List of Acronyms
1D | One-Dimensional |
2D | Two-Dimensional |
ALD | Azimuth Look Direction |
ALOS | Advanced Land Observing Satellite |
AMI | Active Microwave Instrument |
ASI | Agenzia Spaziale Italiana (Italian Space Agency) |
AVHRR | Advanced Very High Resolution Radiometer |
BTTB | Block-Toeplitz Toeplitz-Block |
CFE | Comisión Federal de Electricidad, Mexico |
CLARA’96 | Clouds and Radiation experiment 1996 |
CMOD4 | C-band Model 4 (empirically derived model function to relate normalized radar cross-section with wind speed and direction) |
CNES | Centre National D’Etudes Spatiales |
CPGF | Cerro Prieto Geothermal Field |
CSA | Canadian Space Agency |
CTRS | Conventional Terrestrial Reference System |
DEM | Digital Elevation Model |
DEOS | Delft Institute for Earth-Oriented Space Research |
DFD | Deutsches Fernerkundungsdatenzentrum (German Remote Sensing Data Center) |
DIAL | Differential Absorption Lidar |
DLR | Deutsches Zentrum für Luft- und Raumfahrt e.V. (German Aerospace Center) |
DPWV | Differential Precipitable Water Vapor |
DUT | Delft University of Technology |
ERS | European Remote Sensing Satellite |
ESA | European Space Agency |
fBm | Fractional Brownian Motion |
FFA | Far Field Approximation |
FFT | Fast Fourier Transform |
FM | Frequency Modulated |
GISARE | Groningen Interferometric SAR Experiment |
GNSS | Global Navigation Satellite Systems |
GPS | Global Positioning System |
IEEE | Institute of Electrical and Electronics Engineers |
IERS | International Earth Rotation Service |
IGS | International GPS Service for Geodynamics |
InSAR | Interferometric SAR / SAR interferometry |
IPW | Integrated Precipitable Water |
I/Q | In-Phase (real), Quadrature (imaginary) |
IRM | Interferometric Radar Meteorology |
ITRF | IERS Terrestrial Reference Frame |
JERS | Japanese Earth-Resources Satellite |
JPL | Jet Propulsion Laboratory |
LOS | Line of Sight |
LT | Local Time |
MCF | Minimal Cost Flow |
MIT | Massachusetts Institute of Technology |
MSC | Mesoscale Shallow Convection |
NAM | Nederlandse Aardolie Maatschappij B.V. |
NAP | Normaal Amsterdams Peil (Dutch vertical reference datum) |
NASA | National Aeronautics and Space Administration |
NASDA | National Aeronautics and Space Development Agency (Japan) |
NDVI | Normalized Differential Vegetation Index |
NOAA | National Oceanic and Atmospheric Administration |
PAF | Processing and Archiving Center |
Probability Density function | |
PLW | Precipitable Liquid Water |
PRARE | Precise Range and Rate Equipment |
PRF | Pulse Repetition Frequency |
PWV | Precipitable Water Vapor |
radar | Radio detection and ranging |
RAR | Real Aperture Radar |
RCS | Radar Cross Section |
RH | Relative Humidity |
RMS | Root Mean Square |
RRF | Range Reference Function |
SAR | Synthetic Aperture Radar |
s/c | Spacecraft |
SIR | Shuttle Imaging Radar, Spaceborne Imaging Radar |
SLAR | Side Looking Airborne Radar |
SLC | Single-Look Complex |
SLR | Satellite Laser Ranging / (Side Looking Radar) |
SNR | Signal-to-Noise Ratio |
SPOT | System Probatoire d’Observation de la Terre |
SRTM | Shuttle Radar Topography Mission |
SWST | Sampling Window Start Time |
TEC | Total Electron Content |
TECU | Total Electron Content Unit |
TID | Traveling Ionospheric Disturbance |
UTC | Universal Coordinated Time |
VLBI | Very Long Baseline Interferometry |
VTEC | Vertical Total Electron Content |
WGS84 | World Geodetic Survey 1984 |
WV | Water Vapor |
X-SAR | X-band Synthetic Aperture Radar |
List of Symbols
∅ | Initialization value, usually determined for reference surface |
A | Design matrix |
Aκ | Part of the design matrix corresponding to observation κ |
B | Baseline |
B∥ | Parallel baseline |
B⊥ | Perpendicular baseline |
B°⊥ | Perpendicular baseline for range to resolution cell on the reference surface |
B⊥crit | Critical (perpendicular) baseline |
Bℎ | Horizontal baseline |
Bᵛ | Vertical baseline |
Bᴬ | Azimuth time bandwidth |
Bᴿ | Range bandwidth |
Bᴰᵒᵖ | Doppler bandwidth |
ᶜ | Speed of light = 299792458 m/s |
C | Structure function coefficient |
C ẋ | Variance-covariance matrix of the estimated parameters |
Cφ | Variance-covariance matrix |
Cs | Variance-covariance matrix of atmospheric delay |
Dᵃ | Antenna width (m) |
D{.} | Dispersion operator, second moment, or variance-covariance matrix |
Dᵢ | Fractal dimension for a signal |
Dᵏ | Slant deformation for observation ᵏ |
Dχ | Structure function of parameter χ |
E{.} | Expectation operator, ensemble average, first moment, or mean |
ℯ | Partial pressure of water vapor (hPa) |
f | Frequency |
f o | Carrier (center) frequency |
fᴰ | Doppler frequency |
fᴰ c | Doppler centroid frequency |
fᵖ | Pulse repetition frequency (PRF) (cycles/m) |
f∮ | Fringe frequency |
ℎᵖ | Altitude of point ᵖ |
ℎꜱᵖ | Height of the sub-ionospheric point (m) |
ℎ ²π | Height ambiguity (m) |
H | Altitude; Haussdorff measure |
H κ | Topographic height for observation κ |
I | Integrated Precipitable Water |
κ | Wavenumber |
L | Effective number of looks |
Lα | Antenna length (m) |
L1,L2 | GPS carrier phase frequencies (Ll=l.57542 GHz, L2=l.22760 GHz) |
L3 | GPS ionospheric-free linear combination |
m | Number of observations |
n | Number of parameters (unknowns) |
nᵉ | Electron content (m-3) |
n∥ | Parallel error baseline |
n⊥ | Perpendicular error baseline |
N | Refractivity, Geoid height |
Probability density function | |
P | Total atmospheric pressure (hPa) |
P ᵡ | Power spectrum of parameter ᵡ |
Qφ | Real positive-semidefinite cofactor matrix |
R | (Slant) range (m) |
R1 | Slant range between reference (master) satellite and resolution cell (m) |
R2 | Slant range between secundary (slave) satellite and resolution cell (m) |
Sc | Chirp rate or Frequency slope ( S-2) |
STiK | Slant atmospheric delay for pixel at (m) |
t | Time (s) |
T | Temperature (K) |
υ | Velocity (m/s) |
υ | Hermitian product γ1γ2* |
υ s/c | Velocity of spacecraft (m/s) |
ᵚᵏ | Integer ambiguity number |
w | Liquid water content (g m-3) |
w{.} | Wrapping operator |
wᵃ | Radar footprint width in azimuth (3dB) |
x | Vector of parameters |
ẋ | Best linear unbiased estimator of the unknown parameters x |
Ẋs/c | State vector of spacecraft |
ỿᵢ | Complex observation (phasor) ᵢ |
Z(υ,v) | Amplitude spectrum of interferogram υ and v are wavenumbers) |
Z(υ,v) | Amplitude spectrum of filtered interferogram |
α | Baseline orientation angle; Spectral exponent |
β | Error baseline orientation angle; Spectral index |
βᵣ | Angular beamwidth in range direction (rad) |
βα | Angular beamwidth in azimuth direction (rad) |
γ | Coherence (complex) |
γgeom | Coherence reduction due to geometric (baseline) decorrelation |
γdc | Coherence reduction due to Doppler centroid decorrelation |
γtemporal | Coherence reduction due to temporal decorrelation |
γvol | Coherence reduction due to volume decorrelation |
γprocessing | Coherence reduction due to processing induced decorrelation |
γthermal | Coherence reduction due to thermal noise |
ℾᵪ | Semi-variogram of parameter ᵪ |
∂∅ | Change in look angle |
Δα | Focused azimuth resolution |
Δᵣ | Slant range resolution |
ΔR | Slant range difference |
ΔRdefo,p | Slant range difference due to deformation |
ℰ | Vector of observation errors |
ζ | Local terrain slope w.r.t. reference surface (positive towards the radar) ζ =∅inc-∅loc |
∅ | Look angle |
∅inc | Incidence angle, defined with respect to the global vertical at the scene |
∅loc | Local incidence angle, defined with respect to the local vertical at the ∅inc=∅loc-ζ |
ⱴ | Reference phase (rad) |
kN | 4π/⋋ |
⋋ | Radar wavelength |
Ʌ | Geographic longitude in WGS84 |
μ | Mean |
p | Local earth radius (m); Horizontal distance between two resolution cells. |
pχ | Autocorrelation function of parameter χ |
σ2 | a priori variance factor |
σ0 | “Sigma nought” or Radar Cross Section (RCS). Average power reflectivity or scattering coefficient per unit surface area |
τ | Pulse length |
τc | Effective pulse length |
∅ | Absolute interferometric phase, including reference phase |
∅w | Wrapped interferometric phase, including reference phase |
∅ | Geographic latitude in WGS84 |
∅r | Off-center beam angle in range direction (rad) |
∅a | Off-center beam angle in azimuth direction (rad) |
∅s | Squint angle (rad) |
∅N | Phase noise (rad) |
φ | Absolute interferometric phase, reference phase subtracted |
φw | Wrapped interferometric phase, reference phase subtracted |
φk | Stochastic phase observation |
φ | Real stochastic vector of observations |
ψ | Phase (rad) |
ψscat | Scattering contribution to the phase value (rad) |
Ωk | Ratio between of B⊥ deformation pair and of B⊥ topographic pair |
ℕ | Set of natural numbers |
ℝ | Set of real numbers |
ℤ | Set of integer numbers |
ℂ | Set of complex numbers |
ℱ | Fourier transform |