ISO/TS 19159-3:2018 地理情報—リモートセンシング画像センサーとデータのキャリブレーションと検証—パート3：SAR / InSAR | ページ 6

3.1

accuracy

closeness of agreement between a test result or measurement result and the true value

Note 1 to entry: In this document, the true value can be a reference value that is accepted as true.

[SOURCE:ISO 3534‑2:2006, 3.3.1, modified — NOTES 1, 2 and 3 have been deleted. New Note 1 to entry has been added.]

3.2

antenna pattern

ratio of the electronic-field strength radiated in the direction θ to that radiated in the beam-maximum direction

3.3

aperture reference point

ARP

3D location of the centre of the synthetic aperture

Note 1 to entry: It is usually expressed in ECEF coordinates in metres.

[SOURCE:ISO/TS 19130:2010, 4.4]

3.4

attitude

orientation of a body, described by the angles between the axes of that body’s coordinate system and the axes of an external coordinate system

[SOURCE:ISO 19116:2004 4.2]

3.5

azimuth resolution

<SAR> resolution in the cross-range direction

Note 1 to entry: This is usually measured in terms of the impulse response of the SAR sensor and processing system. It is a function of the size of the synthetic aperture, or alternatively the dwell time (e.g. larger aperture → longer dwell time → better resolution).

Note 2 to entry: 3 dB width of the impulse response is the normal value of measurements.

Note 3 to entry: Cross-range direction is also the same as along-track direction.

[SOURCE:ISO/TS 19130:2010, 4.7, modified — Notes 2 and 3 to entry have been added.]

3.6

backscattering coefficient

average radar cross section per unit area

Note 2 to entry: “Backscattering coefficient” is sometimes called “normalized radar cross section”.

3.7

calibration

process of quantitatively defining a system’s responses to known, controlled signal inputs

[SOURCE:ISO/TS 19101‑2: 2008, 4.2]

3.8

calibration coefficient

ratio of SAR image pixel power to radar cross section without considering additive noise, after the processor gain is normalized to one, and elevation antenna pattern, range and atmospheric attenuation are all corrected

3.9

correction

compensation for an estimated systematic effect

Note 1 to entry: See ISO/IEC Guide 98-3:2008, 3.2.3, for an explanation of “systematic effect”.

Note 2 to entry: The compensation can take different forms, such as an addend or a factor, or can be deduced from a table.

[SOURCE:ISO/IEC Guide 99:2007, 2.53]

3.10

cross-talk

any signal or circuit unintentionally affecting another signal or circuit

Note 1 to entry: For PolSAR sensor, if the transmitting channel is horizontally (H) polarized, the cross-talk on transmitting defines the ratio of V polarization transmitting power to H polarization transmitting power, expressed in decibels (dB). The cross-talk on receiving is similar to that on transmitting.

3.11

digital elevation model

DEM

dataset of elevation values that are assigned algorithmically to 2-dimensional coordinates

[SOURCE:ISO/TS 19101‑2:2008, 4.5]

3.12

height

h, H

distance of a point from a chosen reference surface measured upward along a line perpendicular to that surface

Note 1 to entry: A height below the reference surface will have a negative value.

Note 2 to entry: The terms elevation and height are synonyms.

[SOURCE:ISO 19111:2007, 4.29 — modified: Note 2 to entry has been added.]

3.13

incident angle

vertical angle between the line from the detected element to the sensor and the local surface normal (tangent plane normal)

[SOURCE:ISO/TS 19130:2010, 4.57]

3.14

interferometric baseline

distance between the two antenna phase centre vectors at the time when a given scatterer is imaged

3.15

integrated side lobe ratio

ISLR

ratio between the side lobe power and the main lobe power of the impulse response of point targets in the radar imaging scene

3.16

interferometric synthetic aperture radar

InSAR

technique exploiting two or more SAR images to generate maps of surface deformation or digital elevation through the differences in the phase of the waves returning to the radar

3.17

look angle

vertical angle from the platform down direction to the slant range direction, usually measured at the aperture reference point (ARP)

Note 1 to entry: “Off-nadir angle” has the same definition as “look angle”.

[SOURCE:ISO/TS 19130‑2:2014, 4.42, modified — new Note 1 to entry has replaced the original Note 1 to entry.]

3.18

metadata

information about a resource

[SOURCE:ISO 19115‑1:2014, 4.10]

3.19

peak side lobe ratio

PSLR

ratio between the peak power of the largest side lobe and the peak power of the main lobe of the impulse response of point targets in the SAR image

3.20

polarimetric synthetic aperture radar

SAR sensor enhanced by transmitting and receiving in different combinations of polarization

Note 1 to entry: By combining multiple polarization modes, it is possible to characterize the target more clearly. Quad-Pol SAR system both transmits and receives orthogonal (e.g. horizontal and vertical) polarizations, which creates four polarizations of a single imaging scene. The calibration of Quad-Pol SAR is addressed in this document.

3.21

polarization channel imbalance

bias in the estimation of the scattering matrix element ratio between coincident pixels from two coherent data channels

Note 1 to entry: Polarization channel imbalance includes the amplitude imbalance and phase imbalance.

3.22

pulse repetition frequency

number of times the system (e.g. LIDAR) emits pulses over a given time period, usually stated in kilohertz (kHz)

[SOURCE:ISO/TS 19130‑2:2014, 4.53]

3.23

radar cross section

measure of the capability of the object to scatter the transmitted radar power

3.24

range

<SAR> distance between the antenna and a distant object, synonymous with slant range

[SOURCE:ISO/TS 19130‑2:2014, 4.54]

3.25

range bin

<SAR> group of radar returns that all have the same range

[SOURCE:ISO/TS 19130:2010, 4.69]

3.26

range direction

slant range direction

<SAR> direction of the range vector

[SOURCE:ISO/TS 19130:2010, 4.70]

3.27

range resolution

spatial resolution in the range direction

Note 1 to entry: For a SAR sensor, it is usually measured in terms of the impulse response of the sensor and processing system. It is a function of the bandwidth of the pulse.

Note 2 to entry: 3 dB width of the impulse response is the normal value of measurements.

[SOURCE:ISO/TS 19130:2010, 4.71 — modified: Added Note 2 to entry.]

3.28

remote sensing

collection and interpretation of information about an object without being in physical contact with the object

[SOURCE:ISO/TS 19101‑2:2008, 4.33]

3.29

resolution (of imagery)

smallest distance between two uniformly illuminated objects that can be separately resolved in an image

Note 1 to entry: This definition refers to the spatial resolution.

Note 2 to entry: In the general case, the resolution determines the possibility to distinguish between neighbouring features (objects).

Note 3 to entry: Resolution can also refer to the spectral and the temporal resolution.

[SOURCE:ISO/TS 19130‑2:2014, 4.61 — modified: Added Notes 1, 2 and 3 to entry.]

3.30

scattering matrix

matrix characterizing the scattering process at the target of interest for polarimetric SAR

3.31

sensor

element of a measuring system that is directly affected by a phenomenon, body, or substance carrying a quantity to be measured

Note 1 to entry: Active or passive sensors exist. Often two or more sensors are combined to a measuring system.

[SOURCE:ISO/IEC Guide 99:2007, 3.8 — modified: The EXAMPLE and NOTE were replaced by Note 1 to entry.]

3.32

uncertainty

parameter, associated with the result of measurement, that characterizes the dispersion of values that could reasonably be attributed to the measurand

Note 1 to entry: The parameter may be, for example, a standard deviation (or a given multiple of it), or the half-width of an interval having a stated level of confidence.

Note 2 to entry: Uncertainty of measurement comprises, in general, many components. Some of these components may be evaluated from the statistical distribution of the results of series of measurements and can be characterized by experimental standard deviations. The other components, which can also be characterized by standard deviations, are evaluated from assumed probability distributions based on experience or other information.

Note 3 to entry: It is understood that the result of the measurement is the best estimate of the value of the measurand, and that all components of uncertainty, including those arising from systematic effects, such as components associated with corrections and reference standards, contribute to the dispersion.

Note 4 to entry: When the quality of accuracy or precision of measured values, such as coordinates, is to be characterized quantitatively, the quality parameter is an estimate of the uncertainty of the measurement results. Because accuracy is a qualitative concept, one should not use it quantitatively, that is associate numbers with it; numbers should be associated with measures of uncertainty instead.

Note 5 to entry: Measurement uncertainty includes components arising from systematic effects, such as components associated with corrections and the assigned quantity values of measurement standards, as well as the definitional uncertainty. Sometimes estimated systematic effects are not corrected for but, instead, associated measurement uncertainty components are incorporated.

Note 6 to entry: The parameter may be, for example, a standard deviation called standard measurement uncertainty (or a specified multiple of it), or the half-width of an interval, having a stated coverage probability.

Note 7 to entry: Measurement uncertainty comprises, in general, many components. Some of these may be evaluated by Type A evaluation of measurement uncertainty from the statistical distribution of the quantity values from series of measurements and can be characterized by standard deviations. The other components, which may be evaluated by Type B evaluation of measurement uncertainty, can also be characterized by standard deviations, evaluated from probability density functions based on experience or other information.

Note 8 to entry: In general, for a given set of information, it is understood that the measurement uncertainty is associated with a stated quality value attributed to the measurand. A modification of this value results in a modification of the associated uncertainty.

[SOURCE:ISO 19116:2004, 4.26 modified: Added Notes 1, 2, 3, 5, 6, 7 and 8 to entry.]

3.33

validation

process of assessing, by independent means, the quality of the data products derived from the system outputs

Note 1 to entry: In this document, the term validation is used in a limited sense and only relates to the validation of calibration data in order to control their change over time.

[SOURCE:ISO/TS 19101‑2:2008, 4.41]