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Flashcards in chapter 3 sensors and platforms part 2 Deck (83)
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1

There are several broad categories of basic sensor system types such as

passive vs. active, and imaging vs. nonimaging

2

Passive vs. active refers to

the illumination source of the system

3

imaging vs. nonimaging refers to

the form of the data

4

A variety of different sensors fit in these categories, which are

not mutually exclusive.

5

Passive sensors measure

light reflected or emitted naturally from surfaces and objects

6

Passive sensors measure light reflected or emitted naturally from surfaces and objects. Such instruments

merely observe

7

Passive sensors measure light reflected or emitted naturally from surfaces and objects. Such instruments merely observe, and depend primarily on

solar energy

8

Passive sensors measure light reflected or emitted naturally from surfaces and objects. Such instruments merely observe, and depend primarily on solar energy as the

ultimate radiation source

9

Passive sensors measure light reflected or emitted naturally from surfaces and objects. Such instruments merely observe, and depend primarily on solar energy as the ultimate radiation source illuminating

surfaces and object

10

Active sensors (such as ...............)

radar and lidar systems

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Active sensors (such as radar and lidar systems) first

emit energy (supplied by their own energy source) and then measure the return of that energy after it has interacted with a surface.

12

Use of data collected by passive sensors often requires

accurate measurements of solar radiation reaching the surface at the time the observations were made

13

Active sensors :
Use of data collected by passive sensors often requires accurate measurements of solar radiation reaching the surface at the time the observations were made. This information allows for the

correction of "atmospheric effects"

14

Use of data collected by passive sensors often requires accurate measurements of solar radiation reaching the surface at the time the observations were made. This information allows for the correction of "atmospheric effects" and results in

data or images that are more representative of actual surface characteristics.

15

Remote sensing data are the recorded representation of

radiation reflected or emitted from an area or object

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When measuring the reflected or emitted energy, ..................... can be used

either imaging or nonimaging sensors

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Data from imaging sensors can be processed to produce

an image of an area, within which smaller parts of the sensor's whole view are resolved visually

18

Nonimaging sensors usually are

hand held devices

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Nonimaging sensors usually are hand held devices that

register only a single response value, with no finer resolution than the whole area viewed by the sensor

20

Nonimaging sensors usually are hand held devices that register only a single response value, with no finer resolution than the whole area viewed by the sensor, and therefore

no image can be made from the data

21

Nonimaging sensors usually are hand held devices that register only a single response value, with no finer resolution than the whole area viewed by the sensor, and therefore no image can be made from the data. These single values can be referred to as

a type of "point" data

22

These single values can be referred to as a type of "point" data, however some small area is typically involved depending on

the sensor's spatial resolution

23

Image and nonimage data each have particular uses. Nonimage data give information for

one specific (usually small) area or surface cover type

24

Nonimage data give information for one specific (usually small) area or surface cover type, and can be used to

characterize the reflectance of various materials occurring in a larger scene and to learn more about the interactions of electromagnetic energy and objects.

25

Image data provide an opportunity to look at

spatial relationships, object shapes, and to estimate physical sizes

26

Image data provide an opportunity to look at spatial relationships, object shapes, and to estimate physical sizes based on

the data's spatial resolution and sampling

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Image data are desirable when ............................. (such as ..............) is needed

spatial information
(mapped output)

28

Image data provide an opportunity to look at spatial relationships, object shapes, and to estimate physical sizes based on the data's spatial resolution and sampling. Image data are desirable when spatial information (such as mapped output) is needed. This text refers primarily to

imaging sensors and data.

29

Images produced from remote sensing data can be either

analog (such as a photograph) or digital (a multidimensional array or grid of numbers)

30

Digital data can be analyzed by

studying the values using calculations performed on a computer