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AFS Accuracy 

Choose the level of accuracy that best fits your operation.  

 

Fitting a GPS antenna to your machinery opens up Advanced Farming Systems capability to include guidance, automatic steering, sprayer boom control, yield mapping and much more. While satellite navigation in a car typically has a positioning accuracy of about 16.5 ft. (5m), Case IH AFS® equipment can achieve sub-inch (2.5 cm) accuracy, repeatable 95 percent of the time.

 

Know Your Accuracy Options

 

DIFFERENTIAL GPS (DGPS) WITH WAAS OR
OMNISTAR CORRECTION

A vehicle with a GPS antenna receives GPS signals from the
GPS satellite constellation. The Wide Area Augmentation System (WAAS) and OmniSTAR® services have many GPS receivers at known reference locations that send the correction messages to control stations, which then uplink the message to a geostationary satellite (WAAS or OmniSTAR). The geostationary satellite then sends the correction message to the GPS antenna on the vehicle, which applies the correction.

     

    WAAS

    6 - 8-in. (15 - 20-cm) pass-to-pass accuracy
    Sub-meter repeatable accuracy
    < 1 min convergence
    The Wide Area Augmentation System (WAAS) was developed by the Federal Aviation Administration to augment the Global Positioning System (GPS), with the goal of improving its accuracy, integrity and availability. It is available to all at no charge.

     

    OmniSTAR VBS
    6 - 8-in. (15 - 20-cm) pass-to-pass accuracy
    20-in. (50-cm) repeatable accuracy
    < 1 min convergence
    OmniSTAR VBS is best suited for:
    • Operators who desire a quick start-up time, and don’t need the highest level of accuracy or repeatability
    • Broadacre crop spraying, tillage applications and other applications in
    which accuracy and repeatability isn’t of the highest concern

     

    OmniSTAR G2
    3 - 5-in. (8 -13-cm) pass-to-pass accuracy
    6 - in. (15-cm) repeatable accuracy
    < 40 min convergence
    OmniSTAR G2 is best suited for:
    • Use when more reliable coverage time is necessary, due to the use of GLONASS satellites in addition to the standard GPS satellites
    • High-performance broadacre spraying, planting and land-tillage applications
    • Operations in areas with open views of the sky at all times


     

    OmniSTAR XP
    3 - 5-in. (8 -13-cm) pass-to-pass accuracy
    6 - in. (15-cm) repeatable accuracy
    < 40 min convergence
    OmniSTAR XP is best suited for:
    • High-performance broadacre spraying, planting and land-tillage applications
    • Operations in areas with open views of the sky at all times

    OmniSTAR XP is a worldwide, dual-frequency, high-accuracy solution. It is an L1/L2 solution requiring a dual-frequency receiver. While it is slightly less accurate than OmniSTAR HP, it is available worldwide.

     

     

    OmniSTAR HP
    2 - 4-in. (5 -10-cm) pass-to-pass accuracy
    4-in. (10-cm) repeatable accuracy
    < 40 min convergence
    OmniSTAR® HP is best suited for:
    • High-performance broadacre seeding, planting spraying and harvesting applications
    • Operations in areas with open views of the sky at all times

    OmniSTAR HP is a more accurate solution. Like the XP service, it is an L1/L2 solution requiring a dual-frequency receiver. Data from OmniSTAR’s network of reference sites is utilized together with atmospheric corrections.
    It operates in real time and without the need for local base stations or telemetry links.

     

    CenterPoint RTX
    < 1.5-in. (3.8-cm) pass-to-pass accuracy
    < 1.5-in. (3.8-cm) repeatable accuracy
    < 30 min convergence
    CenterPoint RTX is best suited for:
    • Farms located anywhere in the world
    • Farms outside of RTK base station coverage areas
    • Is compatible with AFS 372 receiver as well as FM-1000 and FM-750
    • Use with the FM-1000 and FM-750 displays
    • Use with row crops and other applications requiring 1.5” (3.8 cm) accuracy

     

    CenterPoint VRS
    < 1-in. (2.4-cm) pass-to-pass accuracy
    < 1-in. (2.4-cm) repeatable accuracy
    < 1 min convergence
    CenterPoint VRS™ is best suited for:
    • Farms in areas with robust cellular coverage
    • Operations spread out over a large geographic area
    • Use with row crops, strip tilling, and other applications requiring sub‑inch (sub 2.5 cm) accuracy

    CenterPoint VRS is a correction signal delivered to a vehicle via a cellular modem. The correction data comes from a central server, which is continually monitoring and analyzing data. The system can ensure near-RTK accuracy because of the way in which the signal is processed through the VRS server.


    CenterPoint RTK
    < 1-in. (2.4-cm) pass-to-pass accuracy
    < 1-in. (2.4-cm) repeatable accuracy
    < 1 min convergence
    CenterPoint RTK is best suited for:
    • Farms within 8 miles of an established RTK base station or
    base station network
    • Farms without line-of-sight obstructions such as hilly terrain or an abundance of trees
    • Use with row crops, strip tilling, land leveling and drainage applications in which the best horizontal and vertical accuracy is required


    RTK is a highly precise technique that results in one-inch, year-to-year accuracy. It requires two specialized GPS receivers and two radios. One GPS receiver is set up as a base station within an 8 mile (12 kilometer) radius of the field you are working so it can send the correction message to the roving receiver. Both receivers collect extra data from the GPS satellites, known as an L2 Band that enables better precision. There is an unlimited number of users, so it is ideal for large farms and fleet users.

     

     

     

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