lands Survey photographs and current repeat images.

youtube

Here’s this because I really like geodetics.

In this book, two experienced researchers into prehistoric culture have made a remarkable breakthrough in understanding the system by which prehistoric monuments were designed and placed on the landscape. This system, a precision geodetic science, enabled the megalith builders to mark out vast geometric shapes across the landscapes. At key points they erected their magnificent stone temples and markers, whose dimensions and locations encoded their knowledge of the Earth and sky. Key Points: Prehistoric Britons knew the dimensions of the Earth and had undertaken an accurate survey of the British Isles, pre-3000 BC; The major time periods of the Sun and Moon were encoded within their monuments, measures and system of land surveying; This prehistoric system was still being applied in the Middle Ages, and remnants survive today as the English Foot, Nautical Mile and Knot.

Whenever things go a bit sour in a job I’m doing, I always tell myself, ‘You can do better than this.’
-Dr.Seuss .

#iphoneonly #vscocam #callofduty #surveying #landsurvey #theodolith #totalstation #geodetic #gps #waterpass #leicaviva #leica #topcon #sokkia #notforsale #haha by azzanurfadhila http://ift.tt/1ydBNdQ

#geodezja #surveyor #surveying #vscogallery #vzcopoland #vsco #vscocam #Geodesy #Geodetics #Geodézie #Geodezia #Geodezie #Geodesie #Geodesi #Geodäsie #Geodesia #Géodésie #Geodezija #Геодезия #Geodézia #Jeodezi #Geodésia #surveylife #vscogallery by k.r.i.s.b.a http://ift.tt/1alJCmK

ESSC co-organizing the FOSS4G-PH 2014 workshop at the Philippine Geomatics Symposium 2014

ESSC co-organizing the FOSS4G-PH 2014 workshop at the Philippine Geomatics Symposium 2014

By admin

Environmental Science for Social Change, OSGeo Philippines, the University of Philippines Department of Geodetic Engineering FOSSLab, and OpenStreetMap-Philippines will organize a series of workshops and technical presentations showcasing free and open source for geospatial (FOSS4G -PH) as part of the Philippine Geomatics Symposium (PhilGEOS) 2014.

The Philippine Geomatics Symposium or…

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March 17, 2014

Presentation day!

Things I learned:

  • Sir Barnes Wallis
    • Inventions:
      • Geodetic air frame
      • Vicker’s Wellington air bomb
      • Bouncing bomb
      • Missiles Tall Boy and Grand Slam
        • How would air travel and war be different without these inventions?
  • Henry Bessemer
    • Invented a way of producing steel that made it econmically viable, cheap, and easy
      • Steel fortifies transportation, homes, medicine, hygiene, etc.
      • Steel builds industry.  Steel builds our world.
        • Where would we be today without steel?

#geodezja #surveyor #surveying #vscogallery #vzcopoland #vsco #vscocam #Geodesy #Geodetics #Geodézie #Geodezia #Geodezie #Geodesie #Geodesi #Geodäsie #Geodesia #Géodésie #Geodezija #Геодезия #Geodézia #Jeodezi #Geodésia #surveylife by k.r.i.s.b.a http://ift.tt/1Oxt4qR

#geodezja #surveyor #surveying #vscogallery #vzcopoland #vsco #vscocam #Geodesy #Geodetics #Geodézie #Geodezia #Geodezie #Geodesie #Geodesi #Geodäsie #Geodesia #Géodésie #Geodezija #Геодезия #Geodézia #Jeodezi #Geodésia #surveylife by k.r.i.s.b.a http://ift.tt/1HZH88T

#geodezja #surveyor #surveying #vscogallery #vzcopoland #vsco #vscocam #Geodesy #Geodetics #Geodézie #Geodezia #Geodezie #Geodesie #Geodesi #Geodäsie #Geodesia #Géodésie #Geodezija #Геодезия #Geodézia #Jeodezi #Geodésia #surveylife by k.r.i.s.b.a http://ift.tt/1IzxjBQ