Why Should I Take Environmental
Instrumentation
ATMOS 5050/6050?
• Hands-on instrumentation courses
are increasingly rare in U.S.
environmental programs
• Environmental fields depend on
data and scientists need to know
strengths and limitations of how
that information is obtained
• Some employers are looking for
prospective employees to have
working knowledge of
instrumentation
Environmental Instrumentation
ATMOS 5050/6050
• Format for the course will be more completely
“flipped” with many lectures provided online
and most class time devoted to hands on
laboratory and field experiences.
• Designed so that all students will become
familiar with electronic instrumentation
• Required text is MEASUREMENT METHODS IN
ATMOSPHERIC SCIENCES by Stefan Emeis.
Expected Course Outcomes
After completion of the course, you will have gained
the knowledge and experience to be able to do
the following:
•
State the underlying principles associated with
instrumentation and data acquisition units
•
Develop proficiency integrating instrumentation
to data acquisition units and programming
those units
•
Develop proficiency to use environmental
instrumentation in the laboratory and outdoors
including following defined safety practices and
using electronic equipment individually and as
part of teams
•
Recognize the steps involved in organizing and
conducting scientific research using field
equipment
What is expected of you?
•
•
•
•
•
Come to lab prepared
Conduct labs with spirit of inquiry
Be safe
Be a team player
Learn from each other (several students have
significant experience with instrumentation,
most likely have none)
Lecture/Discussion/Quiz Combo
• Class time is precious – focus on hands-on,
involved, cooperative learning
• Certain concepts are critical to be able to
prepare for, participate in, and complete labs
• These lectures provide core material, the text
is a resource as well
• Lectures discussed briefly and an online quiz
review must be completed typically by the
end of the day
Core Class Lab Activities
• Programming data logger
• Sensor characteristics
• Weather station setup from start to end (Program,
understanding all sensors, Temp, RH, wind, pressure,
siting and analysis)
• Windsonde and quadcopter start to end (data
collection to analysis)
• RPI camera
• Snow
• Electronic circuits
Syllabus
Course Schedule. Note: Campbell Scientific Visit is mandatory, so make schedule arrangements
now!
Jan 12: Course Introduction Lab 1 – Measuring snow depth
Jan 14: Time response discussion. Lab 2-- Time response.
Jan 19: Performance characteristics discussion. Lab 2- Time response cont. If
time allows, start Lab 3- Programming dataloggers
Jan. 21: Safety discussion Lab 3- Programming dataloggers cont.
Jan 26: Meteorological and precipitation sensors discussion. Lab 4-Setting up
a weather station (inside).
Jan 28: Siting discussion Lab 4-Setting up a weather station (inside cont).
Feb 2: Field work: Lab 4- Setting up a weather station (outside).
Feb 4: Electronics and microelectronics discussion. Lab 5- Rasberry pi
camera.
Feb 9: Lab 4 (outside cont): Take down weather station.
Feb 11: Electronic circuits discussion Lab 4- data analysis.
Feb 16: Upper air discussion Lab 6-Quadcopter and windsonde: Windsonde
launch and recovery.
Feb 18: Remote sensors discussion Lab 6 Quadcopter and windsonde flights
(continued).
Feb 23: Lab 6--Quadcopter and windsonde flights (continued).
Feb 25: Lab 6. Quadcopter and windsonde data analysis.
Mar 1: Campbell site visit. Leave campus 12:30 return by 5:30. Online 5050
Final released. 6050. Midterm.
Grades
• For ATMOS 5050: grades be determined from: (1)
class/lab attendance, participation, and following
safety and security procedures (5%) (2) online
assignments (35%); (3) lab assignments (35%);
final exam (25%).
• For ATMOS 6050: grades be determined from: (1)
class/lab attendance, participation, and following
safety and security procedures (5%) (2) pre lab
online assignments (15%); (3) lab assignments
(35%); midterm exam (20%); final project (25%).
Online Lecture 1 (prerecorded by John
Horel)
• http://www.youtube.com/watch?v=yuOHOk2
hYG0&feature=youtu.be
Course Text and Other Resources
Technical: Brock and Richardson Good Mix: Emeis
Down-to-earth: Burt
Canvas Tutorial
Everything you need to do and the due date are listed
in canvas ‘upcoming assignments’
Group Introductions
You will provide more detailed
information about your
background in canvas Survey
due by next class January 14th
For now, just tell your
•Name
•Major (if different than atmos sci)
•Year of study
•Previous experience with
environmental instrumentation
(if any)
•Favorite aspect of environmental
instrumentation (for most of us
it is the data we obtain but
some just love working with
the instruments)
Easy Lab 1—Go out and have fun in
the snow!
(all work will be completed in-class for
this lab; future labs will require out-ofclass time)
Snow Depth
• The sensor measures the distance from the sensor to a
target.
• The sensor works by measuring the time required for
an ultrasonic pulse to travel to and from a target
surface.
• An integrated temperature probe with solar radiation
shield, provides an air temperature measurement for
properly compensating the distance measured.
• An embedded microcontroller calculates a
temperature compensated distance and performs error
checking.
• Both distance and air temperature can be output as an
analog signal between 0 to 2.5 Volts or 0 to 5 Volts.
• Accurate measurement of snow depth poses many
difficult problems
How the Ultrasonic Depth
Sensor Works
• Ultrasonic – sound waves above range
of human hearing in frequency. The
depth sensor operates at a frequency of
50 kilohertz (50,000 cycles)
• Ultrasonic ranging used in a wide
variety of applications including
autofocus cameras, motion detection,
robotics guidance, proximity sensing,
etc
How the Ultrasonic Depth Sensor
Works
• Sends out a short ultrasonic pulse at 50 Khz
• Detects the back pulse
• Compute range from time of back and forth
travel of ultrasonic wave
• Speed of sound in air dependent on
temperature
Specs
• Beamwidth: 22 degrees
• Accuracy: 1 cm or .4 % distance to target
• Resolution: 3 mm ( .12 inches)
cos(θ) = Adjacent / Hypotenuse
The beam width is 22
degrees which means
that the diameter of the
beam will be 39% of the
distance to the target
=
11 degrees is 0.192 radians
11 ⁰
cos(0.192) = a / c
0.982 = 1 m / c
c = 1.019 m
Measure distance to floor
a=1m
a2 + b2 = c2
b2 = 1.04 – 1
b = 0.2 m
c
90 ⁰ 79 ⁰
b = 19 cm
Floor
Lab 1: Snowmetrics Snow Core
Lab 1: Traditional snow core SWE
measurement
• Use hot water to melt down snow rapidly (and
before evaporation occurs)
• Use fact that 1 ml weight of water = 1 cm3 of
volume
Due for next class (Thurs 14 Jan)
• Read course syllabus
• Complete ATMOS 5050/6050 Pre-course
survey (canvas)
• Watch 30 minute online lecture 1 (canvas) also
available as PPT
Topics: source of measurement error, sensor performance, time
response, and intro to CR1000 data logger
• Read Emeis Chapter 1 (pg 1-6)
Additional info on Judd Snow Depth
Sensor
Speed of Sound Varies with T
Ultrasonic Transducer
• The key component of the ultrasonic system is
the transducer. The transducer is first used as a
speaker to transmit an ultrasonic pulse, then it is
used as a microphone to listen for the pulse after
being reflected off a surface.
• An embedded microcontroller calculates a
temperature compensated distance and performs
error checking
• Distance output as an analog signal between 0
and 5 Volts
Example Ultrasonic Transducer
•A transducer is a device that converts a signal in one form of energy
to another
•Here we are converting voltage into “ultrasonic range sounding pulses or vibrations”
and vice versa
Multiple Echo Processing
• Dramatically improves the reliability of
measurements.
• If the difference between the two samples is
greater than 1 centimeter, then the oldest
sample is discarded and another
measurement is made and another
comparison is made. This retry algorithm will
continue up to a maximum of ten times.
Similar to Sonar
• The travel time of Sonar pulses is strongly
dependent on the temperature and the
salinity of the water. Ultrasonic ranging is also
applied for measurement in air for shorter
distances. The travel time in the air is
temperature-dependent.