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Geography 222 Midterm > GPS > Flashcards

Flashcards in GPS Deck (22)
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1
Q

How many satellites orbiting earth?

A

24

2
Q

What type of signal does it send?

A

Time signal

3
Q

What are some similar systems launched by Russia and Europe?

A

GLONASS (Russia) and Galileo (Europe)

4
Q

What does GPS technology provide?

A

Accurate location information

5
Q

What does GPS rely on?

A

It relies on a space-based network of satellites

6
Q

How is accuracy maintained?

A

By the control system

7
Q

GPS systems (3)

A
  1. Space System
  2. Control system
  3. User system
8
Q

Space system:

A

24 satellites, 6 orbital tracks so at least 4 satellites per track. Provides a minimum of 5 to 8 satellites anywhere on earth.

9
Q

Orbit time of a satellite?

A

11 hours and 58 min

10
Q

What do GPS receivers convert satellite signals into?

A

It converts it into position, velocity, and time estimates. XYZ (position, location and velocity) and time.

11
Q

Control systems: What is the main purpose of control systems?

A

Is to maintain and update satellites

12
Q

What is selective availability?

A

is a system the government can use to degrade public accuracy.

13
Q

What are the 2 signals produced by the control systems?

A

SPS: Standard positioning service
and
PPS: Precise positioning service.

14
Q

User System:

A

Consists of GPS signal receivers.

15
Q

How can you improve accuracy?

A

Removal of selective availability and the use of different GPS receivers.

16
Q

What signal can consumer receivers not receive.

A

Consumer receivers cannot detect PPS.

17
Q

What is the equation the satellites use?

A

Trilateration

18
Q

What are some sources of errors of GPS?

A
  1. Atmosphere/ionosphere
  2. Atomic clock deviation on SV’s (small)
  3. Non-direct signal path between SV and receiver
  4. Receiver math
  5. Geometry
  6. Blocked line of sight (buildings)
19
Q

Geo-reference:

A

The act of coordinating collective data to a common global reference, other related topics included Geo-coding and address matching.

20
Q

Geographic Information Science:

A

The science related to examining and studying the technology associated with collecting, storing and processing spatial data. Research expands the technology.

21
Q

Geographic Information Studies:

A

Studies related to the societial cobntect of geographic information systems.

22
Q

Geographic information system?

A

The integrated hardware and software to collect, store and process spatial data.