The Best GNSS Receiver
Posted: Sat Oct 22, 2016 1:48 pm
Is the SIMRAD HS60 the best GNSS receiver for your boat? Perhaps--not because it is the best GNSS receiver you can get, but because it is also a compass or heading sensor. The HS60 is an interesting combination of technologies. In one housing it has:
--a NMEA-2000 interface to connect to other navigation electronics
--two GNSS antennas and a GNSSreceiver to determine both position and heading
--a tilt sensor, and
--a gyro compass.
The NMEA-2000 interface is as you'd expect on a modern device. In addition to providing a path for the data, it also powers the unit, which only consumes 2-Watts of electrical energy. This greatly simplifies installation.
The GNSS receiver is able to receive the Air Force GPS constellation L1 coarse acquisition signal, the normal civilian signal, and augment with correction data from various spaced-based augmentation systems (SBAS) like WAAS (in North America) and EGNOS (in Europe). The receiver is a modern implementation which retains SBAS correction data for as long as 40-minutes. This allows the receiver to continue to deliver an enhanced precision position solution even if the SBAS satellite is out of view for short durations. SIMRAD rates the receiver when SBAS is available for 1-meter-RMS accuracy 95-percent of the time. Without SBAS the receiver is rated at 3-meters-RMS 95-percent of the time.
Most significant is the inclusion of two antennas in the housing. This permits the GNSS receiver to calculate a compass heading solution with an accuracy of 2-degrees. Since this method does not use a magnetic sensor, it is free from interference from the usual magnetic influences found on boats from ferrous metals or strong electrical currents.
The HS60 also has tilt sensors that deliver data on heave, roll, and pitch. The inclusion of heave data is going to be attractive to SONAR enthusiasts. Some of the higher-end Simrad SONAR devices can accept heave data. What is heave? It is the up-down vertical motion of your boat, usually due to waves or swell. By having heave data available, a sophisticated SONAR can correct its depth measurements to reduce the influence of waves on the boat. You've all seen what a SONAR display looks like when you are sounding in waves--the bottom contour looks like a sine-wave curve as the depth to the bottom changes as your boat rides up and down in the waves. Heave compensation can eliminate that. Of course, you need a sophisticated sounder to be able to do that.
The gyro compass also augments the GPS compass by providing faster updates of heading changes and also taking over (for as long as three minutes) if the GPS compass cannot get a heading solution. Note that this is a gyroscope compass, not a magnetic compass. Again, no problems with magnetic interferences from the boat.
All of this comes with a price. The HS60 is not in the same market as a POINT-1. This device has an MSRP of $1,000. If that seems a bit expensive, compare the HS60 to its bigger cousin, the HS70 which sells for $2,250. See more on the HS60 at
http://store.navico.com/Products/000-12308-001
--a NMEA-2000 interface to connect to other navigation electronics
--two GNSS antennas and a GNSSreceiver to determine both position and heading
--a tilt sensor, and
--a gyro compass.
The NMEA-2000 interface is as you'd expect on a modern device. In addition to providing a path for the data, it also powers the unit, which only consumes 2-Watts of electrical energy. This greatly simplifies installation.
The GNSS receiver is able to receive the Air Force GPS constellation L1 coarse acquisition signal, the normal civilian signal, and augment with correction data from various spaced-based augmentation systems (SBAS) like WAAS (in North America) and EGNOS (in Europe). The receiver is a modern implementation which retains SBAS correction data for as long as 40-minutes. This allows the receiver to continue to deliver an enhanced precision position solution even if the SBAS satellite is out of view for short durations. SIMRAD rates the receiver when SBAS is available for 1-meter-RMS accuracy 95-percent of the time. Without SBAS the receiver is rated at 3-meters-RMS 95-percent of the time.
Most significant is the inclusion of two antennas in the housing. This permits the GNSS receiver to calculate a compass heading solution with an accuracy of 2-degrees. Since this method does not use a magnetic sensor, it is free from interference from the usual magnetic influences found on boats from ferrous metals or strong electrical currents.
The HS60 also has tilt sensors that deliver data on heave, roll, and pitch. The inclusion of heave data is going to be attractive to SONAR enthusiasts. Some of the higher-end Simrad SONAR devices can accept heave data. What is heave? It is the up-down vertical motion of your boat, usually due to waves or swell. By having heave data available, a sophisticated SONAR can correct its depth measurements to reduce the influence of waves on the boat. You've all seen what a SONAR display looks like when you are sounding in waves--the bottom contour looks like a sine-wave curve as the depth to the bottom changes as your boat rides up and down in the waves. Heave compensation can eliminate that. Of course, you need a sophisticated sounder to be able to do that.
The gyro compass also augments the GPS compass by providing faster updates of heading changes and also taking over (for as long as three minutes) if the GPS compass cannot get a heading solution. Note that this is a gyroscope compass, not a magnetic compass. Again, no problems with magnetic interferences from the boat.
All of this comes with a price. The HS60 is not in the same market as a POINT-1. This device has an MSRP of $1,000. If that seems a bit expensive, compare the HS60 to its bigger cousin, the HS70 which sells for $2,250. See more on the HS60 at
http://store.navico.com/Products/000-12308-001