Firmware STEADYLINE®

SMOOTH TRANSITIONS BETWEEN

POSITIONING MODES FOR

STEERING APPLICATIONS

REDUCED POSITION JUMPS

NovAtel’s STEADYLINE technology reduces position jumps that can occur when a

GNSS receiver changes positioning modes. This eect is especially evident when a

receiver transitions from a high accuracy RTK position solution to a lower accuracy

solution such as PPP (TerraStar), DGPS, SBAS+GLIDE or even autonomous GLIDE™.

Smooth transitions are extremely important for precision agricultural steering

applications where sudden jumps are disruptive.

FIGURE 1: POSITIONING CHANGE WITHOUT STEADYLINE

STEADYLINE internally monitors the position osets between all the positioning

modes in the receiver. When the current positioning mode becomes unavailable,

the receiver automatically transitions to the next most accurate positioning mode.

To handle the transition, STEADYLINE supports multiple accuracy modes including

Maintain, Transition and Prefer Accuracy.

There are four STEADYLINE modes: Maintain, Transition, Prefer Accuracy and UAL.

MAINTAIN

When the receiver transitions to a dierent positioning mode, it maintains the position

oset calculated to limit a potential real position jump. The receiver continues to apply

the position oset to all positions calculated in the new positioning mode (Figure 2).

FIGURE 2: STEADYLINE MAINTAIN

TRANSITION

When the receiver transitions to a dierent positioning mode, the position oset is

applied to the calculated position to limit a potential real position jump. The position

then slowly transitions to the new reference position type over a user speciﬁed period

of time (Figure 3).

FIGURE 3: STEADYLINE TRANSITION

Position

Intended Path

change to

lower accuracy

solution

change to

higher accuracy

solution

Position

Intended Path

change to

lower accuracy

solution

change to

higher accuracy

solution

Position

Intended Path

change to

lower accuracy

solution

change to

higher accuracy

solution

Provides smooth transitions

between positioning modes for use

in steering applications

FEATURES

Reduces position jumps when

switching between RTK, PPP

(TerraStar), DGPS, WAAS and

GLIDE positioning modes

Available on OEM6® receivers

If you require more information about

Firmware, visit www.gnss.ca

BENEFITS

STEADYLINE

PREFER ACCURACY

In Prefer Accuracy mode, the positioning mode change depends on the accuracy level

of the positioning modes. When the position mode changes from a more accurate to

a less accurate mode the receiver uses the Maintain option. When the position mode

changes from a less accurate to a more accurate mode the receiver uses the Transition

option.

FIGURE 4: STEADYLINE PREFER ACCURACY

USER ACCURACY LEVELS (UAL)

User accuracy levels can be set to change the solution type in the GPGGA and

BESTPOS messages. When User Accuracy Level mode is used along with STEADYLINE,

the accuracy mode is adjusted based on the current estimated accuracy.

In Figure 5 below, the user has set operational and warning limits using the

UALCONTROL command. At point A, higher accuracy corrections are lost and the

receiver changes to a lower accuracy solution. When the position reported by the

receiver is within the operational limits, the solution type reported in the BESTPOS

message is OPERATIONAL and the receiver uses the Maintain accuracy mode. When

the position reported is between the operational and warning limits (B), the receiver

uses the Prefer Accuracy mode and reports the position type as WARNING in the

BESTPOS message. When the position reported by the receiver returns to below the

Operational limit (C), the solution type reported is OPERATIONAL but the receiver

continues to use the Prefer Accuracy mode until the position oset is removed. Aer

the oset is removed (D), the receiver transitions to the Maintain accuracy mode.

FIGURE 5: STEADYLINE UAL-WARNING LIMIT EXAMPLE

Operational

Limit

Warning

Limit

Operational

Limit

Warning

Limit

A B C D

If the receiver position exceeds the Warning limit (point C in Figure 6 below), the solution

type reported is OUT_OF_BOUNDS and the STEADYLINE feature is automatically disabled.

FIGURE 6: STEADYLINE UAL-OUT OF BOUNDS EXAMPLE

Operational

Limit

Warning

Limit

Operational

Limit

Warning

Limit

A B C

Position

Intended Path

change to

lower accuracy

solution

change to

higher accuracy

solution

For the most recent details of this product,

visit www.gnss.ca

gnss.ca

sales@gnss.ca

1-855-OEM-GNSS (U.S. and Canada)

or 778-430-5999

China 0086-21-68882300

Europe 1-855-636-4677

SE Asia and Australia 1-855-636-46771

Version 3 Speciﬁcations subject to change without notice.

STEADYLINE and GLIDE are trademarks of NovAtel Inc.

NovAtel is a registered trademark of NovAtel Inc.

D20452 July 2016 Printed in Canada.