This project is and will always be Open-Source, meaning you are encouraged to build a sensor yourself! However, you can also purchase an assembled sensor at ribbitnetwork.org.
The sensor uses a wi-fi radio to connect to the internet in order to send sensor data to the Ribbit Network Database and receive Software Updates from the Ribbit team.
The sensor rounds the GPS location that it publishes to the public database. This means that it is not possible to specifically locate the sensor. Additionally, the sensor does not contain or publish any personal data, limiting privacy concerns.
The power cable is 1.5 meters (5 feet) long. An extension cord can easily be added if you need a longer cord.
Atmospheric monitoring from space is an exciting development that has a lot of potential. However, it's not a magic bullet solution. The scientific consensus is that the best option is to develop both technologies that can work together:
Climate tech satellites are the MOST expensive possible solution. For example, NASA's OCO2, cost $467.7 million. Currently, the ground-based frog sensors cost ~250 to build and assemble. At those prices, we could build 1868000 ground-based sensors for the cost of one satellite. And as you'll see in the next bullet point, we need more than one.
- Satellites have only a limited number of measurements that they can take in a day. If you check out the "Approximate usable daily soundings" you can see how many measurements a day a sat can take. Using the OCO2 example again, it can take about 100,000 1.3 × 2.2 km squares a day. At those rates, it's very difficult to measure a meaningful portion of the earth with any frequency. I believe that having real-time constant monitoring of an area is important to help catch peak emission events like a power plant natural gas plant turning on briefly during peak load. It's hard to imagine a cost-effective satellite solution that could provide that.
- Satellites are good to monitor GHG emissions from the major sources, at the macro level. They are less effective to monitor emissions at the hyper-local level due to their lower resolution.
- Finally, the satellite data is awesome, but many of the sensing technologies are still unproven. They need a "truth" dataset to validate that the satellites are producing accurate data. A ground-based network like Ribbit is an excellent complement to a sat network because it can provide that truth!
The concentration of CO2 in the air is measured using a Nondispersive infrared (NDIR) sensor. These sensors are a type of spectroscopic instrument, that is they measure light and how that light interacts with a material at specific wavelengths. In the case of measuring CO2, light at a wavelength in the mid-infrared part of the electromagnetic spectrum is emitted, passes through a small chamber that is open to the outside air, and a detector then measures the intensity of that light. Light at the mid-infrared wavelength of 4.26 μm (4.26 x 10^-6 meters) in particular is absorbed by CO2 molecules. That means that a portion of the emitted light will effectively be blocked by CO2 in the air in proportion to the amount of CO2. The difference between the intensity of the emitted light and the intensity of the detected light can be used to determine the CO2 concentration.