Using a Dual Frequency/Multi-Band Outdoor Handheld

The following outdoor handheld devices feature "Multi-Band" or Dual-frequency GNSS (Global Navigation Satellite System) capability, which can help to improve location accuracy:

• eTrex® Solar

• Foretrex® 801 | Foretrex® 901 Ballistic Edition

• GPSMAP® 65 | GPSMAP® 65s

• GPSMAP® 66sr

• GPSMAP® 67 | GPSMAP® 67i

What Advantages Do Dual-Frequency Handhelds Have Over Older Models?

• Dual-frequency systems allow for more consistent tracklogs and improved positioning when using the device in challenging environments (e.g. around tall buildings in urban canyons as well as tree cover)

• The location accuracy of older models is within about +/- 3 meters or 10 feet under ideal conditions, but dual-frequency systems are accurate within about +/- 2 meters or 6 feet under ideal conditions

• Detect (and reject) reflected satellite signals better than a single frequency receiver

• Better equipped to account for and correct errors that can be introduced by atmospheric effects (e.g. ionosphere errors)

How Do I Use Dual-Frequency?

GPSMAP Series

1. Press MENU twice to access the main menu.

2. Select Setup.

3. Select System.

4. Select Satellite.

   • Select Satellite System > Multi-GNSS to enable the device to track satellites from multiple satellite constellations.^{1, 2}

   • Select Multi-Band > On to enable dual-frequency so the device can track more than one signal from each satellite when using Multi-GNSS.

     • NOTE: The GPSMAP 66sr displays x2 above the GPS signal strength bars when Multi-Band is enabled.

       The WAAS/EGNOS setting is not available on Dual-frequency devices as Dual-frequency eliminates the need for WAAS/EGNOS.

eTrex Solar

1. From the main menu, select Settings.

2. Select System.

3. Select Satellite.

   • Select Satellite System > Multi-GNSS to enable the device to track satellites from multiple satellite constellations.

   • Toggle on Multi-Band to enable dual-frequency so the device can track more than one signal from each satellite when using Multi-GNSS.

     • NOTE: The WAAS/EGNOS setting is not available on Dual-frequency devices as Dual-frequency eliminates the need for WAAS/EGNOS.

Foretrex 801 and 901 Ballistic Edition

1. Press PAGE until you reach the menu page.

2. Select SETUP.

3. Select SYSTEM.

   • Select GPS MODE > MULTI-GNSS to enable the device to track satellites from multiple satellite constellations.^{1, 2}

   • Select MULTI-BAND > ON to enable dual-frequency so the device can track more than one signal from each satellite when using Multi-GNSS.

     • NOTE: The WAAS/EGNOS setting is not available on Dual-frequency devices as Dual-frequency eliminates the need for WAAS/EGNOS.

How Does Dual-Frequency Work?

Dual-frequency systems use multiple frequency bands and allow for more consistent tracklogs and improved positioning when using the device in challenging environments. This means that the receiver tracks more than one radio signal from each satellite on different frequencies, which can help to reduce errors caused by environmental interference.

The illustrations below show how dual-frequency systems are better able to filter out inaccurate signals that are reflecting off of buildings, trees, or mountains.

The following table shows what frequency bands can be tracked depending on the satellite settings that have been enabled and device location:

Some satellite systems are not going to be available in some areas. For example, the IRNSS system isn't available on the west coast in Salem, OR. Customers will need to check the satellite provider's website for coverage information.

¹ Multi-GNSS satellite systems include GPS, GLONASS, GALILEO, QZSS, BeiDou, and IRNSS (NavIC). Some satellite systems are not available in all areas of the globe. For more details, see - https://www.gps.gov/systems/gnss/

² GLONASS is not available on inReach compatible devices. BeiDou is not available on the GPSMAP 65 series or GPSMAP 66sr.