Couldn’t make it to Jack Dangermond’s #EsriUC 2017 keynote? Read this.
To say that Jack Dangermond is the Steve Jobs of the geographic information systems (GIS) industry would be a bit unfair. After all, when was there ever a time when Apple commanded 43% market share in its domain?
Jack Dangermond is an innovator par excellence, the Godfather of spatial analytics, the founder of Esri – the world’s biggest GIS software company. Jack Dangermond is the reason why the sprawling San Diego Convention Center has been buzzing like a beehive since Monday morning; the reason why more than 17,000 geo-geeks have travelled from over 130 countries to assemble at one place; the reason why city Mayor Kevin Falconer felt compelled to declare July 10 as the ‘Esri User Conference Day’.
The annual Esri User Conference, the Mecca for GIS professionals, is in its 38th year now, and Jack in his 71st. As the conference gets bigger with each passing year, its creator also shows no signs of slowing down. His eyes still twinkle with the curiosity of a teenager; his infectious energy palpable. The man commands respect without even speaking a word.
But when he does speak, you hang on to each phrase like a memory. His hands do as much talking as his lips – did we mention the electric energy already? “The purpose of this meeting is to be together, to grow together. Learn from each other. Share what we’re doing. To become friends. Have a little fun from time to time. And the theme: The Science of Where…” The loyal congregation listens with rapt attention. “Your backgrounds are rich. You come from almost every field of human endeavor. You are special people in my opinion. You hold the reigns of a better future.”
A better future is exactly what Jack envisions with the Science of Where – the science of geography and the technology of GIS – a science has become even more important in a world plagued by population explosion, climate change, and social conflict.
Jack realizes that to address these issues, we first need to understand them better. “Our world is undergoing a massive digital transformation. We are automating everything and measuring everything that moves and changes, and are wiring it together in a fabric across the planet. The Science of Where is a fundamental digital language about understanding. GIS provides us a language and framework to organize maps and data to visualize and analyze shapes and patterns. We can make decisions and take those into action.”
For Jack, GIS is a system of engagement. It is a system of insight. It approaches problem-solving in a holistic way because it integrates people and processes. “Using the Power of Where we are integrating everything,” he says. And advances in technology like distributed computing and deep learning will only expand our ability to apply GIS everywhere. “Web GIS is the modern GIS architecture. It’s helping you do your work better. It’s leveraging web services to integrate teams with the shared knowledge to improve collaboration. It brings all types of data together: imagery, maps, real-time data, 3D…”
Jack believes that the complexity of our cities is being modeled by the Internet of Things, with real-time information applied to do space-time analysis in meaningful ways. “We are extending the reach and bringing the power of maps to everyone, across organizations and beyond,” he stresses.
This, Jack avers, is being done through smart mapping – using computation and analysis to automate the creation of maps. “Web GIS is revolutionizing how we plan and design, integrating science into the design process. We can do interactive designs, and look at different scenarios, to collaborate on good designs.”
Collaboration is actually the buzzword at Esri right now. The company is improving geocoding by crafting new tools for CAD integration with Autodesk. It is teaming up with DigitalGlobe to offer the latter’s high-resolution satellite imagery and image analysis on the fly. Jack also reports progress on integration with the Adobe Creative Cloud, so graphic designers can get more productivity out. ArcGIS content is also set to receive Sentinel imagery, apart from the Landsat data.
The road ahead also looks rich for ArcGIS. Jack promises to provide more and more improvements with releases every six months or so. “We have hundreds of developers focused on what you want them to do and work on. This is what makes us excited.”
As he sums up, Jack quotes Leonardo da Vinci from notes scribbled on the palm of his hand: Knowing is not enough, we must apply. Being willing is not enough, we must do.
And do we must, for a better future.
How accurate is the altimeter in a GPS watch?
If you’re an outdoorsy person, you’d know there are quite a few sports like hiking, climbing, skiing, and skydiving, where knowing the altitude or the elevation of a place not only satisfies your inherent curiosity, it is, in fact, imperative for your safety.
If you’re an outdoorsy person who likes these sports, chances are you own a GPS watch with a built-in altimeter – an instrument that measures your height above a fixed level, usually adjusted for the mean sea level.
If you’re an outdoorsy person who likes these sports and owns a GPS watch with a built-in altimeter, there has probably been a time when you’ve seen the device giving you some pretty erratic altitude data. Ever wondered why? To figure this out, you first need to understand how an altimeter watch works.
Traditional altimeter watches
Traditional altimeter watches use atmospheric pressure as a gauge to measure and track changes in the altitude – just like a barometer. The atmospheric pressure is greatest near the earth’s surface because gravity pulls everything, even air molecules, toward it. As you go up, the pressure starts to decrease, and the altimeter compares this new pressure to the previously-known sea level to determine your height.
But altitude is not the only factor that causes variations in pressure; weather changes do too (high temperature = pressure drop, and vice versa). So, to get an accurate reading, a traditional barometric altimeter watch would need to be calibrated almost on a daily basis to match the known reference height. This can easily be done using Google Earth: Just search for your exact location and note down the elevation mentioned at the bottom of the page.
GPS-based altimeter watches
On the other hand, an altimeter that uses the Global Positioning System to determine the altitude draws on the signals from GPS satellites (and sometimes GLONASS), pretty much in the same manner as positioning technology. While a GPS receiver needs to triangulate signals from three or more satellites to pinpoint its exact position, signals from at least four satellites are essential to calculate the elevation. And to achieve any kind of reasonable accuracy, at least one of these satellites need to be directly overhead the receiver.
Though this condition is not exactly hard to fulfill with 31 functional GPS satellites orbiting the Earth right now, discrepancies crop up because the speed at which radio waves travel gets affected by the variations in the density of the ionosphere. The general rule of the thumb is that vertical error is three times the horizontal error. If a decent signal reception is available, a modern GPS receiver should be able to give elevation data accurate to a range of 10 to 20 meters (35 to 70 feet) post correction.
And that’s exactly where the problem with GPS-based altimeter watches meant for the great outdoors lies. The GPS reception isn’t always terrific and hikers have reportedly found the altitude measurements to be off by as much as 400 feet!
Garmin confirms this, explaining that the main source of error has to do with the arrangement of the satellite configurations during fix determinations. “The earth blocks out satellites needed to get a good quality vertical measurement. Once the vertical datum is taken into account, the accuracy permitted by geometry considerations remains less than that of horizontal positions.” As such, the values provided by GPS-based altimeters should be used with caution when navigating.
So, while it’s obvious that both systems have their pros and cons, if you’re looking for an accurate elevation data (and a way to ensure you don’t get caught in a white-out storm), you would be better off if your GPS watch uses a barometric altimeter as a system of checks and balances.