Musings

Relating Latitude and Longitude to Everyday Distances

markwarren — Fri, 07 Oct 2011 02:21:01 +0000

Latitude and longitude notations often include six decimals of precision, but how close does that get us? Starting with the nautical mile helps relate lat/lon coordinates to everyday distances. HowStuffWorks.com explains

“The length of a nautical mile is based on the circumference of the planet Earth. If you were to cut the Earth in half at the equator, you could pick up one of the halves and look at the equator as a circle. Then divide that circle, or arc, into 360 degrees and divide each degree into 60 minutes. A minute of arc on the planet Earth is 1 nautical mile. This unit of measurement is used by all nations for air and sea travel.”

Most of us don’t normally pilot ships or airplanes though and commonly use other linear distances like kilometers and miles. For the conversion examples that follow, let’s use the coordinates of the USGS office in Menlo Park located at latitude and longitude

37° 27′ 22.86″ N, 122° 10′ 15.6714″ W
37.456350 , -122.17102

The notation degrees° minutes′ seconds″ converts to decimal notation as shown here and then we can calculate typical distances corresponding with each position in the notation:

37 + 27/60 + 22.86/3600 = 37.456350
37°  27'     22.86"
 |    |       |  |
 |    |       |  +- 1/100 of an arcsecond = 1.0127 feet
 |    |       +---- One arcsecond    =  1 nautical mile / 60 = 101.27 feet
 |    +------------ One arcminute    =  1 nautical mile  = 1.15077945 statute miles
 +----------------- One (arc) degree = 60 nautical miles = 69 statute miles

In the decimal notation of the same latitude, each position corresponds to the following north/south travel distances:

37.456350
 | ||||||
 | |||||+--- 0.00006 naut mi. = 0.3646 feet = 4.3748 or 4-3/8" inches = 11.112 cm
 | ||||+---- 0.0006 naut. mi. = 3.646 feet  =   1.1112 m
 | |||+----- 0.006 nautical mi= 36.46 feet  =  11.112 m
 | ||+------ 0.06 nautical mi.= 364.6 feet  = 111.12 m
 | |+------- 0.6 nautical mi. =  0.69 statute miles=   1.1112 km
 | +-------- 6 nautical miles =  6.9 statute miles =  11.112 km
 +--------- 60 nautical miles = 69 statute miles   = 111.12 km

Longitude lines. Traveling N/S along one changes your latitude.

(For reference, 1 nautical mile is defined as exactly 1.852 km and is about equal to 1.1508 statute miles.)

Moving one arcdegree of latitude north or south by traveling along a longitude line represents the same distance anywhere on earth.

One degree of E/W travel requires different distance at different latitudes.

Moving one arcdegree of longitude east or west by traveling along a latitude line, however, represents different distances depending on the cosine of the latitude’s degrees north or south. At higher latitudes, traveling one arcdegree east or west covers a smaller distance because circles of latitude are smaller at higher latitudes.

For example, in Caracas at 10 degrees north latitude, traveling one arcdegree along that latitude line represents east/west travel of:

1 arcdegree = 1 naut. mi. * cos(10 deg) = 0.985 nautical miles = 1.333 statute miles

but at 37.45635 degrees north, 1 arcdegree of east/west travel represents just:

1 arcdegree = 1 naut mi. * cos(37.45635 deg) = 0.7938 nautical miles = 0.9135 statute miles

These calculations are close to correct, however, the Earth is not quite a perfect sphere and so professional geodetic measurements use a mathematical model of those imperfections called a datum. For more conversions, and pointers to the nuances introduced by geodetic systems, see http://transition.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html .

Without access to professional surveying equipment and geodetic correction software, five decimals or 1/10 of an arc second, representing around 1m of accuracy, is about as accurate as a consumer GPS is likely to measure. Go hiking and enjoy!

markwarren — Fri, 30 Sep 2011 22:15:29 +0000

Jeff Bezos’ presentation introducing Amazon’s new Kindle Fire reinforced the cornucopia of product lines under the Amazon brand. Without further ado, how about this for their new logo:

full size

Renderings of the New Apple Store at 340 University Ave. in Palo Alto, CA

markwarren — Tue, 02 Aug 2011 00:05:34 +0000

The Palo Alto Weekly’s web site published nice renderings of the new Apple Store to be built on the former site of Z-Gallerie at 340 University Ave.

Plans for Apple's new glass-fronted and topped retail store at 340 University Ave. in downtown Palo Alto are edging closer to final approval. The existing Apple Store is just to the left.

A new Apple retail store is planned for 340 University Ave. in downtown Palo Alto, the former Z Gallerie.

This view of the new building shows what a pedestrian would see from the sidewalk.

Existing Apple Store across the street.

Even More Details About Apple’s Grand Central Store

markwarren — Tue, 26 Jul 2011 00:48:56 +0000

More detail behind the WSJ's rendering of Apple's Grand Central store. View from the NE balcony area toward the E balcony. Credit: Rob Bennett for WSJ.

Mr. Grossman’s Wall Street Journal blog entry about Apple’s new Grand Central Terminal store provides great visuals for the new space. Their proposal began as a response to the MTA’s May 23, 2011 Grand Central Terminal Request for Proposal and that RFP contains quite detailed floor plans, elevations, sign locations and mechanicals for the areas that Apple has proposed to occupy (see pg 32 of 61 for instance).

In RFP Addendum 2, Apple’s questions provide even more suggestions about their proposed modifications. Enjoy!

The new Apple Store turned out just like the renderings!

Update 2: Apple’s store in Grand Central Terminal opened to the public on December 9, 2011 just in time for the holiday shopping season and it looks just like the renderings. Happy Holidays!

Update: Appendix 4 of the RFP links to an entire folder full of architectural, electrical and construction plans.

Click to view slideshow.

Sprint TV Streams ESPN World Cup for Free

markwarren — Sat, 26 Jun 2010 06:50:57 +0000

My new favorite feature on the Sprint Palm Pre has to be the free, live stream of ESPN World Cup coverage included with Sprint TV. Past favorite features include:

Sprint’s Plan

The rest of Sprint TV’s line up
Unlimited data
Free calls to any mobile number (any carrier, not just Sprint!)
Sprint Navigation included for free (it’s better than TomTom, Garmin or Magellan)

Palm’s Hardware

Superb form factor that fit’s great in the hand and pocket (the iPhone, Droid, Evo, etc… are all too big for a regular man’s pocket)
A swappable battery for essentially unlimited talk time
A physical keyboard
Touchstone wireless charging

Palm’s webOS Software

PalmOS emulator to run all of my favorite PalmOS apps (Handy Shopper, Planetarium and more)
The global search box that covers contacts, apps, web addresses, Google, Google Maps and Wikipedia
Synergy which unifies PIM data (email, contacts and calendars) from all of my sources (Outlook, Google, Yahoo, Facebook and more).
Bash shell as root without jailbreaking
True multi-tasking (e.g. Pandora in the background has been there from the start)
Tethering over USB, WiFi and Bluetooth
Mojo development environment (including the Ares online development system)
Over The Air updates (no need to tether the Palm Pre to a computer for updates)
Automatic, free nightly backups over the air.
Free remote-wipe for lost phones

iOS4 (nee iPhoneOS4) addresses some of these competitive challenges, but for now, webOS remains in the lead. The webOS App catalog isn’t yet as full as Apple’s, however, waiving the first year’s fee for developers should help that problem too.

Fixing HotSync Manager 6410 Error – Connection Lost

markwarren — Wed, 05 May 2010 23:34:40 +0000

Fossil Abacus AU5005 Wrist PDA with Palm OS Black

While reviving my long idle Wrist PDA, I ran into HotSync error 6410 – connection lost. Palm’s knowledge base had some suggestions, however, none of their workarounds resolved my problem. Instead, the problem went away by enabling just the “Local USB” connection (and disabling the other “Local”, “Modem”, and “Network” connection types by right clicking on the HotSync menu in the System tray).

Why the iPad Succeeds Where Others Failed…

markwarren — Thu, 15 Apr 2010 01:58:16 +0000

When Apple announced their iPad in January, my initial reaction was skepticism. Why would the iPad succeed where other tablets have failed for the past twenty years? After trying one out, the answers turn out to lie in the iPad operating system named “iPhone OS”. iPhone OS elegantly solves two critical problems that have plagued past tablets:

First, poor on-screen input has cornered tablet computers into the very narrow “stand-up” computing market where people tolerate difficult touchscreen input only because they are forced to work without a place to sit down with a keyboard. Success for tablets was restricted to places such as package delivery, patient care, and inventory management. The iPhone’s on-screen keyboard, however, finally conquered the touchscreen input problem and obsoleted physical keyboards on app-phones. Apple’s expansion of their on-screen keyboard solution onto the larger iPad frees it from the first deficiency of the tablet world.

Hardware presents the second problem. Tablets must remain compact and lightweight for portability, but they must also offer quick response to dynamic computing demands and long battery life for folks as they walk around. Given that Moore’s Law has annually doubled hardware capacity for over forty years, you would expect blindingly fast computers today that run on sunshine. Today’s CPUs are exponentially faster, but my first tablet computer, built nearly two decades ago and sporting a 0.02 GHz “i386 SL microprocessor which [was then] several generations ahead”, starts up and runs about as fast as today’s MS Vista on advanced modern hardware. What happened to all of those Moore’s law advances? Our coercive monopoly software vendor has continuously squandered that wealth of capacity on bloat-ware and left the end-user experience wallowing along at “sluggish”.

Apple’s iPad solved the hardware problem by exploiting this bloat-ware gap. By keeping iPhone OS lean, they unleash the hardware’s real capacity to deliver a superb UI. Apple’s hardware team delivered relatively standard hardware components by today’s metrics, but fortunately for the iPad, standard hardware in 2010 is several thousand times faster than my original tablet and new lithium polymer batteries hold four to six times the energy of their older NiMH and NiCAD brethren. With a great battery life and decades of Moore’s law advances to spend, the software team under Scott Forstall erased the bloat and has delivered an OS where less (code) truly is more (usable). The experience using an iPad is astonishingly engaging and a quantum leap ahead of anything else in the market. Even the fastest x86 computers, oozing GHz and dimming the lights for miles around, cannot throw off the shackles of traditional software to deliver the iPad’s user experience. The larger screen on the iPad delivers a substantively expanded experience.

Apple’s latest offering, despite its modest hardware, leaps at your touch and then quickly gets out of the way and lets you engage directly with your content. The difference between the iPad UI and other tablets is akin to the difference between reaching out with your hand to pick up a toy versus using The Claw to snatch the toy from a vending machine. Using your hand barely registers in your consciousness; you just have the toy. The Claw process from traditional OS’s, however, might occupy your consciousness so much that you risk forgetting about the content all together. The iPad readily evokes comparison with Stephenson’s A Young Lady’s Illustrated Primer or perhaps its actually one of Roddenberry’s Star Trek PADDs that was misdelivered a century early and on the other side of San Francisco. Hopefully other vendors will get the message. The iPad cold boots in under 20 seconds, starts apps seemingly instantly and has access to the largest set of online books (iBooks, Kindle App, Barnes & Noble, Google Books, Wikipedia, etc…) and movies (iTunes, Netflix, YouTube, etc…) ever assembled in on a single device. Oh, and if you need to get some work done, there’s an app for that too. Multitasking arrives this fall.

Watch out horse and buggy monopolies, the automobile has arrived!

Netflix Movie Player Keyboard Shortcuts

markwarren — Tue, 23 Mar 2010 19:29:50 +0000

The Netflix movie player (Silverlight version) implements at least the following keyboard shortcuts:

Space – Toggle Play/Pause
Enter – Toggle Play/Pause
PgUp – Play
PgDn – Pause
F – Full-screen
Esc – Exit full-screen
Shift+Left arrow – Rewind
Shift+Right arrow – Fast Forward
Up arrow - Volume Up
Down arrow - Volume Down
M – Mute toggle

In full-screen mode:

Ctrl+space – Frame forward/backward mode. Ctrl+space pauses the movie and enters key frame mode (aka intra-frame or i-frame mode). The right and left arrow keys then move between key frames.

The following Ctrl+Shift+Alt+* shortcuts (Ctrl+Shift+Option+* in Mac OS X) toggle information displays on/off when the player is NOT in full-screen mode. The displays will remain on, however, if full-screen mode is activated.

Ctrl+Shift+Alt+M – Menu; includes loading custom .dfxp sub-title files
Ctrl+Shift+Alt+C – Codes; frame rate plus other (unknown to me) info. Also makes the other overlays green.
Ctrl+Shift+Alt+D – Display A/V Stats on-screen
Ctrl+Shift+Alt+L – Logging window
Ctrl+Shift+Alt+P – Player Info
Ctrl+Shift+Alt+S – Stream bit rate and manual rate selection

While the Netflix movie player has these keyboard shortcuts; unfortunately, it doesn’t yet respond to Microsoft Windows Media Center remote control events. The netflixhotkeys Auto Hot Key (AHK) script can add more shortcuts if needed, however, AHK doesn’t easily handle all of the MCE events either. If you are, or know, a Netflix developer, native MCE event support would be really cool (sample code).

2010 Winter Olympics Medal Count Per Capita

markwarren — Mon, 01 Mar 2010 07:05:20 +0000

Many Olympic events highlight the accomplishments of an individual athlete and so it seemed only fair to recalculate the “medal count” rankings to account for each nation’s population. The top five are Norway, Austria, Slovenia, Sweden and Switzerland and, without further ado, here are the remaining per capita stats:

Country 	Rank	Gold	Silver	Bronze	Total	Population	Medals per 10M
NORWAY		1	9	8	6	23	  4,769,274	48.23
AUSTRIA		2	4	6	6	16	  8,344,319	19.17
SLOVENIA	3	0	2	1	3	  2,039,400	14.71
SWEDEN		4	5	2	4	11	  9,220,986	11.93
SWITZERLAND	4	6	0	3	9	  7,630,605	11.79
FINLAND		6	0	1	4	5	  5,312,800	 9.41
LATVIA		7	0	2	0	2	  2,266,013	 8.83
CANADA		8	14	7	5	26	 33,311,389	 7.81
ESTONIA		9	0	1	0	1	  1,340,638	 7.46
CZECH REPUBLIC	10	2	0	4	6	  8,344,319	 7.19
CROATIA		11	0	2	1	3	  4,434,189	 6.77
SLOVAKIA	12	1	1	1	3	  5,406,030	 5.55
NETHERLANDS	13	4	1	3	8	 16,443,269	 4.87
GERMANY		14	10	13	7	30	 82,140,043	 3.65
BELARUS		15	1	1	1	3	  9,680,850	 3.10
KOREA		16	6	6	2	14	 48,607,000	 2.88
FRANCE		17	2	3	6	11	 62,048,473	 1.77
POLAND		18	1	3	2	6	 38,122,972	 1.57
AUSTRALIA	19	2	1	0	3	 21,374,000	 1.40
UNITED STATES	20	9	15	13	37	304,059,724	 1.22
RUSSIAN FEDERATION 21	3	5	7	15	141,800,000	 1.06
ITALY		22	1	1	3	5	 59,854,860	 0.84
KAZAKHSTAN	23	0	1	0	1	 15,674,833	 0.64
JAPAN		24	0	3	2	5	127,704,000	 0.39
GREAT BRITAIN	25	1	0	0	1	 61,399,118	 0.16
CHINA		26	5	2	4	11    1,325,639,982	 0.08

(Other formats: html, .csv)

How to Backup and Restore a Palm Desktop User Data Folder

markwarren — Tue, 15 Dec 2009 01:31:34 +0000

During my umpteenth Palm upgrade, I created the following file right inside of my Palm Desktop User Data folder to remind myself of the simple way to backup and restore a Palm Desktop User Data folder (aka Palm OS Desktop) . Hopefully those wiser than I will leave comments explaining problems and improvements in the process below. Helphand’s Not So FAQ’s for the Palm offers very detailed information about reading the individual files within a Palm User Data folder, however, that’s not quite what I want.

restore_instructions.txt (save this file into your Palm User folder):

------->8 8<--------

To backup this Palm User folder simply copy it to backup media somewhere. If Windows file encryption was used, export your public and private keys as well!! Start, Run, Certmgr.msc, Personal, Certificates, right click on cert, All Tasks, Export…, “Yes, export the private key”.

To restore from backup, read through and then follow these steps:

1) Restore this directory from backup. Make sure the
restored files are read-write (especially those in the MemoPad\
directory, such as memopad.dat, otherwise Palm Desktop will default
to creating a new, empty db instead of importing the old data!!).

2) Make a copy of the restored users.dat file from this directory; step 3)
is going to overwrite the one here. (This directory might already
contain a backup of users.dat, but it might be out of date; make
another backup just to be safe).

3) Uninstall and then re-install Palm Desktop selecting the “Custom”
installation type if necessary to point the install to any
non-standard User Data location. The installation will overwrite the
users.dat file in the User Data location. Pre-6 versions of Palm Desktop don’t have an option for a “custom” User Data location. Instead, update HKEY_CURRENT_USER\Software\U.S. Robotics\Pilot Desktop\Core\Path after the installation.

4) Finish the installation skipping the request for an initial device
sync.

5) Right click on Hotsync in the system tray and exit (it holds onto a copy of users.dat too).

6) Replace users.dat with the backup from step 2).

7) Start Palm Desktop to confirm the data has been restored.

------->8 8<--------