Environmental factors

Research questions Environmental factors

Egon:
1. Will LBS have positive impact on the environment, due to less searching time and better location based information. (less use of energy / fuel??)

Reza:
1. How far is the air in major business areas over crowded with the same frequency?

Amarantha:
1. Do satellites affect/change the earth's atmosphere in any way?
2. How are satellites disposed of at the end of their useful life? How long is that life?
3. What effect will environmental changes have on the GPS infrastructure?

Werner:
1. To what extend can the phenomenon of electrical pollution limit the expansion of the use and application of LBS ? ([1])

Research Answers Environmental Factors

GPS satellites and the environment
GPS satellites in themselves do not directly affect the environment in a negative or positive manner. However, they do deplete the earth's natural resources on launch. They use up massive amounts of fuel at that time. Once in space, they are however powered by solar energy for sending the signals. They must still have fuel on board for movement for their remaining useful life. A GPS Satellite has a lifetime of 5 - 10 years. There are currently 60 working GPS satellites in orbit. Replacements are continously being built and sent into orbit.

Disposal of GPS satellites
Satellites can be disposed of in two ways. They can move up to a disposal orbit(~300 km further) or they can fall from space to Earth.

Falling from orbit
When a satellite falls from orbit, 10 to 40 percent of its mass survives reentry and falls at random locations on Earth. To date noone has been killed or injured by this. The debris is also not cleaned up.

Moving to a disposal orbit
Studies show that satellites placed in disposal orbits can in 20-40 years encroach into the operating constellation. These can then collide with operating satellites or can explode and shower the operating satellites with debris.
With multiple satellite constellations such as the Galileo, GPS and Glonass, collisions become a bigger problem as the heights of the normal orbits and therefore disposal orbits vary. The russian Glonass, which has about 100 failed satellites in disposal orbits could pose a collision problem 40 years from now. There is currently no known solution for collision issues.
Some countries also simply abandon their failed satellites without moving them out of the operating ring.
Space pollution is becoming an increasing problem.

Effect of the environment on satellites
Research has shown that rising levels of carbon dioxide in the Earth's atmosphere is actually decreasing the density of the thermosphere(where GPS satellites are located). This will allow space debris to orbit more quickly, and impact satellites more frequently.

Positive effects of GPS on environment
GPS technologies can also have a positive effect on the environment:
1. GPS technologies are dramatically improving transportation on land, at sea and in the air. It can reduce fuel consumption by helping establish more efficient routes and schedules.
2. GPS can be also used to support the investigation of hazardous waste sites, the mapping of ecosystems, the monitoring of oil spills and clean-up efforts, and the tracking and mapping of airborne pollutants.

Adverse effects of GPS on earth's environment
GPS technology in itself does not adversely affect the earth's environment. However the numerous devices built around this and other technologies is what causes issues such as electrical and electromagnetic pollution. So we cannot say that this is a direct effect of GPS technology. However, there is a health effect (FR radiation) of mobile phone and wireless devices. There is not conclusive evidence as yet and research is being done. However, the recommendations are to proceed with caution.

References

1. Where satellites go when they die
2. Disposal procedures
3. Effect on environment
4. Space pollution
5. Global warming and satellites
6. Health report