le letture di TANTO

MAKE: The Bloop of Cthulhu?

Mon, 16 Nov 2009 14:00:00 -0800

This may be one of those situations where my love of a good story gets me in trouble with the more hard-minded scientific types among you, so please understand first that this is all intended in fun. Nonetheless, there are some intriguing facts here.

During the summer of 1997, the U.S. National Oceanic and Atmospheric Administration (NOAA) repeatedly detected an extremely powerful underwater sound on an array of Cold War era hydrophones originally installed to listen for soviet submarines. "While it bears the varying frequency hallmark of marine animals, it is far more powerful than the calls made by any creature known on Earth." Phil Lobel, a marine biologist at Boston University, purportedly "agrees that the sound is most likely to be biological in origin," although his opinion appears to be in the minority. (Both quotes from this article at CNN.com.) The approximate origin of the sound has been identified as 50 S x 100 W, which is almost exactly the same latitude as Lovecraft's fictitious sunken city of R'lyeh, at 48 S x 123 W, although it is 1000 miles distant in terms of longitude. [Thanks, Maredith!]

You can listen to a sped-up version of "The Bloop" on the NOAA website here.

MAKE: Regular GPS not accurate enough? Try RTK-GPS!

Fri, 13 Nov 2009 13:00:00 -0800

Want to fly your plane or drive your car using GPS signals, but finding that your receiver just isn't accurate enough to make things work? Well, MAKE subscriber Bruce Mueller writes in to point us at an impressive solution: an open-source real time kinematic GPS receiver. Researchers Tomoji Takasu and Akio Yasuda of Tokyo University developed the RTKLIB library to perform the RTK-GPS calculations, and then ported the whole thing to run on a low-cost beagle board and commodity GPS receiver. Want to try it out? Full source code, circuit layouts and instructions are provided on their site.

So, how does it work? A GPS receiver normally works by measuring the delay between an internally generated signal and one received by a satellite. This specially crafted signal makes it possible for the GPS receiver to find and latch onto the satellites signal, however it's wavelength limits the accuracy of the receiver. The real time kinematic system gets around this limitation by measuring the phase delay in the carrier signal. Because this signal has a much sorter wavelength, it is possible to make a system that is accurate to the centimeter.

MAKE: Google Maps Navigation ported to G1 & MyTouch

Fri, 13 Nov 2009 04:00:00 -0800

If you own an older Android phone and were curious about Google Maps Navigation, but were afraid to ask, here's instructions to get it running. [via AndroidCentral]

MAKE: Nonexistent town in Google maps

Thu, 05 Nov 2009 08:48:27 -0800

Interesting article in the Telegraph about "Argleton," a town that appears in Google maps but does not, apparently, exist in the real world. The best theory I've heard is that the town is a "trap" intended to catch those who steal map data. [Thanks, Glen!]

MAKE: GPS-enabled puzzle box opens only at Île-de-Bréhat, France

Mon, 19 Oct 2009 06:39:16 -0700

The first presenter at last Thursday's Dorkbot Austin was a gentleman named Mikal Hart, who described his "Reverse Geocaching Puzzle." Designed and built as a wedding gift for an old friend moving to France, the box incorporates an Arduino with a custom shield. A prominent button on the lid, when pressed, returns a distance, in kilometers, on the LCD display (if a GPS signal can be acquired), and counts button-presses up to 50 attempts. No directional information is provided, so the box must be moved about in order to triangulate the location it wants. Mikal also included a cunningly-disguised back door to allow it to be opened in the event of battery failures or bugs.

andrea: Curso de gvSIG Online

Fri, 09 Oct 2009 09:33:00 -0700

Curso de gvSIG Online

Esta dica vem do blog do Edmar Moretti, que é o curso online de gvSig que foi montado pelos alunos do CEFET de Goiás, sob orientação do Prof. Nilson Ferreira.

O gvSig pra quem não conhece é um software para Sistemas de Informações Geográficas que dispõe de funções para aquisição, armazenamento, gerenciamento, manipulação, processamento, exibição e publicação de dados e informações geográficas.

Quem estiver interesse no curso sobre o gvSig, segue o link: http://www.lapig.iesa.ufg.br/lapig/cursos_online/gvsig/index.html

Fonte: Blog do Edmar Moretti

Posts Relacionados

[link to original | source: Planet OSGeo | published: 5 hours ago | shared via feedly]

Permalink

andrea: OpenStreetMap Formula 1 Circuits

Fri, 09 Oct 2009 09:32:52 -0700

OpenStreetMap Formula 1 Circuits

OpenStreetMap Formula 1 Circuits

OpenStreetMap Formula 1 Circuit - Circuit de Monaco (Monaco)

OpenStreetMapper 'kevjs1982' has been busy mapping Formula 1 circuits across the world using OpenStreetMap.

"I have been putting a page together showing all the Formula 1 grand prix circuits on OSM and this has shown how random motor racing circuits have been tagged in the past

Highway=road, Highway=motorway, Highway=track, Highway=service, Highway=unclassified, and leisure=sport have all be used.

Relations for the Grand Prix circuit have been created and where the circuit is a dedicated one the highway has been changed to raceway.

Annoying now I've been through the lot it seams that the highway=raceway tag has been abandoned (I could have sworn it wasn't last week) although Mapnik renders it (see Donington Park, Silverstone, Hockenheimring, and Nürburgring for some old highway=raceways) - typical!

If you are in Montreal or Valencia and looking for something to map you could do worse than double checking the grand prix circuits out - looks like both are generally part of the local cycle networks and some areas are probably better tagged as something other than Raceway (current) or Track (previous) - in particular Valencia looks to have been redeveloped a lot since the aerial photography was taken and was originally laid down as a highway=track on top of open ground and other roads.

If you want to see how much stuff can be tagged round a Grand Prix circuit while bringing Potlatch to it's knees than the two German tracks are good places to check out!

Alas, not all tracks are in Open Street Map at present - 上海国际赛车场 (China), İstanbul Park (Turkey), Marina Bay (Singapore), 鈴鹿サーキット (Japan), Yas Marina (Abu Dhabi), and Korean International Circuit (Korea) are missing, and Wikipedia doesn't even know where the Indian track is (unsurprisingly all the new ones outside aerial mapping coverage).

mapperz correction
http://en.wikipedia.org/wiki/Jaypee_Group_Circuit
http://en.wikipedia.org/wiki/Indian_Grand_Prix

Diary entry centred on the Nürburgring Nordschleife - where else could you do so really?

Formula 1 OpenStreetMap can be found at:
http://kjs.me.uk/osm/f1.php - shows all the tracks on this years and next years calendar (aside from India).

So if your interested and have some knowledge either in formula 1 or helping openstreetmap fill the gaps then you can help.
Starting point is http://wiki.openstreetmap.org/wiki/Main_Page
The OpenStreetMap - http://www.openstreetmap.org/index.html

Source:
http://www.openstreetmap.org/user/kevjs1982/diary/8217

Mapperz News Blog

[link to original | source: Planet Geospatial | published: 7 hours ago | shared via feedly]

Permalink

andrea: Apple Has a New Geo Team

Sun, 04 Oct 2009 13:32:34 -0700

Apple Has a New Geo Team

An article on a ComputerWorld blog announces that Apple quietly bought PlaceBase, and that the founder of that company, Jaron Waldman, is now part of the “Geo Team” at the company. Read more related Spatial Sustain posts:China Bans Map TradingMapSherpa Launch Forges Whole New Geo Business PlanOrtelius Aims to Unleash Both the Art and Science of [...]

[link to original | source: Planet Geospatial | published: 3 days ago | shared via feedly]

Permalink

MAKE: My people call them maize mazes

Thu, 01 Oct 2009 06:48:40 -0700

Cool post over on Hack-A-Day about corn maze entrepreneur Scott Skelly, shown above with his trusty GPS-enabled riding lawn mower. Scott explains his maize-maze-making process thusly:

A maze starts as nothing more than a large field of corn. The design is created using a computer, then translated into GPS coordinates by fitting it into a field whose outline coordinates were previously captured on foot. Once the field coordinates are reconciled with the map design the data is used in one of two ways; the routes can be made by tilling under a path when the corn is very young, or more commonly it is cut lawn-mower-style when the corn is anywhere from knee-high to full grown. This corn-meets-satellite hack makes for a whole lot of fun!

MAKE: DIY Street View camera

Wed, 30 Sep 2009 05:00:00 -0700

As part of a course at the United States Military Academy at West Point, maker Roy D. Ragsdale developed a prototype Street View-like camera using a laptop, $300 in off-the-shelf components, and open source software. A Python script captures eight 1280x1024px JPEG files that are then stitched together and uploaded to Google Earth.

Construction was straightforward. On a flat octagonal heavy-cardboard base, I glued small posts for the cameras' clips to latch onto. I aligned each unit and then placed the USB hubs and the GPS receiver in the middle. I secured the cables with Velcro and sandwiched everything with another piece of cardboard. The whole thing's the size of a small pizza box, weighing less than 1 kilogram. Excluding the notebook (a 2-gigahertz machine with 512 megabytes of RAM running Ubuntu Linux), the hardware cost about $300.

[thanks, Erico]