Final

Question 1

What does satellite data offer?

Answer 1

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

Question 2

What are early forecasts?

Answer 2

Critical

Question 3

Crop Monitor for AMIS

Answer 3

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

Question 4

NASA’s Earth Observation for Food Security and Agriculture Consortium

Answer 4

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

Question 5

Major tasks of (4)

Answer 5

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

Question 6

Biophysical Parameters

Answer 6

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

Question 7

information retrieval

Answer 7

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

Question 8

Spectral curve of plants

Answer 8

typical vegetation reflectance curve with dominant factors controlling leaf reflectance

Question 9

spectral curve of plants:PROSPECT

Answer 9

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

simulates spectra based on input parameters of the plants

Question 10

inverse problem

Answer 10

to estimate properties of the plants based on the given spectra

Question 11

Chlorophyll content

Answer 11

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

Question 12

Vegetation fraction

Answer 12

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

Question 13

Leaf Area Index

Answer 13

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

Question 14

Fraction of Absorbed Photosynthetically Active Radiation

Answer 14

influences vegetation production

Question 15

Gross Primary Production

Answer 15

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

Question 16

Crop type mapping

Answer 16

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

cropland vs non-cropland

training/ calibration data: ground truth

Question 17

soil moisture

Answer 17

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

Question 18

what does soil moisture depend on

Answer 18

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

Question 19

soil moisture

Answer 19

SMAP: soil moisture Active Passive

Question 20

What are the mapping key parameters from remote sensing?

Answer 20

Land surface albedo
downward shortwave radiation
land surface temperature

Question 21

What are the determine factors for remote sensing?

Answer 21

surface- reflectance, emissivity, and temperature
Atmosphere

Question 22

what are sensor characteristics?

Answer 22

Wavelength- spectral signature
view geometry- angular signature
polarization etc

Question 23

inversion problem

Answer 23

Underdetermined
Ill-posed/ improperly posed problem

Question 24

Albedo

Answer 24

ratio between reflected solar radiation and incident solar radiation

Question 25

What direction in albedo in?

Answer 25

all directions and it is broadbanded

Question 26

What direction is RS signature in?

Answer 26

One direction Narrow banded

Question 27

BRDF what does it stand for?

Answer 27

Bi-directional Reflectance Distribution Function

Question 28

What is BRDF

Answer 28

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

Question 29

How are BDRF and albedo related?

Answer 29

Albedo depends on BRDF and incident angle

Question 30

BRDF modeling in...

Answer 30

radiative transfer models: physical explanation canopy/ soil parameters empirical models empirical models: kernel-driven models

Question 31

Albedo Retrieval approaches

Answer 31

BDRF fittings, optimization, direct estimation, and BRDF database

Question 32

What are needed for BDRF fittings?

Answer 32

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

Question 33

to measure BRDF via RS you need?

Answer 33

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

Question 34

Issues of BRDF fitting approach

Answer 34

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

Question 35

Unique features of NOAAs VIIRS land surface albedo product

Answer 35

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

Question 36

Incident Solar Radiation

Answer 36

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

Question 37

Photosynthetically active radiation

Answer 37

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

Question 38

Radiation transfer modeling

Answer 38

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

Question 39

Parameterization

Answer 39

approximation of RT models Efficient

Question 40

Summary of forward methods

Answer 40

highly accurate when high quality atmospheric input variables are available

Question 41

Innovative LUT-based method

Answer 41

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

Question 42

Steps of the algorithm using temporal signatures

Answer 42

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

Question 43

Algorithm integration

Answer 43

individual retrieval methods have strengths and limitations using machine learning methods to combine multiple retrieval algorithms

Question 44

Skin temperature retrieval approaches

Answer 44

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

Question 45

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Question 46

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Question 47

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Question 48

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Question 49

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Question 50

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