Arroyo::Hufnagel_Valley_model Class Reference

#include <Hufnagel_Valley_model.h>

Inheritance diagram for Arroyo::Hufnagel_Valley_model:

List of all members.

Public Member Functions
	Hufnagel_Valley_model (const Hufnagel_Valley_model &hv_model)
	Hufnagel_Valley_model (const char *filename)
	Hufnagel_Valley_model (const iofits &iof)
	Hufnagel_Valley_model (const three_frame &ground_ref_frame, const std::vector< double > &layer_heights, double pseudowind, double A=1.7e-14)
	~Hufnagel_Valley_model ()
Hufnagel_Valley_model &	operator= (const Hufnagel_Valley_model &hv_model)
void	read (const char *filename)
void	read (const iofits &iof)
void	write (const char *filename) const
void	write (iofits &iof) const
void	print (ostream &os, const char *prefix="") const

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Detailed Description

A class to implement a multilayer approximation to the analytic atmospheric model proposed by Hufnagel and Valley. Paraphrasing Sasiela p. 60, the analytic model is

	.00594 (W/27)^{2} (1e-5*h)^{10}exp(-h/1000) +
Cn^{2}(h) =	2.7e-16 exp(-h/1500) +
	A exp(-h/100)

where W is the pseudowind and A is a parameter that is usually set equal to 1.7e-14. The HV-21 model has this value for A, and W is equal to 21. This model is sometimes referred to as the HV 5/7 model. (Note - h is apparently in meters)

Sasiela tabulates the turbulence moments for 4 different values of the pseudowind W. They are reproduced in the table below.

	HV 21	HV 35	HV 54	HV 72
r_0 (cm)	4.96	4.67	4.18	3.70
theta_0 (urad)	6.90	3.95	2.40	1.71

where r_0 and theta_0 are quoted at .5 microns.

To generate a multilayer approximation to this model, the user must supply a vector of layer heights to the constructor. The convention for assigning turbulence weights to the layers is as follows. The C_{n}^{2} profile is integrated from the ground to the midpoint between the first and second layer, and this weight is assigned to the first layer. The profile is integrated from this point to the midpoint between the second and third layers, and this weight is assigned to the second layer. For the highest layer, the profile is integrated from the midpoint between the second highest layer and the highest layer to infinity.

Note that this procedure does not necessarily preserve theta_0 in the table above, but does preserve r_0.

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Constructor & Destructor Documentation

Arroyo::Hufnagel_Valley_model::Hufnagel_Valley_model (  const Hufnagel_Valley_model &  hv_model  )

Copy constructor

Arroyo::Hufnagel_Valley_model::Hufnagel_Valley_model (  const char *  filename  )

Construct from a file

Arroyo::Hufnagel_Valley_model::Hufnagel_Valley_model (  const iofits &  iof  )

Construct from an iofits object

Arroyo::Hufnagel_Valley_model::Hufnagel_Valley_model (  const three_frame &  ground_ref_frame, const std::vector< double > &  layer_heights, double  pseudowind, double  A = 1.7e-14 )

Construct from a three frame.

Arroyo::Hufnagel_Valley_model::~Hufnagel_Valley_model (   )  [inline]

Destructor

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Member Function Documentation

Hufnagel_Valley_model& Arroyo::Hufnagel_Valley_model::operator= (  const Hufnagel_Valley_model &  hv_model  )

Operator =

void Arroyo::Hufnagel_Valley_model::print (  ostream &  os, const char *  prefix = "" )  const [virtual]

Print Reimplemented from Arroyo::refractive_atmospheric_model.

void Arroyo::Hufnagel_Valley_model::read (  const iofits &  iof  )

Read from iofits Reimplemented from Arroyo::refractive_atmospheric_model.

void Arroyo::Hufnagel_Valley_model::read (  const char *  filename  )

Read from file Reimplemented from Arroyo::refractive_atmospheric_model.

void Arroyo::Hufnagel_Valley_model::write (  iofits &  iof  )  const

Write to iofits Reimplemented from Arroyo::refractive_atmospheric_model.

void Arroyo::Hufnagel_Valley_model::write (  const char *  filename  )  const

Write to file Reimplemented from Arroyo::refractive_atmospheric_model.

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The documentation for this class was generated from the following file:

• Hufnagel_Valley_model.h

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