Information
Welcome!
Click on any instrument on the diagram to display its information here.
Met One Three Cup Anemometer
This anemometer is located at 10 meters, the meteorological standard height for measuring wind speed and direction.
Optical Rain Sensor
The Hydreon RG-11 optical rain gauge can detect a single drop of rain, down to one ten-thousandth of an inch. That can be used to close windows to protect equipment, like telescopes, that can be damaged by rain. It will also function as an optical rain gauge, similar to a tipping bucket. It uses the same technology that some automobiles use to detect rain and turn on the windshield wipers.
Inspeed Wind Vane
This sensor determines wind direction.
Sky Temperature and Lux
One sensor monitors the light level in lux. That helps discriminate between cloudy or clear days, as well as the cloud density. An infrared sensor is aimed vertically to measure the sky temperature. It also measures the cloud temperature and helps determine the presence of clouds and their relative density.
Hail Sensor
The hail sensor is located at the top of the tower. It consists of a stainless steel pot lid with piezo microphones glued to the surface. When hit by hail a distinctive ping will be detected.
Peet Bros Three Cup Anemometer
One anemometer is at approximately 10 meters height, the meteorological standard for wind speed and direction. Another is located at the ten foot level. The idea is to compare the two to see how much, if any, difference there is between the two. If there is a difference, how much is it? If not substantial, lower cost ten foot weather towers might suffice, for practical purposes.
Air Temperature Non-Aspirated
These instruments have temperature sensors embedded inside white plastic plates that reflect the sunlight while allowing air to flow through similar to
these.
Since there is no active element, like a fan, to draw air over the sensor they are referred to as non-aspirated.
Tower Sway Sensor
This sensor is located at the top of the tower. It consists of a 3-axis accelerometer. It is intended to provide information on the stresses the tower experiences that could cause it to sway. These are related to winds, especially high winds.
Optical Lightning Detectors
There are five optical sensors aimed north, west, east, south, and directly overhead. They detect flashes of light and note the intensity and time. Also included is a fast acting transient sensor sensitive in the ultraviolet. Lightning produces a flash of UV light, although its intensity falls off quickly as a function of distance. If a pulse is detected by the sensor it would indicate a nearby lightning flash.
Arbcam
The Arbcam is a webcam pointed south from the tower over highway 19 toward the Carleton campus.
LoRa Antenna
LoRa is a low power, low data rate but very long distance communications system. It is typically used to connect sensors and other devices that produce low amounts of data. Those devices could even be on animals or people. An application might be install solar powered crop and soil sensors in a farm field and monitor from a home computer. Given there are gateways all over the country, it is possible to geolocate a LoRa device, such as one on an animal.
Omni-Directional WiFi Antenna
This antenna provides limited WiFi coverage intended for the biology research space in the Arb.
Internet Link Antenna
This antenna was the original link to the tower. It will be repurposed to extend the range of WiFi further to the north of the tower.
Triaxial Magnetometer
This sensor uses a MicroMag3 sensor (now obsolete) to measure the magnetic field over a range of +/- 1100 micro-Tesla. This monitors the earth’s magnetic field as well as detecting the magnetic pulse generated by a bolt of lightning.
Fluxgate Triaxial Magnetometer
This sensor uses three single axis FG Sensors magnetometers
to measure the magnetic field in xyz. They have coils around them to null out the earth’s magnetic field so they are only sensitive to changes outside of the earth’s field. Typical detections should be due to lighting bolts. Measuring in three dimensions helps locate the direction of the bolt.
Lightning Detection and Ranging
The detection and ranging system is built around the Skyscan P5 lighting detector. This device provides distances to lightning strokes in ranges of 0-3 miles, 3-8 miles, 8-20 miles, and 20-40 miles. It can also identify a lightning pattern as indicative of a severe storm and send an alarm.
Black Globe Heat Stress Sensor
This sensor is used to help determine the effect of sunlight to create heat stress on the body.
The result of that determination can inform coaches to the degree of outdoor activity that should take place and for how long.
It can also alert livestock owners to be sure their animals have adequate water and shade.
The sensor is made using a copper globe, painted black, with a temperature sensor probe injected to the interior of the globe.
More information about the black globe sensor and its application can be found
here .
PAR Sensor
This Apogee Instruments
sensor measures the photosynthetically active radiation level.
This is the part of the spectrum of interest for agriculture, covering the spectrum from 400 nm to 700 nm.
This is what full-spectrum growth lamps provide as it mimics natural sunlight.
UV Sensor
This Apogee Instrument measures the ultraviolet spectrum UVA and UVB with a little UVC, from 250 nm to 400 nm. UVA penetrates the skin and causes aging and wrinkles. UVB affects the outer layer and causes sunburn.
Pyranometer Sensor
This Apogee Instruments sensor measures a broad swath of the solar spectrum, from UV to IR. This is the majority of the shortwave radiation.
Top Section DAQ and MUX box
Data Acquisition and Multiplexer box, collecting and organizing sensor data from the top section.
Leaf Wetness Sensors
Two types of sensors are used to mimic plant leaves to measure moisture that forms on a leaf. The Phytos 31
(formerly Decagon) sensor and the Spectrum leaf wetness sensor
provide a value from 0 - 15 related to the wetness level on the leaf. Levels above are considered wet.
The wetness level is used for disease control (blight or rust), irrigation, pests as some do better in moist conditions, and frost protection.
IR Ground Temperature Sensor
Measures ground surface temperature using infrared radiation.
PurpleAir Particle Detector
PurpleAir sensors are part of a national network to monitor air particles of size PM2.5.
The data is sent to the PurpleAir cloud based network for anyone to see.
Geiger Tube Background Radiation Monitor
Detects and measures the background radiation levels.
This uses the Russian MC-6 gamma-selective tube.
Typical background counts are in the range of 80 to 120. During thunderstorms the rate increases closer to 200 counts per minute.
Air Temperature Non-Aspirated (2)
These instruments have temperature sensors embedded inside white plastic plates that reflect the sunlight while allowing air to flow through similar to
these.
Since there is no active element, like a fan, to draw air over the sensor they are referred to as non-aspirated.
Weather Sensor AIO 2 Sonic
This sensor provides multiple measurements of weather data.
Wind speed and direction are measured with ultrasonic technology.
Basically, the wind affects the movement of the ultrasonic (above human hearing levels) sound wave pulses,
either increasing or decreasing the time the pulse is emitted to the time it is received.
Doing this in two dimensions allows both wind speed and direction to be calculated with no moving parts.
The sensor has a built in compass to determine direction regardless of the orientation of the sensor.
Temperature, humidity, and barometric pressure are also measured.
The Hukseflux solar radiation sensor will be monitored by this instrument.
This instrument is mounted nine feet above ground to monitor conditions at a human level.
Met One is a premier weather instrument company, and this instrument provides reference grade accuracy.
See this link for the manufacturer's information on this instrument.
Peet Bros Three Cup Anemometer (2)
Another Peet Bros anemometer for wind speed measurement.
Air Temperature Non-Aspirated (3)
These instruments have temperature sensors embedded inside white plastic plates that reflect the sunlight while allowing air to flow through similar to
these.
Since there is no active element, like a fan, to draw air over the sensor they are referred to as non-aspirated.
Vortex Wind Speed Sensor
Three cup anemometer made by
Vortex
to measure wind speed at about the six foot level.
Barometric Pressure Heads
Sensors for measuring atmospheric pressure.
Ultrasonic Snow Depth Sensor
The Maxbotix MB7360 ultrasonic sensor sends a 42 KHz ping that is reflected off the snow and the round trip time measured. From that the distance to the snow is measured and subtracted from the distance if there was no snow.
IR Snow Depth Sensor
The Sharp GP2Y0A02YK0F sensor measures the snow depth optically by relating the infrared light reflected from the snow to distance.
8” Tipping Bucket Rain Gauge
"The TR-525USW Tipping Bucket Rain Gauge,
manufactured by Texas Electronics, Inc.,
collects water through the 8" opening and funnels it to a dual sided tipping bucket.
This bucket is balanced on a pivot at its midpoint.
After water fills one bucket it tips down emptying the water that bucket side collected.
When it tips over, a switch is momentarily closed indicating collection of .01" of rainfall.
This brings the other side's empty bucket under the funnel and the process repeats.
This tipping bucket is designed to meet the National Weather Service's requirements for rainfall measurement.
It is the same one that is used by the US Geological Survey at the Second Street Bridge.
RTD Temperature Sensor
Resistance Temperature Detector for precise temperature measurements.
Humidity Sensor
Measures relative humidity in the air.
Fan Aspirated Quad Sun Shield
The standard for ground temperature is measured at a height of 48 to 72 inches above a grassy surface. This sensor is located 60 inches from ground level. The temperature sensor is an RTD (Resistance Temperature Detector) located inside three concentric aluminum shields covered by an inverted aluminum bowl. Air is drawn in over the shields by a fan and exhausted 72 inches away from the intake. The outer bowl is warmer than the first shield which is warmer than the second which is warmer than the third. By the time the air is drawn into the third shield where the temperature sensor is located it represents the actual air temperature unaffected by sunlight’s impact on the sensor.
IR Ground Temperature Sensor (2)
Second infrared sensor for ground temperature.
Hukseflux Solar Radiation Sensor
The Hukseflux LP02 solar radiation sensor measures the solar radiation over a plane surface, a 180 degree field of view. The radiation is expressed in W/m^2. This information is of value to those who use solar panels. This complies with the second class (first class is best) ISO 9060 standard. (ISO is the International Organization for Standardization.)
Soil Heat Flux
Measures the flow of heat through the soil.
The polarity indicates whether heat is flowing deeper into the soil in the summer or out of the soil as it cools in the winter.
The sensor is similar to this one.
Temperature (at and below ground)
A series of temperature sensors are mounted to a pvc tube that is buried underground.
A section of the tube also sticks above ground.
The above ground readings may give a crude estimation of snow depth, while the underground sensors can monitor the frost line.
Below Ground Moisture Sensors
A Hydrascout soil moisture probe is inserted to a depth of approximately 18 inches underground. It provides a number relative to the percent of soil moisture.