Remote Sensing Midterm

Front 1

radiometer

Back 1

measures the radiant flux of electromagnetic radiation as thermal and photodiode

Hint 1

radiant flux

Front 2

frame sensor

Back 2

produces digital images with the use of detectors that measure the brightness of reflected electromagnetic energy

Hint 2

digital, brightness

Front 3

line sensor (pushbroom scanner)

Back 3

a device whose sensors are lined up in a row called a linear array; captures the entire scan line at once

Hint 3

linear array

Front 4

mechanical sensor (whiskbroom scanner)

Back 4

device which uses rotating mirrors to scan the landscape below from side to side, perpendicular to the direction of the sensor platform

Hint 4

rotating mirrors

Front 5

modulation transfer function

Back 5

measure of the transfer of contrast from the subject to the image; measures how faithfully the lens reproduces detail from the object to the image

Hint 5

transfer; faithfully reproduces detail

Front 6

silicon detector

Back 6

type of photoconductor detector used in most commercial photodiodes with a visible spectral range, ambient operating temperature

Front 7

InGaAs

Back 7

Indium Gallium Arsenide detector with NIR and SWIR spectral range used in high-power and high-frequency electronics because of its superior electron velocity

Hint 7

high-power, high-frequency, electron velocity

Front 8

Mercad telluride

Back 8

Mercury Cadium Telluride detector; longwave (thermal) radiation spectral range; very high temperature operation, used in military

Front 9

point spread function

Back 9

describes the response of an imaging system to a point source or point object; the extended blob in an image that represents an unresolved object

Hint 9

response; extended blob

Front 10

sun's declination

Back 10

the angle between the rays of the sun and the earth's equator; varies with the season and its period is 1 year

Front 11

ephemeris meridian

Back 11

fictitious meridian that rotates independently of the earth at the uniform rate defined by Terrestrial Dynamical Time

Front 12

ephemeris transit

Back 12

the passage of the sub-solar point over the ephemeris meridian; varies from 11:45 to 12:13 depending on time of year

Front 13

geosynchronous orbit

Back 13

orbit around the Earth with period matching the sidereal rotation period; a satellite in such an orbit returns to exactly the same place in the sky at exactly the same time each day

Hint 13

sidereal

Front 14

sun-synchronous orbit

Back 14

geocentric orbit which combines altitude and inclination in such a way that an object on that orbit passes over any given point of the Earth's surface at the same local solar time

Hint 14

combines altitude and inclination; same local solar time

Front 15

nodal day

Back 15

period of the earth-rotation relative to the orbit plane or node

Front 16

precession

Back 16

rotation of the orbit plane about the polar axis caused by the oblateness of the Earth

Front 17

wavelength

Back 17

distance between repeating units of a propagating wave of a given frequency; denoted by lambda

Front 18

frequency

Back 18

a number of cycles, or periods, per unit time

Front 19

polarization

Back 19

a property of waves that describes the orientation of their oscilllation

Hint 19

orientation

Front 20

blackbody

Back 20

an object that absorbs all light that falls on it; no electromagnetic radiation passes through it and none is reflected

Front 21

Lambert's Law

Back 21

the radiant intensity observed from a Lambertian surface is directly proportional to the cosine of the angle between the observer's line of sight and the surface normal

Front 22

Lambertian surface

Back 22

a perfectly diffusing surface; its brightness is constant regardless of the angle from which it is viewed

Front 23

scattering

Back 23

process whereby some forms of radiation, such as light, are forced to deviate from a straight trajectory by one or more uniformities in the medium through which they pass

Hint 23

deviate from straight, uniformities

Front 24

Rayleigh scattering

Back 24

process in which EM radiation is scattered by a small spherical volume of variant refractive index

Front 25

absorption

Back 25

process by which the energy of a photon is taken up by matter,

Front 26

attenuation

Back 26

the gradual loss in intensity of any kind of flux through a medium

Front 27

emission

Back 27

process by which the energy of a photon is released by another entity

Front 28

Mie scattering

Back 28

scattering of EM radiation by spherical particles which are generally larger than the Rayleigh range

Front 29

multiple scattering

Back 29

scattering of EM radiation in which the randomness of the interaction is averaged out by large numbers of scattering events, such that the final path of the radiation is a deterministic distribution of intensity

Hint 29

randomness averaged out by large numbers, final path dd of intensity

Front 30

radiative transfer equation

Back 30

a beam of light loses energy through divergence and extinction and gains energy from light sources in the medium and scattering directed toward the beam

Hint 30

loses energy - divergence, extinction; gains energy - light sources, scattering

Front 31

Beer-Lambert Law

Back 31

there is a logarithmic dependence between the transmission of light through a substance and the product of the absorption coefficient and the distance the light travels through the material

Hint 31

log btw T and abs. coeff. * distance

Front 32

astronomical unit

Back 32

mean Earth-Sun distance

Front 33

speed of light in a vacuum

Back 33

distance light travels in a vacuum during a given period of time

Front 34

spectral emissivity

Back 34

ratio of energy radiated by a material to energy radiated by a blackbody at equal temperature

Front 35

index of refraction

Back 35

how much the speed of light is reduced inside of a medium

Front 36

radiant flux

Back 36

flow rate of energy

Front 37

irradiance

Back 37

power incident on a surface

Front 38

exitance

Back 38

power emitted from a surface

Front 39

steradian

Back 39

SI unit of solid angle

Front 40

radiant intensity

Back 40

energy flowing outward from a point

Front 41

radiance

Back 41

power per unit solid angle per unit projected source area

Front 42

extinction coefficient

Back 42

K_e; the fraction of radiation taken from a direct beam by an aerosol

Front 43

optical thickness

Back 43

the depth of a material or medium in which the intensity of light of a given frequency is reduced by a factor of 1/e

Hint 43

depth reduced

Front 44

transmissivity

Back 44

the fraction of incident light at a specified wavelength that passes through a sample

Hint 44

EBOA/ETOA

Front 45

phase function

Back 45

P(theta); describes the angular distribution of scattered radiation

Front 46

single scattering albedo

Back 46

ratio of scattering efficiency to total light extinction

Hint 46

scattering coeff / extinction coeff

Front 47

specular reflection

Back 47

perfect, mirror-like reflection from a surface

Front 48

BRDF

Back 48

bidirectional reflectance distribution function; describes scattering of a parallel beam of incident light from one direction in the hemisphere to another

Hint 48

scattering incident one dir. to another

Front 49

BRF

Back 49

bidirectional reflectance factor; ratio of reflected flux from the surface area in a particular direction to the reflected flux from an ideal (Lambertian) surface

Hint 49

flux SA / flux Lamb. surf.

Front 50

HDRF

Back 50

hemispherical-directional reflectance factor; BRF, except illumination is allowed from the entire upper hemisphere

Front 51

DHR

Back 51

directional-hemispherical reflectance; reflectance of a surface under direct illumination (black sky albedo)

Hint 51

direct, BSA

Front 52

BHR

Back 52

bi-hemispherical reflectance; reflectance of a surface under diffuse illumination (white sky albedo)

Hint 52

diffuse, WSA

Front 53

albedo

Back 53

fraction of the incident light that is reflected from a surface

Hint 53

M / E