Wireless sensor nodes can help monitor conditions the community, in the next state over, or across the globe. These sensors don't have to be complex or expensive to be useful -- even a simple wireless temperature node can be helpful in tracking heat waves, monitoring the heat-island effect in cities, and serving as a warning system for asthma sufferers.
Previously, I've chosen a prototyping platform and 3D printed useful parts to make a sensor node. This post covers planning, assembling, programming, and testing a wireless temperature sensor node for journalism.
It’s gotten so hot (all together now: how hot is it?) that the Australian weather service has added a new color to its heat map which denotes temperatures above 122 degrees Fahrenheit. That’s 50 degrees Celsius, or half the boiling point of water.
This also doesn’t seem like a problem that will disappear in the near future. Climate scientists believe extreme temperatures are only going to be more prevalent. Due to climate change, many parts of the world could experience more extreme high temperatures and fewer extreme low temperatures, with climate models predicting higher maximum temperatures and more heat waves in the future (Easterling et al, 2000).
By some estimates, these heat waves will increase by a factor of 5 to 10 in the next four decades (Barriopedro et al, 2011). Without countermeasures, these high temps could cause “increased adverse health impacts from heat-related mortality, pollution, storm-related fatalities and injuries, and infectious diseases” (Field et all, 2007).
Some might point out that we have a national service that tells us what the temperature is. Election forecasting virtuoso Nate Silver pointed out in his book “The Signal and the Noise” that it’s such a valuable service, in fact, that a multi-billion dollar service industry in weather forecasting has sprung up from the National Weather Service freely sharing its weather data (it should be noted that these services are providing independent forecasts, not simply repackaging NWS data).
In an age where many phones come pre-loaded with weather apps, does it make sense for a publication to have a network of temperature sensors?
Open-source microcontrollers can be very handy for journalists: they can fly a data-gathering drone and control a data-gathering sensor node, among other uses. Previously I wrote how sensor nodes could be useful in a journalism investigation. Now it's time to leave the theory behind, and actually prototype one of these sensor nodes.
As I’ve written before, though, drones simply are remotely piloted aircraft (or watercraft). By themselves, they are not very useful tools. What actually makes them useful is that they are mobile platforms for sensors, which can collect data to guide reportage. Cameras are just one of a multitude of sensors that drones can carry into the sky.
What kind of additional sensors could you use on a drone? It’s probably easier to ask what exactly you want to measure in the environment, and then find a sensor to fit the application.
Lately I've found myself blogging for the International Symposium on Technology and Society, or ISTAS. It's an annual conference sponsored by IEEE (the Institute of Electric and Electronic Engineers), which as its name suggests, focuses on the impact that evolving technologies have on everyday life.
This year's conference will pay special consideration to the future of the smart infrastructure and surveillance:
In a world of smart things like smart lights, smart toilets, smart grids, smart meters, smart roads, and the like, what happens when you have "smart people" (i.e. put sensors on people)?
What do we make of the growing numbers of businesses like department stores and restaurants that prohibit cameras, yet display QR codes that require cameras to read and understand?
It's not just about surveillance, either. Surveillance has a specific meaning, which refers to observing people or objects from an elevated position.That means surveillance is conducted by law enforcements and governments. Sousveillance, on the other hand, means observing or recording from below. When average citizens, as opposed to the government, do the recording, that's sousveillance.
How about droneveillance? Unlike fixed cameras, drones are highly mobile platforms for a variety of remote sensing devices. They're agile, relatively silent (depending on the altitude), and can even fly indoors. They've gotten especially smart at negotiating obstacles and mapping unfamiliar terrain, and they can work as a team to provide comprehensive monitoring.
Let’s say you’re a journalist and you want to record an important event taking place over an extended period, say 12 to 72 hours. Or even a week, or longer. If you want to record the event with video, that’s far too long to expect anyone to watch it in its entirety.
You can, however, record the whole thing and use some kind of time compression in post-production software. But if you’re recording on high definition video, you can only expect to record about four hours on a 32 gigabyte SD card. Even if you manage to capture 12 or 72 hours of high-definition video using a hard drive, it’s going to be hard to work with such a big file.
The solution is time-lapse photography, which simply means taking photos at regular intervals and turning them into individual frames on a video. During hurricane Sandy, a number of news sites and tech-savvy citizens used a time-lapse photography to document the storm's impact on New York City (below). If you’re not in a hurricane-prone area, you can find other weather-related applications for this technique, such as recording a flood-prone area during a storm.
Of course, you could just as easily record important non-weather events, such as big construction projects, or traffic on a bottlenecked road. Compressing these large-scale but slow-moving events into a one or two-minute clip makes for dramatic video.
At its most basic, you only need two things to pull off a time-lapse video. You’ll at least need a camera equipped with an intervalmeter (a fancy way of saying it can be programmed to take photos at regular intervals), and software to turn the photos into videos.
A camera battery will only last so long, though. If you’re hoping to capture an event longer than three hours, you’ll probably have to rig up an external power supply. This power supply can be as simple as a motorcycle battery hooked up to a voltage regulator, or it can be a sophisticated, computer-controlled lithium polymer setup with photovoltaic (solar) cells. Then there’s the matter of finding a memory card of sufficient size, and a mounting solution with sufficient stability.
Simple is better. If you’ve got drone journalism equipment lying around as I do, you likely already have all the requisite components to make a great time-lapse video. The following is a breakdown of my own experiment in time-lapse photography, which you can replicate or modify to suit your own needs.
Earlier this month, the Canadian International Council wrapped up its "Drone Week," which pooled the writings from national policy and technology experts, to help understand how drones could change the air and ground in three different contexts: Kill, Watch, Aid.
Much of this conversation revolved around the proliferation of drones as weapons. As I wrote in my own CIC piece for Opencanada.org, "Drones for Good," given the history of media's relationship with technology, this was only to be expected:
If we’re being dictionary-accurate, though, “drone” merely means an airplane or boat guided remotely. The first drone was invented by Nikola Tesla, who wowed audiences in New York City’s Madison Square Garden with a radio-controlled boat in 1898. His audience, baffled and scared by the demonstration, likely had little or no previous exposure to radio technology. It would be nearly a decade until the first public radio broadcast, a live transmission from the Metropolitan Opera House.
A New York Times reporter asked the question that would dog the technology from that day on: What of the military applications for the tiny electric boat? “You do not see there a wireless torpedo,” Tesla replied, offended by the reporter’s suggestion. “You see there the first of a race of robots, mechanical men who will do the laborious work of the human race."
Combine the public perception of drones with the public perception of the media and journalists, and it's easy to see how drone journalism faces and uphill battle. But, I wrote, limiting domestic drone use would have consequences.
In other news, weather has been particularly miserable for flying drones as of late here in central Illinois.
The cold really isn't the limiting factor here, either. Cold temperatures make it difficult for small gas motors to operate (they rely on glow plugs to ignite the compressed mixture of air and fuel, which requires heat). But lithium polymer batteries are actually fairly resilient to the cold.
The autopilot might be the limiting factor in cold weather, as I'm finding out the ceramic resonator that keeps the autopilot microcontroller in sync can be thrown off by extreme temperatures. However, it's much easier to warm something up than cool something off from an electrical standpoint. Cold isn't fun, but it's not ultimately a deal-breaker.
Wind actually is the biggest problem. It's hard to fly my current fleet of drones in 15mph winds. It's not impossible to fly a drone in that kind of wind, it just requires a bigger drone (an 8 foot wingspan would be nice).
While I'm waiting for the weather to improve, I'm focusing on using drone equipment for other data-gathering applications, and working on drones that I can actually fly indoors. More on that in 2013.
