Package SatStress :: Module SatStress :: Class Diurnal
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Class Diurnal

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object --+    
         |    
 StressDef --+
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            Diurnal

An object defining the stress field that arises on a satellite due to an eccentric orbit.

Diurnal is a subclass of StressDef. See the derivation and detailed discussion of this stress field in in Wahr et al. (2008).

Instance Methods
NSR
__init__(self, satellite)
Sets the object's satellite and omega attributes; calculates Love numbers.
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float
Ttt(self, theta, phi, t)
Calculates the τ_θθ (north-south) component of the stress tensor.
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float
Tpp(self, theta, phi, t)
Calculates the τ_φφ (east-west) component of the stress tensor.
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float
Tpt(self, theta, phi, t)
Calculates the τ_φθ (off-diagonal) component of the stress tensor.
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Inherited from object: __delattr__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __repr__, __setattr__

    Inherited from StressDef
float
Delta(self, layer_n=-1)
Calculate Δ, a measure of how viscous the layer's response is.
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complex
Gamma(self)
Calculate the coefficient capital Gamma twiddle for the surface layer (see Wahr et al.
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float
Z(self)
Calculate the value of Z, a constant that sits in front of many terms in the potential defined by Wahr et al.
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__str__(self)
Output information about this stress field, including frequency dependent parameters.
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complex
alpha(self)
Calculate the coefficient alpha twiddle for the surface layer (see Wahr et al.
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complex
b1(self)
Calculate the coefficient beta one twiddle for the surface layer (see Wahr et al.
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complex
b2(self)
Calculate the coefficient beta two twiddle for the surface layer (see Wahr et al.
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calcLove(self)
Calculate the Love numbers for the satellite and the given forcing.
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calcLoveInfinitePeriod(self)
Return a set of zero Love numbers constructed statically.
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calcLoveWahr4LayerExternal(self)
Use John Wahr's Love number code to calculate h, k, and l.
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forcing_period(self)
Calculate the forcing period based on the forcing frequency (omega).
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complex
g1(self)
Calculate the coefficient gamma one twiddle for the surface layer (see Wahr et al.
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complex
g2(self)
Calculate the coefficient gamma two twiddle for the surface layer (see Wahr et al.
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complex
lambda_twiddle(self, layer_n=-1)
Calculate the frequency-dependent Lame parameter λ for a Maxwell rheology.
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complex
mu_twiddle(self, layer_n=-1)
Calculate the frequency-dependent Lame parameter μ for a Maxwell rheology.
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Class Variables
    Inherited from StressDef
LoveNum love = LoveNum(0, 0, 0, 0, 0, 0)
the Love numbers which result from the given forcing frequency and the specified satellite structure.
float omega = 0.0
the forcing frequency associated with the stress.
Satellite satellite = None
the satellite which the stress is being applied to.
Properties

Inherited from object: __class__

Method Details

__init__(self, satellite)
(Constructor)

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Sets the object's satellite and omega attributes; calculates Love numbers.

Parameters:
  • satellite (Satellite) - the satellite to which the stress is being applied.
Returns: NSR
an object defining the NSR stresses for a particular satellite.
Overrides: object.__init__

Ttt(self, theta, phi, t)

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Calculates the τ_θθ (north-south) component of the stress tensor.

Parameters:
  • theta - the co-latitude of the point at which to calculate the stress [rad].
  • phi - the east-positive longitude of the point at which to calculate the stress [rad].
  • t - the time, in seconds elapsed since pericenter, at which to perform the stress calculation [s].
Returns: float
the τ_θθ component of the 2x2 membrane stress tensor.
Overrides: StressDef.Ttt

Tpp(self, theta, phi, t)

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Calculates the τ_φφ (east-west) component of the stress tensor.

Parameters:
  • theta - the co-latitude of the point at which to calculate the stress [rad].
  • phi - the east-positive longitude of the point at which to calculate the stress [rad].
  • t - the time, in seconds elapsed since pericenter, at which to perform the stress calculation [s].
Returns: float
the τ_φφ component of the 2x2 membrane stress tensor.
Overrides: StressDef.Tpp

Tpt(self, theta, phi, t)

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Calculates the τ_φθ (off-diagonal) component of the stress tensor.

Parameters:
  • theta - the co-latitude of the point at which to calculate the stress [rad].
  • phi - the east-positive longitude of the point at which to calculate the stress [rad].
  • t - the time in seconds elapsed since pericenter, at which to perform the stress calculation [s].
Returns: float
the τ_φθ component of the 2x2 membrane stress tensor.
Overrides: StressDef.Tpt