Polar G3 GPS Receiver W.I.N.D

Polar G3 GPS Receiver W.I.N.D

Suited for: RS800, RS800CX, RS800CX Bike, RS800CX Multi, RS800CX Run, RS800G3, RS800SD.
Contents:
G3 GPS sensor with arm band
Carrying case for sensor
G3 GPS sensor instruction booklet
Training plans
Alkaline 1.5V LR6 battery
Two year warranty

This g3 sensor makes the RS800 the most comprehensive planning and analysis tool for athletes who train across multiple disciplines. Incorporating the SIRF-III GPS chipset, the sensor provides excellent coverage, fast time to first fix and optimal power consumption. A single AA battery provides up to 20 hours continual use. Weighing only 80grams (inc. battery) and water resistant to 3 bar, g3 is extremely compact and built to withstand the harshest conditions of even the most extreme adventure sports.
GPS Unit:
Gives speed and distance flexibility in all outdoor sports
Very robust and water resistant
Ultralight, composite materials for optimal wear
2.4 Gigaherz

Battery Power:
Uses user changeable AA battery for power which enables long trips without battery charging, can use rechargeable, recommended especially for low temperature use (below 0 degrees C)

Low battery notice is given when exercise starts, not during exercise (RS800 feature)

Typical battery lifetime in warm conditions 10 hours, and 15 hours in low power mode

Lithium batteries (expensive) can extend the battery change interval to even 40h

Some battery models (Energizer) keep high voltage long and loose power rapidly in the end. Low battery notice displayed only short time before shutdown

Some batteries gain some voltage back after shutdown (Energizer) after restart they might show good battery condition but after 3-5 minutes shut down again

GPS Sensor technology:
GPS (Navstar) is a system that enables calculation of accurate position anywhere on earth based on special GPS satellite signals>

Built and anaged by U.S. Dept. of Defence, free global use

A GPS receiver calculates its position by measuring the distance between itself and three or more GPS satellites.

GPS is widely used in aerospace, military, vehicle and personal navigation, map making, land surveying and science.


GPS Sensor - Speed and Distance Measurement Solution:
Uses SiRF Star III low power receiving chipset as the GPS solution is very sensitive and accurate and supplies GPS data to microcontroller once per second (every 2 seconds if in low power mode).

Polar embedded software in microcontroller calculates speed form position changes if speed changes very rapidly, filtered SiRF speed is used until steady speed is detected. It is optimized for accurate and stable speed and distance display in human-powered sports.

Normally speed display gets steady after 6-10 seconds after step change in speed

Speed information is sent to RS800 via Polar WIND protocol

GPS technology limitations:
GPS positioning requires satellite visibility to work, thus it will reliably work only outdoors

Buildings, hills and vegetation can potentially prevent satellite visibility

GPS signal is RF (radio frequency) signal, will not go through metal, water, other materials can degrade signal quality

Rain, fog, snow (water), human body sweat can create bad conditions for GPS signal

Altitude measurement accuracy is 2-3 worse than position accuracy. GPS not usable for sports altitude measurement