Precision Farming

Precision farming

proper and efficient management of a specific unit of area or space

Tools of trade

Global Positioning System (GPS)

Geographical Information System (GIS)

Yield Monitoring

Remote Sensing

Variable Rate technology

Spacial variability

Distance and depth

Temporal variability

Measure of how in this specific area year to year changes causes variability

Causes of Spatial Variability

Soil Type, Topography, Biology, Fertilizer, Tillage, Crop

Georeferenced Data

Data which has coordinates (location) includes GPS(accuracy) and GIS(data layers & prescription maps)

Spatial Variability; Lateral Variability

variability as you move across the plot

Spatial Variability; Vertical Variability

Variability as you move through the soil horizons

Temporal Variability

Minute to minute, day to day, week to week…

Global Navigation Satellite Systems (GNSS)

GPS (US)

GLONASS (Russia)

EGNOS (European) - GALILEO

BeiDou (China)

IRNSS (India)

QZSS (Japan)

History; 1978 & 1995

4 satellites launched system in April, GPS needed to identify location no matter where you are

Space Segment

31 satellite vehicles and 6 orbital plains, 5-8 satellites visible from any point on Earth

S Band Antenna

Collects information and is the control center telling satellite to change time or move

L Band Antenna

communicates to our devices and determines where you are

Position Based on Time

ex: T+3 = 3 times the speed of light

Oscillation Frequency in Atomic Clock

Counts number of oscillation that is removed

Trilateration

method of determining a location by measuring distances to at least 3 known points

Signal interference

Orbital Error

Clock Errors

Atmospheric Errors

Multipath Errors

Receiver Errors

Control Segments

Helps control control clock and orbital errors, Clocks need to be in sync = 4 satellites

Atmospheric refraction

Delays satellite signal

Troposphere

lowest layer of the earths atmosphere

Ionosphere

Can delay signal as it passes through and slows down signal

Multipath Error

Surface that reflect or block a signal (metal buildings and water)

Receiver Errors

Correction

single frequency

dual frequency

Differential Correction (DGPS)

Simplest form of correction use of base station and its location (the closer to the base the more accurate)

Wide Area Augmentation System (WAAS)

developed for airplanes, satellites placed at a higher elevation

Private WAAS

Omnistar, swift, navcon

NASA and RTK

To prove theory of relativity

Real time kinematic (RTK)

Relies on FM signals from base station and is accurate

2 Clock analogy; Pseudo random code

hidden inside L band, knows what time it is

2 clock analogy; carrier signal(millisecond)

repeats way quicker every .365 microseconds

Autonomous Tractors

ProTrakker, electric tractor, driverless tractor

Precision Guidance

Driving in a straight line

Guidance system adoption

Fastest acceptance levels for large acreage

Evolution of auto guidance; lightbar guidance

green lights in the middle if off by 3ft then 3 red lights and steer again 2ft off shows 1 green and 1 red

Accuracy

WAAS<RTK

User supplied base station

Located on a designated location transmitting signals via AM,PM, or cellular signal (size of are depends on signal strength)

RTK clusters and networks

maintained by John Deere with 30 RTK towers tells us which tower is closer for mor accuracy

Evolution of the Auto-Steer

direct attachment to the hydraulic system, the knob on the actual working wheel

Roll-pitch-yaw

need minimum of 2 to detect

Roll

change in elevation between left and right side and works against gravity (roll & pitch or roll and yaw)

Pitch

change in elevation of front and rear wheels (down or up hill)

Yaw

sliding action related to pitch moving left or right

Terrain compensation sensors

inertial sensors, integrated GPS/GNSS receivers detecting roll, pitch, yaw (like the starfire)

Degraded position

loss of satellite or radio signal, signal gained again back to a straight line

Driverless tractor system; supervised autonomy

diver would observe and the tractor would drive on its own (Cse IH and John Deere)

Driverless tractor system; fully automated

could function without control of farmer (Kinze and Fendt)

Implement guidance; Passive Guidance

Trimble- true tracker and John Deere -iguide tracker does everything

Implement guidance; Active guidance

Autofarm-AFTracker, Sunco-acura track, Orthman- GPS ready tracker

Controlled traffic farming

CTF requires: technology equipment and organization

Random traffic farming

soil compaction- random amounts at different parts of area

RTK vs CTF

Following possible paths - Driving in portion of field once taking a large amount of weight  

Lower yield due to compaction  

Controlled  - Driven in set path and not allowed to leave

Benefits of CTF

Lower energy, lower machinery investment, better seedbeds, improved crop yields

Soil sampling

evaluating soil properties and determining fertility

Grid Sampling

simple concept, Can still composite it and average or can take a grid sample point and keep as individual

Advantages: no field history needed, minimum skill level

disadvantages: no justification for grid sizes

Directed sampling

requires more info on the field

Advantages: reduced time and labor and more economical

Disadvantages: Higher skill level required and field knowledge

Interpolation

Uses known soil property data from sampled location to estimate values of upsampled locations

Automated soil sampling

To capitalize on higher density soil sampling several companies have developed machines to simplify the job

Falcon soil sampling  

Agrobotics autoprobe  

Wintex 1000 soil sampler

On the go soil sensor

Electrical and electromagnetic (correlated to soil parameters

Optical and radiometric (differences in absorption)

Electrochemical sensors (taking soil pH)

Mechanical sensors (measures force)

Pneumatic (injected air)

Acoustic (sound waves)

Geonics EM38

electromagnetic inducing based soil sensing

Veris Cart

Measures electrical conductivity data readout and correlated crop response

Veris VIS-NIR

visible and near-infrared reflectance, correlate to important soil properties

Near Infrared reluctance (NIR)

measurement of energy that is reflected or emitted from objects correlation between soil characteristics

Yield monitoring

Sensors mounted on a combine measuring; Methods to calculate yield and moisture and combine into a yield map

Yield mapping

fast feedback on nutrients, moisture, pest pressures like a report card

Plot yield monitors

small plot harvest very precise information and a better system

Components of yield monitors

flow sensor, moisture sensor, ground speed sensor, header position switch, processor/display console

Mass flow

Used more, How much grain being flung at a time

After machine has done the work clean grain elevator fills up and transported to machine and into collecting bucket

Radiometric

Used in Europe and Germany

Radioactive isotope - total americium 241 read = total yield

Load cell

in agar tube less grain less tumble

Volume measurement

Finite space- one side is a light source other s a detector

full lots of light captured = calculate volume

Capacitance

Most common method of moisture sensing  

Not continuous has to be filled, Can't have things moving inside Fills, measures and cleans  

Autoswath for harvest

Maps every place where seeds has been planted

no seed no yield for that area

Header position switch

arrows built-in green green red

Operation delay

5-7 seconds until moisture and weight data is measured (distance from plant passed)

Yield monitoring for cotton

Spindles grabbing cotton and spin up into bowls  

Emitters count the number of cotton balls coming through  

Volumetric flow system

Yield monitoring for silage

Monitors total amount of material passing through cutter  

Cuts plant, sucks it into blades  

Mass of material = how much you open

deflection total = yield

Yield monitoring in grapes

Load cell system, cleaning the grapes ensuring the mud weight is not taken (needs to be calibrated)

Yield monitoring in citrus

different systems for use of mechanical harvesters - counting system uses optical sensor

Yield monitoring in alomonds

crop dries in the ground introduction to possible errors

Yield monitoring in broccoli

load cell monitoring installed on harvest aid - compares hand and machine weight

Yield monitoring hand harvested fruits

map trees in field using GPS using RFID tags on bins and trees

Present data

data aggregation, number of zones, color scheme

Yield scrubbing program

filtering data through scrubbers cleaning field data multiple filters can be used

Data aggregation

method to group data into yield ranges

equal count

equal interval

standard deviation

natural breaks

Interpretation

shows variation not what caused the variation

Spatial Resolution

aerial vs Satellite pixel size

Spectral Resolution

B&W vs color and Multispec vs Hyperspec

Radiometric Resolution

distinguishing between energy levels

Temporal Resolution

orbit cycle vs revise period with sun synchronous

Swath and revisit time

area of view and time of revisit determined by altitude

Fixed wing

larger payload and longer flight times but less maneuver

Rotor

highly maneuverable easy to operate but shorter flight times