chapter 3 sensors and platforms part 2 p2 Flashcards Preview

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Flashcards in chapter 3 sensors and platforms part 2 p2 Deck (31)
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1

Passive microwave systems are based on a ....................... that detects wavelengths in the .................. region of the spectrum

type of radiometer
microwave

2

Passive microwave systems are based on a type of radiometer that detects wavelengths in the microwave region of the spectrum. Because of the nature of microwave radiation

optical systems cannot be used for the detection of this range of wavelengths

3

Passive microwave systems are based on a type of radiometer that detects wavelengths in the microwave region of the spectrum. Because of the nature of microwave radiation, optical systems cannot be used for the detection of this range of wavelengths. As with optical systems though, both ........................ systems are available

nonimaging and imaging

4

The components of a microwave radiometer are

an antenna, receiver, and recording device

5

Microwave energy emitted from Earth's surface is collected by

an antenna

6

Microwave energy emitted from Earth's surface is collected by an antenna, converted by........................ into a ........................

a receiver into a signal

7

Microwave energy emitted from Earth's surface is collected by an antenna, converted by a receiver into a signal, and

recorded.

8

The features of electromagnetic energy measured by microwave radiometers are

polarity, wavelength, and intensity

9

The features of electromagnetic energy measured by microwave radiometers are polarity, wavelength, and intensity. These properties provide useful information about

the structure and composition of an object

10

Most of the applications of passive microwave radiometers have been in

the fields of atmospheric and oceanographic research

11

Most of the applications of passive microwave radiometers have been in the fields of atmospheric and oceanographic research. It has also proven to be an effective tool for the measurement of

soil moisture, an important parameter in studying vegetation

12

By combining a number of detectors or radiometers into ......................., it is possible to create a sensor that

detector arrays
can acquire a 2D image of an area

13

There are three basic designs for imaging sensors

frame, pushbroom, and mechanical scanner.

14

The first two designs are

similar.

15

The frame sensor is a 2D array of detectors that acquires an entire image in

one exposure

16

The first two designs are similar. The frame sensor is a ............ array of detectors that acquires an entire image in one exposure similar to the way

2D
a camera captures an image on film

17

A pushbroom sensor is a ........... . array that obtains

1D
an image one line at a time

18

A pushbroom sensor is a 1D array that obtains an image one line at a time. Each new data line is added as the platform

moves forward

19

Each new data line is added as the platform moves forward, building up

an image over time

20

. A pushbroom sensor is a 1D array that obtains an image one line at a time. Each new data line is added as the platform moves forward, building up an image over time. In a mechanical scanner system the sensor acquires

only one or several pixels in any given instant

21

In a mechanical scanner system the sensor acquires only one or several pixels in any given instant, but since the scanner

physically sweeps or rotates the sensor (a radiometer) or a mirror back and forth, an image is produced.

22

This category of sensor (...........................)

passive visible, infrared and thermal imaging systems

23

This category of sensor (passive visible, infrared and thermal imaging systems) contains .............................that have been deployed on

numerous instruments
a wide variety of platforms

24

This category of sensor (passive visible, infrared and thermal imaging systems) contains numerous instruments that have been deployed on a wide variety of platforms and used for

many applications

25

Most modern imaging systems are

multispectral (acquiring data for more than one limited spectral area)

26

The recording of each discrete spectral sampling is referred to as

an image band or channel.

27

Using image processing techniques, multiple (usually ............) bands selected from a

three
multispectral image database

28

Using image processing techniques, multiple (usually three) bands selected from a multispectral image database can be combined to make

a single color composite image

29

Active systems supply their own illumination energy which can be

controlled

30

Some advantages active systems have over passive sensors are they

do not require solar illumination of surfaces or perfect weather conditions to collect useful data