When precision counts

The New York Times recently compared GPS watches to real-life distances. The watches came up short.

No watch was horrible, but none came within half a mile of reality. I know, I know – this is a first world problem. But bad GPS can be a real problem too.

Does accuracy matter?

I started Roadbud because bad accuracy in other devices got on my nerves. When Nike Plus chip lost track of my footfalls or the GPS teleported me a mile away and back, my run soured. I’d lose my groove and mentally fidget about the gadget. Once that started, I’d think about other annoyances. Is my shoelace loose? Am I wearing too much clothing? Will I chafe?

Poor accuracy yanks me from the flow and puts me in touch with my inner whiner.

Other runners need accuracy for different reasons. One runner I met at Quantified Self joked he’s logging history for his grandchildren. This has a grain of truth for many people – once you start recording your performance, it’s in the permanent record.

Other people just want accurate records for better understanding. Are you getting faster because you’re improving? Or is it just randomness from a flukey readout?

Why isn’t GPS perfect?

GPS listens for radio signals from precise clocks orbiting the earth on satellites, converting different times into distances and triangulating the distances.

The technology is amazing, but it isn’t foolproof. Radio waves get blocked by trees and tall buildings. Sometimes they get bounced around. The GPS math doesn’t provide an exact location – it gives an area instead (this is the blue circle in Google Maps).

On top of this, positions can be sampled far from each other. Each GPS location drinks precious battery juice, so most devices restrict how often updates are computed. This approach literally cuts corners – if you don’t know each corner, extra distances to the corners are ignored.

Why are some devices more accurate?

1. Better antenna Apple’s problems with the iPhone 4 antenna got more press than other manufacturers, but it’s common to the industry. Good signal = good GPS.
2. Extra sources GPS is terrific, but extra sources can help. Wifi or cell tower triangulation and accelerometers, can all improve accuracy.
3. Better chips The GPS chip is responsible for a lot of heavy math. It keeps track of 31 satellites (they each circle the globe, but use different orbits and have slightly different speeds), holds a very accurate clock, computes distance to the satellites, and then calculates position + accuracy. Most chips take mathematical shortcuts to use less battery, but some of the shortcuts are smarter than others.
4. Better post-processing How smart is the device in looking at the position from the chip? Ever snap your positions to a street grid? Computers can use many tricks to pinpoint your location even without a GPS reading.

Is GPS accuracy critical?

Official race distance measures

Accuracy is very important to me, but only one feature in the package. I can improve my accuracy by repeatedly measuring with a Jones counter. But who wants to work so hard for a statistic? I want to run wherever the mood takes me – not a premeasured course.

Too much effort works against my real goal of getting into my groove. Here’s what I need most:

1. Track where, how far, and how fast I run
2. Show me stats on a big display or through my earbuds
3. Don’t force me to use tiny buttons or confusing menus

I care about other stuff too – music, weather, graphing, etc. But most important, don’t mess with my flow.

Is the iPhone better?

Yes and no. I believe the chip and antenna are inferior to some GPS watches. The iPhone uses wifi signals and other improvements, but in a way that makes accuracy worse (to be covered in a future post). No personal experience, but Androids have an even worse reputation.

The iPhone shines in one area: app developers can adjust the location as needed (Roadbud uses fancy math to improve locations, but we need to do more).

Where do you come out?

Some runners were surprised by the NYT article. Some thought it carried a hysterical tone about a non-event.

The truth varies. GPS accuracy varies depending on where and when you run.  And some devices perform better under specific conditions.

What about your GPS – good enough for government work?

Related posts:

1. iPhone running app accuracy – is GPS enough?

More accurate, retina graphics, new Twitter hookup, and lots of user interface smoothness.

Expect lots of little improvements over the next few months.  And then a big one.

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My Governor - too fat to be President?

I love being fit.

I eat my vegetables. I set my alarm far too early so I can fit in a workout. Heck, I built an iPhone app because I found other run trackers annoying.

There’s some nice payback – I sometimes hit the runner’s high and I’ll probably live a bit longer.  I fit into my old clothes and I fancy my wife still finds me attractive.

Meanwhile, America’s getting fat.

The United States is being hit by a true obesity epidemic.  30% of today’s adults are obese and the problem is even worse for the poor.  Obesity isn’t only cosmetic.  It leads to problems like diabetes and heart problems.  Plus, people just feel lousy about their bodies.

We can all see this outside the statistics.  Beaches and restaurants are crowded with the overweight.  Even the local swim teams are rostered with chubby kids.

But heartlessness is a much worse problem.  Most viewers don’t watch The Biggest Loser for inspiration.  One devotee told me she likes “watching the fatties cry”.  We’re just using the health issue as a license for nastiness.

Does ridicule help?

Many people excuse their cruelty by claiming this is needed to change societal attitudes.  Really?  25% of women would prefer severe depression over obesity.  And what fat kid doesn’t already feel ashamed of his body?

The last gubernatorial election in my home state featured a series of TV commercials highlighting one contender’s wobble and jiggle.  The highlight of the campaign was a commercial titled, “Pushing his weight around”.

In the end, the fat guy won and is spoken of as a potential President.  The skinny pol lost.  In a fitting case of “just desserts”, he went on to “misplace” 700 million dollars of other people’s money and looks to be headed toward jail.

Politicians have thick skin.  So the scolds are moving on to target kids.  A series of public service announcements is broadcasting cautionary tales to help children avoid becoming one of the chubbies in the commercials.

There’s something seriously wrong here.  Why are we picking on the fat kids?

There’s too much unhealthy disdain for “those people” gorging toward diabetes and eating themselves into an early grave.  Yes, the overweight lady at KFC would be healthier if she snacked on carrot sticks instead.  But what of it?

We all can find ways to push out a little more life.  Nobody sneers at the fellow commuting to work instead of moving closer to the job.  Or the girl who’d rather bask on a sunny beach with a fun read than squeeze in another workout.  There’s simply more to a well-lived life than skinniness.

There are some good reasons why people are fat.

Unhealthy food makes you feel good (unless you get the McQueasies). Potato chips, ice cream, chocolate cake.  Evolution built us to search for the berry, gorge for the upcoming famine, and cook our way towards extra brainpower.

Treats taste delicious to humans, even in unhealthy amounts.  It’s hard to fault someone for looking for a little enjoyment after a hard day – especially if they’re poor.

George Orwell foresaw this problem 75 years ago in The Road To Wigan Pier:

The ordinary human being would sooner starve than live on brown bread and raw carrots. And the peculiar evil is this, that the less money you have, the less inclined you feel to spend it on wholesome food. A millionaire may enjoy breakfasting off orange juice and Ryvita biscuits; an unemployed man doesn’t.

If you take away scolding, what’s left?

1. Get in better shape yourself.  Obesity is literally epidemic because it spreads among groups.  When your friends grow heavy, you follow them.  But this works in the other direction too.  So grab a running or walking partner and have some fun together.
2. Teach kids fitness.  My 10 year-old’s soccer team amazes me.  These girls happily practice in cold rains or the dead of winter because of their coaches’ love for the sport.
3. Help make inner city streets safer.  Many poor parents reasonably prefer to coop their kids up to keep them safe.  Of course, this makes them fatter.
4. Let kids be kids.  Outside. TV reports have warped our perceptions on safety.  We’re now much safer than thirty years ago, but children are being coddled on playdates, in front of computers and cells, and suffering through structured playtimes.
5. Stop subsidizing factory food.  If people want to eat Fritos, fine.  But why are we shovelling tax dollars towards corn farmers?
6. Look at the positive side.  Seriously.  America is the first society in human history with obese poor people.  Ever.  Simple math tells you once you cure starvation, obesity rises.  This isn’t perfect news, but it’s so much better than starving the poor.

I love being fit.  But I’d much prefer being the guy who wheezes up the stairs than the fellow who is cruel to fat kids.

Do you think I’m off-base here?  Let me know in the comments.

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Beta testing takes flight

Most beta tests have you tapping away at your desk, possibly accompanied by a side of potato chips.  I’m proud to announce a few openings in our beta.  You’ll help us out and also get to work off some of the New Year’s squish.

Beta tests can be very useful – they help software get better because people use apps differently than the designers ever imagined.  I’ve gotten great feedback, funny comments, and cut off annoyances that could hit a wider audience.  The beta testers get their hands on some cool software, but they mostly do it from the kindness of their hearts.  And a desire to make the software world a step less annoying.

The downside is the process.

Every past beta I’ve run Frankensteined its way to life with a pile of bureaucracy.  This one’s better (with the miraculous help of testflightapp.com).  They streamlined the beta test and magically handle:

1. Signing up testers
2. Gathering UDIDs (the secret code on your iPhone that allows us to send you beta software)
3. Over-the-air installs (wondrous!)
4. Asking impromptu questions at any point in the software
5. and much more

We’re almost ready for another software release.  It’s not only because of hard work from the developers, but also because of patient help from testers.  If you want to help us as we layer in more innovation, please sign up at http://bit.ly/uFrUwU

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Four wheels better than two?

I’m not always looking for speed accuracy.

I fondly remember dodging speeding tickets in my post-college Jeep CJ-7. The speedometer read low (honest, officer!) because of the oversized tires. But true mileage is far more important when I run.

Accuracy counts in a running app. Nobody likes missing out on their hard-fought mileage. Worse is grinning over a speedy workout and discovering you got played by a buggy app (this happened to me!).

Speed (and distance) can be measured through many different systems. I won’t trouble you with pitot tubes, but I’m about to get my geek on (I used to be a mechanical engineer). If the gory details bore you, skip to the bottom to find out what’s in version 1.05.

Rotations – how your car works

Rotations measure distance well when calibrated correctly (most people don’t rely on fat tires to flout the law). One app listens for clicks between your spokes and a straw stuck to your front fork (goofy, but it works even on the iPod touch). Too bad nothing rotates during runs or walks.

Accelerometer – how Nike plus works

An accelerometer (tiny chip that senses movement) feels the shock from your steps and multiplies by stride length. Unfortunately, stride length changes during a run. And those freakish cyclists have no stride length at all!

Nike uses a sophisticated formula that measures contact time. This improves accuracy, but is often wrong by 10% and doesn’t map your workout.

GPS satellite orbits

GPS – how Roadbud, Garmin, and Runkeeper work

GPS checks time on atomic clocks orbiting around the earth. It converts this time into distance and then calculates position in three dimensions. That’s the easy part – the Defense Department sweated the details years ago.

Applying GPS to running is a bit more difficult.

• Accuracy depends on listening to a number of satellites in good position. Since the satellites are always moving, sometimes they are too bunched up or just out of sight. The signal can also get blocked or bounced by buildings.
• High accuracy positions are mixed with wide guesses.
• The iPhone tries to “help” GPS by reporting location based on the wifi routers or cell phone towers it hears. A good idea in theory that doesn’t work well in real life. Skyhook Wireless provides this service to Apple and claims higher accuracy than reality – which leads to a lot of ugliness.
• GPS elevations can be wildly inaccurate because the satellites are closer to each other vertically.

Rainy day, precise position

Roadbud (and any other GPS device) has three big jobs:

1. Improve the raw GPS data
2. Determine which positions are legit
3. Combine with other data sources

Correcting GPS is tricky – if you include all the inaccurate positions, the trace jumps all over the map. If you go to the other extreme and drop all the fuzzy positions, you cut out corners and reduce mileage. The magic is in finding the right positions to include.

We’ve created a number of sophisticated methods to improve accuracy – and we’re still adding to the craft.

Here’s what we don’t do:

• Artificially smooth paths (shows a different, incorrect trace)
• Average current speed (takes forever to show correct speed)
• Ask users to turn off wifi (annoying and occasionally cuts out useful data)
• Blame cloud cover (or witches)

Roadbud isn’t perfect, but it works well, even when there aren’t many satellites around. If you ever meet up with an inaccurate run, email your screenshot to support@roadbud.com. We’ll do our best to track down the problem and keep it from happening again.

Related posts:

1. GPS Running Nirvana

Earbuds pipe more than music

I’ll confess. Running bored the hey out of me. The iPod turned my runs upside down – I suddenly rocked along to my own theme music. I ran longer. Even better, I ran regularly.

I’m not the only one. Brunel University compared students running with music vs. students running in silence. Music increased endurance 15 percent.

Still, the best runners I know avoid music. Not sure if they’re worried about safety or if tunes shout “amateur” in the elite world. Either way, I think they might be missing some of the less obvious reasons for tuning in.

1. Spoken stats: Big, clear numbers on your iPhone are terrific, but sometimes you’re pumping too hard to read the info. And squinting at numbers on a watch? Ugh.
2. Safety: Loud music doesn’t mix with situational awareness. But tying into your app means sending a map and calling a friend is only a few clicks away. Just keep the volume reasonable.
3. Podcasts: Serious runners often put so much time into running they need to scrounge for extra minutes. Podcasts allow you to combine runs with lectures, news, running articles – whatever you need to catch up on.

Big numbers if you're looking

When I’m running normal, I like occasionally hearing my pace, distance, distance, etc. Every half mile is the perfect wake-up in case I’ve let myself get distracted. Plus, I love the countdown after my halfway point. My reptilian mind wants to know how much longer before I stop – this just makes it easy.

If I’m training hard, I love hearing my stats over and over. This pushes me up and further. The stats button occupies the upper part of the iPhone, so it’s easy to tap without even looking. My personal need for easily-accessed stats drove Roadbud towards carefully-designed screens and application-level screen locking.

New version 1.04 is at the App Store: Roadbud 1.04 adds a number of improvements. The most important are better audio status, accuracy, and battery life. I’ll get deep into the hows and whys of GPS accuracy in a future blog post.

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Clear numbers while you run

We might have luxuriated in the perfect spring weather outside. Instead, we’ve been plinking away on the keyboard. Our time sweating over a hot compiler paid off.   Roadbud is here to make your run rock!

What’s Roadbud anyway? It’s an iPhone app for runners that measures pace and distance. Roadbud’s built with useful functionality like integrated iPod controls, audio status (in a lovely Glaswegian accent!), screen-lock, and plenty more.

The great big safety button is my favorite feature. My stomach knots up when my wife runs alone. Now she can email me her exact location (and call) with a quick button press.

We’re discovering other uses too. I spoke with a runner last week about “Roadbud 911″. She told me this function was a must-have – her epilepsy is a constant worry. Personally, I’m hoping nobody needs to use the safety button. Extra peace of mind allows runners to move faster.

Features are important, but only if they fit together smoothly. Runners can’t fidget with gizmos during a workout. We’re polishing the app with commando usability tests. I’ll continue to man some local races to watch runners using Roadbud. If you see our table, stop by.

We’re uploading the next version today (longer battery life, spoken status improvements). We’ll keep improving (and you’ll get free updates installed to your iPhone). If you have any ideas or complaints, email support@roadbud.com.

Price: Roadbud Rookie has everything you need to track your run – and it’s free. Roadbud Pro adds audio alerts, safety button, and integrated iPod controls. The Pro version costs $9.99 - less than a single entry fee and hundreds less than some other GPS devices. To celebrate our launch, we’re charging only $0.99 (today only).

If you like Roadbud, spread the love. Get the word out on twitter, email, or just tell your running friends.

Related posts:

1. Roadbud version 1.0 launch slip
2. Testing Roadbud in a drenchquake

Earbuds up close

Silly question:
Ever have a problem with earbuds falling out while you run?

Met up with local runners last week at the Cherry Blossom Festival in Newark. One fellow mentioned his quest for the perfect headphones – because of the annoyance of earbuds dropping out.

I’ve been vexed by the same indignation. One moment, your legs are effortlessly pushing out the miles and your head is pleasantly thumping to Macy Gray. Suddenly an earbud is dangling with hopes of pulling out the other side.

The hipster silhouettes on iPod commercials never suffer this problem.

Strangely, this appears to be a common problem – there’s even a dorky earbud leash to catch your earbuds when they inevitably fall out.

Some days the earphones fit fine and didn’t ever fall out. Other times, the buds had Mexican jumping beans inside – just waiting to bounce around. Do my ears shrink on very cold days? Pretty baffling.

I experimented with many ideas – I subdued the buds with a knit cap.  I twisted the buds into different positions. I even used the squishy earbuds that go in your ear canal (yuck!).

Then I finally read the subtle grey lettering on the buds – “L” and “R”. I’d always ignored left/right (stereo either way, no?). However, Apple builds the buds off-center – each is designed for one ear.

I tried placing the left bud in my left ear. Works like a charm – I’ve never dropped a bud again.

Lesson learned: I might need to invest in a speed reading course – took me months to read two letters.

Update: some readers comment that they’ve tried my left/right trick and it didn’t work for them. If you’re having this problem, left/right works for some (me, for one) – but not everyone.

Related posts:

1. Why run with headphones?

The world awaits your ears

I used to have a big problem running – sheer boredom stopped me before I worked up a sweat. The iPod was heaven sent for my personal enjoyment. I stopped grinding through my runs and began grooving.

No more restless mind telling me to stop. Just a little Miles Davis as I cruise along the river. By the time my legs realized I was running, I’d travelled a half mile down the road and was ready for more.

Music has been terrific for me, but I bumped into a podcast (regularly updated audio content) of a guest article I wrote on A Smart Bear.

Never really messed with podcasts before, but I took a flyer. I downloaded a few “blog articles” about software startups to my iPhone (simple – didn’t even need wires) and went for a run. I also took along RunRunLive (a fun running podcast with music, interviews, and lots of running talk.

Turns out, podcasts are wonderful. If you’ve ever been forced to web-surf instead of taking the time to really consider a deep article, this is for you. Plus, it keeps your mind off the pain.

RunRunLive was great in a different way. Chris (the host) is a hoot – he throws his own music among the interview clips and corny jokes. His podcast feels like a chatty running partner (which I sometimes really like).

Podcasts in my playlist

Download a podcast without wires

1. Tap the Itunes app
2. Search for podcast (Example:  ”RunRunLive”)
3. Press “FREE” and then “DOWNLOAD”
4. After the podcast finishes downloading, tap the iPod app
5. Select Playlists
6. Select On-The-Go (will get easier in upcoming iPhone OS)
7. Add the new podcasts to On-The-Go

Tip: I like listening to smart startup talk like A Smart Bear and Bob Walsh. But hearablog.com is happy to add more runner-friendly blogs. Let me know if there’s a running blog you want to hear. I’ll pass it on (I already asked for Mark’s Daily Apple).

What do you listen to? Let me know in the comments.

Related posts:

1. Workout hack 6 – great music

Dead tree up the street, no one hurt

We’re shipping Roadbud to the App Store today (thanks Alex and Vlad!).

Expect a few days for the approval process and then we go live.

—

This weekend’s weather was almost malevolently aimed at stopping development. The developers were still recovering from a Siberian blizzard when massive rains hit New Jersey.

50 mph winds pushing six inches of rain creates a lot of havoc. I was literally running in this mess, testing the GPS functionality in Roadbud. I heard lots of sirens, but had no idea the storm was serious enough to kill six people. My friend’s family was marooned on a train for six hours – with kids.

Running trail - river is .25 mile away

I was only slightly dampened, thanks to my Marmot raingear. Demonstrating Roadbud’s location-positioning was worth a little soaking. I believe we’re more accurate than any commercial device – and we will unsleeve more GPS tricks.

Accuracy matters because crazy Nike+/running app speeds distract me from running flow.

—

Testing Roadbud in a deadly storm is not my idea of sprezzatura. But it was fun anyhow and an experience I will certainly remember.

We made a great running app that will fire up your run. We’ll add screenshots to the website and detail the new safety feature in a few days – when Roadbud goes on sale in the App Store.

We can use your help:

• Tell us what you need in Roadbud
• Email or twitter your friends to sign up for launch notice – they’ll get 90% off for one day.

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