Glossary of Terms

Glossary of Terms
Term	Meaning
AB Curves	Uses a manually driven curved path with two end points (beginning and end) to generate parallel passes.
Accuracy Bar Step Size	Used to set the value of offtrack distance each arrow on the Path Accuracy Indicator represents.
Activated	(4/4 Status of pie with “A”)—Resume switch has been selected and AutoTrac is steering the vehicle.
Adaptive Curves	Uses a manually driven initial pass, then guides off of previous pass.
Ag	The abbreviation for agriculture.
	The agricultural equipment division of John Deere.
AGC	Automatic Gain Control.
AMS	Ag Management Solutions.
Apex	Desktop software for field mapping. The successor to JD Office.
ASRC	Adjustable Seed Rate Controller. Legacy variable rate seeding controller for planters. One of the SeedStar generation 1 controllers. Also known as Variable Rate/Variable Drive, VRD, or VR. Companion to the Seed Monitor.
AT	AutoTrac.
ATU	Universal AutoTrac. A guidance system for vehicles that do not support AutoTrac directly.
AutoTrac	Assisted steering system based on satellite guidance that automatically steers the tractor through the field.
AutoTrac Deactivation Message	Shows operator why AutoTrac deactivated.
C&CE	The consumer and commercial equipment division of John Deere.
C&F	The construction and forestry division of John Deere.
CAN	Controller Area Network.
CCC	Customer Contact Center.
CCD	Chrysler Collision Detection. Later named SBI when it became a commercially available system.
CE	Conformité Européne (European mark signifying compliance of directives).
Circle Track	(Only available with optional PivotPro module.) Uses a center pivot center point location to define concentric circles (tracks).
Configured	(2/4 Status of pie)—Valid AutoTrac Activation, Tracking Mode has been determined and a valid Track 0 has been established. Correct StarFire signal level for AutoTrac Activation is selected. Vehicle conditions met.
DataCard	A card upon which setup and documented field data is stored. The datacard is PCMCIA on the GSD/MP and compact flash on the RCD.
DGPS	Differential GPS. A system of increasing the accuracy of GPS using a separately broadcast correction signal.
Display	General term which refers to both Original GreenStar Display and GreenStar 2 Display.
DOP	Dilution of Precision. A term used to quantify the accuracy of a GPS fix.
DRC	Dry Rate Controller.
DTAC	Dealer Technical Assistance Center.
DTC	Diagnostic Trouble Code.
ECU	Electronic Control Unit—A CPU-based device that monitors and/or controls a vehicle function. ECUs are typically networked together using the CAN.
EGNOS	European Geostationary Navigation Overlay Service. The European DGPS signal.
Enabled	(3/4 Status of pie)—Steer Icon has been selected and “Steer On” is displayed.
FD	Field Doc.
FD-MBA	Field Doc Map-Based Application.
Field Doc	A suite of applications on the MP and RCD that record the inputs on a field. The Field Doc applications are capable of recording map-based variable rate inputs.
FlexBox	One of a family of next generation controller systems used throughout the Ag division.
GAI	GPS Accuracy Indicator.
GPS	Global Positioning System.
GSD	GreenStar Display.
GSD2100	One of the RCD GreenStar displays. A 8.4" VGA color screen in a metallic silver housing.
GSD2600	One of the RCD GreenStar displays. A 10.4" VGA color touchscreen in a metallic silver housing.
Guidance Off	For use when only documentation is needed.
GVC	Global Vehicle Communications.
Harvest Doc	A suite of applications on the MP and RCD that record the crop yield on a field. The Harvest Doc applications are capable of recording map-based crop yields.
HDOP	Horizontal Dilution Of Precision.
Installed	(1/4 of Status pie)—AutoTrac SSU and all other hardware necessary for use are installed.
ISO	International Standards Organization.
KeyCard	PCMCIA card that holds and activates all AMS software on the Mobile Processor.
L-Band	Frequency band containing the StarFire correction signals transmitted from the Inmarsat satellites.
L1	One of the frequencies used by the GPS satellites.
L2	One of the frequencies used by the GPS satellites.
L5	A new frequency available in Block III GPS satellites for additional accuracy.
LCD	Liquid Crystal Display - a low power, flat panel display.
Lead Compensation	Shows how far down current track guidance looks to for such things as turns. Used with Parallel Tracking only.
LED	Light Emitting Diode.
MP	Mobile Processor.
NA	North America.
NMEA	National Marine Electronics Association.
NMEA-0183	The standard for GPS data transmission between the receiver and any downstream processor.
PDOP	Position Dilution of Precision.
Performance Monitor	Means of displaying status information gathered from the cab of John Deere equipment. This includes fuel consumption and equipment performance.
PF	Precision Farming.
PLD	Programmable Logic Device.
RCD	Reconfigurable Display (successor to the GreenStar Display).
RS232	A serial communication interface specification with bandwidth up to 115k bits per second at up to 50 feet.
RTK	Real Time Kinematic. A local, ground based differential correction technique involving a fixed receiver calculating position offset vectors.
Row Finder	Used in standing row crop applications to mark end of a pass and guide operator to next pass.
SF	StarFire.
SF1	StarFire differential GPS with standard accuracy, ~14 inches pass-to-pass at 2σ.
SF2	StarFire differential GPS with enhanced accuracy, ~4 inches pass-to-pass at 2σ.
Set Track 0	Allows the operator to set initial track which all subsequent tracks are created from.
SM	Seed Monitor. Legacy seeding monitor controller. One of the SeedStar Generation 1 controllers. Companion to the ASRC.
SNR	Signal-to-Noise Ratio.
SPFH	Self Propelled Forage Harvester—A machine to harvest crops such as hay or corn for use as animal forage.
SSU	Steering System Unit. The controller on the vehicle that transforms errors in position or heading to commands for the steering actors.
StarFire	The AMS GPS receiver system. This consists of a multichannel receiver that operates on the L1 and L2 bands, an antenna, a sealed housing, and a terrain compensation unit (on later versions). All versions of the StarFire receiver can receive the GPS L1 & L2 signals, the WAAS differential correction signal, and the SF1 and SF2 correction signals. All versions produce a 5Hz CAN bus output and a NMEA 0182 standard output on the RS-232 interface.
	The Navcom differential satellite correction signal. Navcom tracks the GPS satellites using a global network of base stations. The data from these stations is processed and correction terms are generated to compensate for satellite position and clock errors. There are two classes of StarFire correction service: SF1 provides a two-sigma pass-to-pass accuracy of fourteen inches, and SF2 provides four-inch accuracy.
Shift Track	Used to adjust position of machine left, center or right of set track. Shift track can be used to compensate for GPS drift. Drift is inherent to any satellitebased, differentially corrected GPS system.
Straight Track	Uses straight line parallel passes.
TCM	Terrain Compensation Module (formerly known as the IMU)—Corrects GPS data for Roll angle and yaw angle errors.
TECU	Tractor ECU. This is defined in ISO 11783 Part 9.
Tracking Tones	Can be set to alert operator at a specified offtrack distance.
Turn Predictor	Alerts operator by predicting the end of pass. This feature can be turned on or off by selecting or deselecting Turn Predictor check box.
Turning View	Can assist operators to guide vehicle from one pass to the next by showing an overhead view of the field.
USB	Universal Serial Bus.
VDOP	Vertical Dilution Of Precision.
VR	Variable Rate Controller. Another term for the ASRC. One of the SeedStar Generation 1 controllers.
VRF	Variable Rate Fertilizer Controller. Planter controller used to control the variable application of liquid fertilizer.
VT	Virtual Terminal.
WAAS	Wide Area Augmentation Service.
Wedge Box	One of a family of general and special purpose controllers used throughout the Ag division.
WW	Worldwide.