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1

What is GPS

Global positioning systems

2

What is geomatics

Geographical analysis using computers, tying data with a particular place

3

What is the base before we split it into sections

Reality

4

What data can we add to gis maps!

Data labels and values

5

What is remote sensing?

Observing a particular feature from a distance

6

What is an example of remote sensing

Satellite data

7

Why is remote sensing seeing a rise in popularity

Drones and technology is becoming cheaper so starting to get rolled out on a larger scale

8

Who can generate their own remote sensing data

Anyone

9

What is the principle to gis

Network of orbiting stallites

10

What is the issue with old aciol maps

All the information is in one place/document hard to distinguish the data

11

What is the desire of change from gis

The desire to have more than one theme

12

Who discovered the cause of a cholera outbreak in London using rudimentary GIS

Jon Snow

13

What are the main GPS systems in use today?

NAVSTAR USA and Glonass Russia, also Galileo Europe

14

How many satellites are run by nav star

24, each with 12 hour orbit

15

How does a GPS find your location

Triagulates data from 3 points

16

How manny satellites are needed to calculate altitude

4

17

Is every GPS position 100% accurate

No

18

What is the standard error range for GPS location

- + 25m 95% of the time

19

What measures the accuracy of a GPS fix

Dilution of precision

20

What will some GPS systems do while you are collecting data

Give a constant DOP reading

21

What causes delays through the atmosphere

Ionisation as it passes through the atmospheres, some have a built in counter delay but this may not be accurate

22

What is signal multi path?

Multiple signals from the state lites which is bouncing of buildings,
No way of accounting for this apart from making sure you can see as many satellites as possible and move into an open space

23

What is a receiver clock error?

Clocks on phones may be out compared with the atomic clock, meaning any time differences would screw up data

24

What are orbital errors

Satellite orbit can get out of sync so data might be screwed

25

Why might people manually turn down or distort satellite signal,

Selective availability, US used it to stop enemies using their satellites or finding out about military bases ect, terminated in 2000 which improved civilian reception

26

How can we improve gps accuracy?

Use systems such as differential GPS, uses 2 receivers rather than just one

27

How does differential GPS work

Error and position should be accurate for both receivers, if they are not you subtract the error for our fixed base station from GPS receiver

28

What is vector data

The simplest forms of data, points lines polygons and surfaces

29

What is topology

How different data fit together and overlap

30

What does GIS use

Spatial data