YIELD DATA FORMATS:APPLES AND WATERMELONS

Scott Drummond and Ken SudduthUSDA-ARS Cropping Systems and Water Quality Research UnitColumbia, MO

Once upon a time, there were two ASCII yield data formats: AgLeader Advanced Text John Deere Greenstar Text

They were essentially the same…

And life was good…

Yield Data Formats

Then came :

binary formats

proprietary formats

shapefiles

And that’s where the trouble started…

Yield Data Formats

Yield = Grain / Area

Where:

Grain = Grain volume for a time intervalArea = Harvest area for that time interval

Back to Basics

Where:k = a constant to deal with unit conversion factorsMC = correction factor, based upon moisture

sensor.Flow, Width and Velocity are all “sensed” inputs.

More accurately

VelocityWidthFlowMCYield

•

••= k

where i = time for grain to reach moisture sensor j = time for grain to reach grain flow sensor

Complex form with latency

)Velocity()Width()Flow()MC()Yield(

ttjt itkt

•

• ++= •

AgLeader Advanced Text Format:

1) Longitude decimal degress, negative in W hemisphere2) Latitude decimal degrees, negative in S hemisphere3) Grain Flow pounds per second (Not pounds per interval!)4) Time seconds5) Logged Interval seconds 6) Interval Distance inches travelled over interval (Not in/s!)7) Swath Width inches 8) Grain_Moisture percent wet basis9) Header_Status unitless, 1 = harvesting, 0 = not harvesting10) Pass_Number unitless, generally +1 each header up/down cycle11) Additional_Info unitless

“I need to use Yield Editor. Here’s my data…”

Most common HELP ME request

“I need to use Yield Editor. Here’s my data…”

Next most common HELP ME request

Why do they call it a shapefile when it’s really 3+ files? Are the shapes points? Polygons? A combination? Attribute table (.DBF) usually has NO (X,Y) data in the file. The attribute table OFTEN has no unit designations in heading. The attribute table may have everything we need – or nothing at all. How do I get my clean data back into the shapefile? Working with Shapefiles is… WORK.

Shapefiles and issues…

DBF file contains all attributes for objects…

This dataset is the DBF of a shapefile export from SMS

Looks somewhat promising, having Distance, Swath, Duration, etc…

BUT – No (X,Y) position information for each object.

Use ArcGIS/ArcMAP to get XY data

XY data appended to attribute table.

Convert units, identify critical columns.

Reorder critical columns and save to CSV

Read the .CSV file into Yield Editor

Clean the data in Yield Editor

Export EVERYTHING from Yield Editor

Append desired fields onto .DBF file, save in Excel

Convert .xlsx file back over original .dbf file

Confirm shapefile opens with new attributes

Can we use shapefiles for yield data? Sometimes… Always a bit of a risk dealing with these complex datasets Overhead and potential for problems IS CONSIDERABLE Probably best to clean data before converting to shapefile Standardization of formats is desirable

Conclusions