Final Flashcards

1
Q

What does satellite data offer?

A

cost-effective, timely, transparent, information on crop type, plant health, stress, and productivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are early forecasts?

A

Critical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Crop Monitor for AMIS

A

develop transparent, timely, crop condition assessments in primary agricultural production areas highlighting potential hotspots of stress/ bumper crops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

NASA’s Earth Observation for Food Security and Agriculture Consortium

A

increase food security awareness and understand of the applications of NASA’s and other satellite data products by users from a wide range of sectors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Major tasks of (4)

A

crop state assessment
crop yield assessment/ forecasting
crop type mapping
crop area estimation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Biophysical Parameters

A

total canopy chlorophyll, vegetation fraction, fraction of photosynthetically active radiation absorbed by photosyhntetically active vegetation, green leaf area index, gross primary production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

information retrieval

A

spatial: courier transformation
spectral: spectral curvatures
Temporal: change detection, temporal profiles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Spectral curve of plants

A

typical vegetation reflectance curve with dominant factors controlling leaf reflectance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

spectral curve of plants:PROSPECT

A

radiative transfer model that represents the optical properties of plant leaves from 400nm to 2500nm

simulates spectra based on input parameters of the plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

inverse problem

A

to estimate properties of the plants based on the given spectra

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Chlorophyll content

A

relates closely to the crop primary production and is a good indicator of the physiological status and the carbon sequestration potential of crops, it is also a good predictor of crop yield

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Vegetation fraction

A

defined as the percentage or fraction of occupation occupation of vegetation canopy in a given ground area in vertical projection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Leaf Area Index

A

the ratio of the one-sided green leaf area to the ground area underneath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Fraction of Absorbed Photosynthetically Active Radiation

A

influences vegetation production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Gross Primary Production

A

vegetation productivity is the basis of all the biosphereic functions on the land surface and is simply defined as the production of organic matter through photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Crop type mapping

A

classification of multi-temporal multi-spectral satellite images into crop-related classes

cropland vs non-cropland

training/ calibration data: ground truth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

soil moisture

A

soil moisture is the water that is held in the space between soil particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does soil moisture depend on

A

soil properties
topography
presence/ absence of vegetation
the frequency and amount of precipitation/ irrigation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

soil moisture

A

SMAP: soil moisture Active Passive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the mapping key parameters from remote sensing?

A

Land surface albedo
downward shortwave radiation
land surface temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the determine factors for remote sensing?

A

surface- reflectance, emissivity, and temperature
Atmosphere

22
Q

what are sensor characteristics?

A

Wavelength- spectral signature
view geometry- angular signature
polarization etc

23
Q

inversion problem

A

Underdetermined
Ill-posed/ improperly posed problem

24
Q

Albedo

A

ratio between reflected solar radiation and incident solar radiation

25
Q

What direction in albedo in?

A

all directions and it is broadbanded

26
Q

What direction is RS signature in?

A

One direction
Narrow banded

27
Q

BRDF what does it stand for?

A

Bi-directional Reflectance Distribution Function

28
Q

What is BRDF

A

Ratio of incremental radiance, leaving surface through an infinitesimal solid angle in direction to incremental irradiance from illumination direction

29
Q

How are BDRF and albedo related?

A

Albedo depends on BRDF and incident angle

30
Q

BRDF modeling in…

A

radiative transfer models: physical explanation
canopy/ soil parameters

empirical models

empirical models: kernel-driven models

31
Q

Albedo Retrieval approaches

A

BDRF fittings, optimization, direct estimation, and BRDF database

32
Q

What are needed for BDRF fittings?

A

Multiangular RS data: MISR, POLDER
3 observations
temporal composite approach- assume no surface change

33
Q

to measure BRDF via RS you need?

A

multiple cameras on same platform
ex: multi-angle imaging spectroRadiometer

broad swath with large overlap so multiple orbits build up multiple view angles

Pointing capability: offers an oblique viewing capacity, the viewing angle is adjustable through 27 degrees off vertical

34
Q

Issues of BRDF fitting approach

A

error propagation
unable to capture rapidly changing albedo
large errors over snow albedo

35
Q

Unique features of NOAAs VIIRS land surface albedo product

A

high accuracy, gap-free, high temporal resolution, daily mean value

36
Q

Incident Solar Radiation

A

aka insolation
300nm - 3000nm
drives longwave emission, latent and sensible heat fluxes
one of the key parameters in earth surface radiation budget

37
Q

Photosynthetically active radiation

A

400nm-700nm
an essential input for most of the ecosystem models
important for quantifying earth’s carbon cycle

38
Q

Radiation transfer modeling

A

accuracy dependent on quality of input data
requiring inputs of atmospheric and surface parameters
computationally expensive

39
Q

Parameterization

A

approximation of RT models
Efficient

40
Q

Summary of forward methods

A

highly accurate when high quality atmospheric input variables are available

41
Q

Innovative LUT-based method

A

accurate and efficient
Directly use TOA radiance data
improved spatial resolution

two parameterization schemes
TOA radiance and Surface flux

Parameters are pre-calculated from accurate MODTRAN

42
Q

Steps of the algorithm using temporal signatures

A

a set of temporal observations for each pixel
covert blue-band TOA radiance to “surface reflectance” using a default clear atmosphere
identify a set of “clear” observations with the minimum blue-band reflectance
interpolate surface reflectance of other observations
interpolate surface reflectance of other observations

43
Q

Algorithm integration

A

individual retrieval methods have strengths and limitations

using machine learning methods to combine multiple retrieval algorithms

44
Q

Skin temperature retrieval approaches

A

sea surface temperature vs. land surface temperature
single channel algorithm
two channel algorithm

45
Q

q

A
46
Q

qq

A
47
Q

q

A
48
Q

q

A
49
Q

q

A
50
Q

q

A