3 ms·

I'm a cofounder of Tule and happy to answer any questions. A few corrections for the technical crowd: This technology hasn't existed since the 1800's. It is d

by jefflab 12y ago

I'm a cofounder of Tule and happy to answer any questions. A few corrections for the technical crowd: This technology hasn't existed since the 1800's. It is derived from a technology called Surface Renewal that measures the turbulent transport of mass and energy from the planetary surface to the atmosphere. The concepts behind Surface Renewal were first developed in the 1930s by chemical engineers. These chemical engineers developed a model to describe the movement of gases into liquid media by fluid volumes interacting with the air-liquid interface. In the 1990s, UC Davis researchers adapted the Surface Renewal concept to the planetary surface-to-atmosphere interface. Recent improvements in the technology enable Tule to measure the amount of water vapor carried away from crop field by wind eddies. Our technology was validated for accuracy against the gold standard research tools used in academia, lysimetry and eddy covariance. What truly makes our technology exciting is that we can tell farmers the optimal amount of water to apply to maximize plant growth (yield) and plant stress (quality). Studies have shown that getting irrigation right can radically change yield and quality. Before our technology, farmers have never had the feedback to optimize irrigation. This is analogous to NewRelic locating the bottlenecks in your server performance. You can't optimize until you can measure. edit: As requested, here are links to the technology: An easy to read summary is here: http://edu-tuletechnologies-com.s3.amazonaws.com/Tule_Surface_Renewal_Background.pdf http://edu-tuletechnologies-com.s3.amazonaws.com/Tule_Surfac... The original academic paper is here: http://myweb.ecu.edu/suh/PawU1995.pdf http://myweb.ecu.edu/suh/PawU1995.pdf

nkurz 12y ago
That wasn't at all the sort of technique I was expecting. Without knowing otherwise, I'd presumed that you were doing something that directly measured evaporation rate, and that the claim that it was covering a large area instead of a single point was just puffery based on the the hope that air conditions were constant over the whole area. This is much better. I only glanced at the original paper, but I was lost by the end of the first sentence: "Numerous methods exist for estimating the flux density of scalars." Mathematically, that doesn't make much sense. Does scalar have a different definition in meteorology? Or is this an odd translation from another language?
- tmshapland 12y ago
  Obviously I am unaccustomed to the waters of Hacker News. I meant to post this in response to nkurz's question rather than the main thread. See below. Hi, I'm Tom, the other cofounder at Tule. I developed the recent improvements in Surface Renewal during my PhD work at UC Davis. Examples of scalars, as the term is used in atmospheric science, are air temperature, water vapor concentration, carbon dioxide concentration, or any other constituent of the atmosphere. Here is a more formal definition from http://glossary.ametsoc.org/wiki/Scalar http://glossary.ametsoc.org/wiki/Scalar: Any physical quantity with a field that can be described by a single numerical value at each point in space. A scalar quantity is distinguished from a vector quantity by the fact that a scalar quantity possesses only magnitude, whereas a vector quantity possesses both magnitude and direction. Thus, pressure is a scalar quantity and velocity is a vector quantity.
andymoe 12y ago
Neat stuff! I don't know much about how your sensor communicates... wifi or cell maybe. But if you happen to be using 915MHz ISM band for anything we make a little $99 MFi accessory for iOS designed for drones you might be interested in playing with. Feel free to ping me.

by jefflab 12y ago

nkurz 12y ago

That wasn't at all the sort of technique I was expecting. Without knowing otherwise, I'd presumed that you were doing something that directly measured evaporation rate, and that the claim that it was covering a large area instead of a single point was just puffery based on the the hope that air conditions were constant over the whole area. This is much better. I only glanced at the original paper, but I was lost by the end of the first sentence: "Numerous methods exist for estimating the flux density of scalars." Mathematically, that doesn't make much sense. Does scalar have a different definition in meteorology? Or is this an odd translation from another language?

tmshapland 12y ago
Obviously I am unaccustomed to the waters of Hacker News. I meant to post this in response to nkurz's question rather than the main thread. See below. Hi, I'm Tom, the other cofounder at Tule. I developed the recent improvements in Surface Renewal during my PhD work at UC Davis. Examples of scalars, as the term is used in atmospheric science, are air temperature, water vapor concentration, carbon dioxide concentration, or any other constituent of the atmosphere. Here is a more formal definition from http://glossary.ametsoc.org/wiki/Scalar http://glossary.ametsoc.org/wiki/Scalar: Any physical quantity with a field that can be described by a single numerical value at each point in space. A scalar quantity is distinguished from a vector quantity by the fact that a scalar quantity possesses only magnitude, whereas a vector quantity possesses both magnitude and direction. Thus, pressure is a scalar quantity and velocity is a vector quantity.

andymoe 12y ago

Neat stuff! I don't know much about how your sensor communicates... wifi or cell maybe. But if you happen to be using 915MHz ISM band for anything we make a little $99 MFi accessory for iOS designed for drones you might be interested in playing with. Feel free to ping me.