Technical documentation

class sense.model.CanopyHomoRT(ke_h: float, ke_v: float, ks_h: float, ks_v: float, d: float, theta: float | ndarray, stype: str)[source]

Bases: object

Homogeneous canopy RT model.

Assumes homogeneous vertical distribution of scatterers in that case the Lambert Beer law applies

NOTE that this model is only for BACKSCATTERING GEOMETRY!

Parameters:

ke_h (float) – volume extinction coefficient [Np/m]
ke_v (float) – volume extinction coefficient [Np/m]
d (float) – height of canopy layer [m]
theta (float, ndarray) – incidence angle [rad]

d: float

ke_h: float

ke_v: float

ks_h: float

ks_v: float

sigma_c()[source]

Calculate canopy volume contribution only.

Eq. 11.10 + 11.16 as seen in 11.17, Ulaby 2014

sigma_gcg(G_v, G_h)[source]

Calculate ground-canopy-ground interactions (Eq. 11.16, Ulaby 2014).

Parameters:

G_v (float) – v-polarized coherent Fresnel reflectivity under rough conditions see eq. 11.11 for explanations. As this depends on the surface model used, these should be provided here explicitely
G_h (float) – same as above, but for h-polarization.

stype: str

theta: float | ndarray

class sense.model.Ground(S: object, C: object, RT_s: str, RT_c: str, theta: float | ndarray, freq: float)[source]

Bases: object

Calculate the (attenuated) ground contribution sigma_pq.

p is receive and q is transmit polarization

Parameters:

S (object) – descibing the surface properties
C (object) – describing the canopy properties
RT_s (str) – key describing the surface scattering model
RT_c (str) – key specifying the canopy scattering model
theta (float/array) – incidence angle [rad]
freq (float) – frequency[GHz]

C: object

RT_c: str

RT_s: str

S: object

freq: float

sigma()[source]: Backscattering coefficient (Eq. 11.4, p.463 Ulaby 2014).

sigma_c_g(coherent=None)[source]

Calculate canopy ground scattering coefficient.

This is based on Eq. 11.17 (last term) in Ulaby (2014) and 11.14 in Ulaby (2014)

for co-pol, coherent addition can be made as an option

Parameters:: coherent (bool) – do coherent calculation for co-pol calculations

sigma_g_c_g()[source]: Calculate ground canopy ground scattering coefficient (Ulaby 2014).

theta: float | ndarray

class sense.model.Model(theta: float)[source]

Bases: object

Basic class for scattering modelling.

sigma0(dB: bool = False, pol: List[str] | None = None)[source]

Calculate sigma.

Parameters:

dB (bool) – Return results in decibel.
pol (list) – List with polarizations pq whereas p=receive, q=transmit p,g can be either H or V

theta: float

class sense.model.RTModel(theta: float, surface: object, canopy: object, models: Dict[str, str], freq: float, coherent: bool = True)[source]

Bases: Model

Radiative Transfer Models.

SSRT Eq. 11.17 (Ulaby and Long 2014) or WCM (Attema and Ulaby 1978).

Parameters:

surface (Surface description) – Object describing the surface
canopy (Canopy description) – Object describing the canopy
models (dict) – Dictionary with configuration of scattering models

canopy: object

coherent: bool = True

freq: float

models: Dict[str, str]

surface: object

class sense.model.WaterCloudCanopy(A_hh: float, B_hh: float, A_vv: float, B_vv: float, A_hv: float, B_hv: float, V1: float, V2: float, theta: float | ndarray)[source]

Bases: object

Water cloud model Attema and Ulaby (1978).

Canopy part

Parameters:

A (float) – fitting parameters
B (float) – fitting parameters
V1 (float) – vegetation descriptor
V2 (float) – vegetation descriptor
theta (float, ndarray) – incidence angle [rad]

A_hh: float

A_hv: float

A_vv: float

B_hh: float

B_hv: float

B_vv: float

V1: float

V2: float

sigma_c() → Dict[str, float | ndarray][source]: Calculate canopy backscatter part.

theta: float | ndarray

Definition of scatter types.

Bases: Scatterer

Isotropic scatterer definition (see Ulaby 2014, 11.2).

sigma_v_back()[source]

Volume backscattering coefficient for isotropic case.

This corresponds to the volume scattering coefficient ks. Note: This is NOT the scattering cross section of a single particle!

Returns:: Backscattering coefficients for ‘hh’, ‘vv’, ‘hv’.
Return type:: dict

sigma_v_bist()[source]: Bistatic volume backscatter (same as sigma_v_back (Eq. 11.19)).

Bases: Scatterer

Rayleigh scatterer definition (see Ulaby 2014, 11.2).

sigma_v_back()[source]

Volume backscattering coefficient for Rayleigh scatterers.

Returns:: Backscattering coefficients for ‘hh’, ‘vv’, ‘hv’. Note: ‘hv’ is undefined (np.nan).
Return type:: dict

sigma_v_bist()[source]: Bistatic volume backscatter (same as sigma_v_back (Eq. 11.22)).

Bases: object

Base class for scatterers.

Parameters:

sigma_s_hh (float) – Particle HH scattering cross section [m²].
sigma_s_vv (float) – Particle VV scattering cross section [m²].
sigma_s_hv (float) – Particle HV scattering cross section [m²].

sigma_s_hh: float | ndarray = None

sigma_s_hv: float | ndarray = None

sigma_s_vv: float | ndarray = None

Bases: object

Class specifying a soil.

Parameters:

surface (string) – name of used RT-model for surface contribution
eps (complex) – relative permitivity, if this is not given, then mv needs to be given
s (float) – surface rms height [m]
mv (float) – volumetric soil moisture [m**3/m**3]; either eps or mv needs to be given
f (float) – frequency [GHz]
l (float) – optional: autocorrelation length
acl (str) – identifier for shape of autocorrelation function G = Gaussian E = Exponential
clay (float) – optional fractional clay content
sand (float) – optional fraction sand content
bulk (float) – bulk density [g/cm**3]
C_hh (float) – empirical parameter (Water Cloud Model)
D_hh (float) – empirical parameter (Water Cloud Model)
C_vv (float) – empirical parameter (Water Cloud Model)
D_vv (float) – empirical parameter (Water Cloud Model)
C_hv (float) – empirical parameter (Water Cloud Model)
D_hv (float) – empirical parameter (Water Cloud Model)
V2 (float) – parameter specifying the vegetation (Water Cloud Model)

C_hh: float | None = None

C_hv: float | None = None

C_vv: float | None = None

D_hh: float | None = None

D_hv: float | None = None

D_vv: float | None = None

V2: float | None = None

acl: str | None = None

bulk: float | None = 1.65

clay: float | None = None

dc_model: str = 'Dobson85'

debye: float | None = None

eps: complex | None = None

f: float | None = None

k: float | None = None

kl: float | None = None

ks: float | None = None

l: float | None = None

mv: float | None = None

s: float | None = None

sand: float | None = None

surface: str | None = None

Module for some utilty functions.

sense.util.f2lam(f)[source]: Given the frequency in GHz, return the wavelength [m].

Specification of canopies.

Bases: object

Define a homogeneous one layer canopy.

Right now water_cloud and turbid_isotropic/turbid_rayleigh are implemented

A_hh: float | None = None

A_hv: float | None = None

A_vv: float | None = None

B_hh: float | None = None

B_hv: float | None = None

B_vv: float | None = None

V1: float | None = None

V2: float | None = None

canopy: str

d: float | None = None

ke_h: float | None = None

ke_v: float | None = None

ks_h: float | None = None

ks_v: float | None = None

class sense.dielectric.dobson85.Dobson85(clay: float | None = None, sand: float | None = None, mv: float | None = None, freq: float | ndarray | None = None, bulk: float = 1.65, temp: float = 23.0, debye: bool = False, single_debye: bool = False)[source]

Bases: EpsModel

Dielectric mixing model for soils After Dobson et al. (1985).

Coding after Ulaby (2014), Chapter 4

debye: bool = False

single_debye: bool = False

Bases: object

Generic model for dielectric mixing models.

bulk: float = 1.65

clay: float | None = None

freq: float | ndarray | None = None

mv: float | None = None

sand: float | None = None

temp: float = 23.0

Bases: object

Major surface scatter class.

C_hh: float = None

C_hv: float = None

C_vv: float = None

D_hh: float = None

D_hv: float = None

D_vv: float = None

eps: complex | ndarray = None

kl: float = None

ks: float = None

mv: float | ndarray = None

theta: float | ndarray = None