Camera

Top  Previous  Next

LL_Camera

View Inside Camera:

LL_Camera_Inside

 

Camera models a camera with 2D focal-plane-array sensor chip. An incident wavefront is propagated to the focal (sensor) plane using an FFT, and the resulting intensity computed. If multiple wavefronts are received simultaneously they are assumed to be mutually incoherent, so their intensities add. The net intensity is then integrated over the exposure length to produce an "integratedIntensity" output in units of J/m^2. Camera also allows an optional delay used to model readout time: if this is set non-zero, then the output only becomes available at that delay after the end of the exposure length window.

See the LightLike User Guide for a detailed discussion of the triggering of sensor exposures. Note in particular that the input "sampleInterval" is only used to generate multiple samples within one "exposureLength". To obtain one sample per "exposureLength" (the typical practice), set "sampleInterval" to 0.0.

For guidance in setting the sensor-plane mesh parameters, see the LightLike User Guide.

Like all LightLike optical sensors, Camera works with both pulsed and continuous wave illumination.

Note that two of the parameters are annotated as "Used ONLY with Wavesharing". For essentially all LightLike usage, these parameters have NO effect whatsoever: leave the values at their defaults (for advanced usage, see LightLike User Guide for details).

C++ type

name

value

description

Parameters

double

focalLength

1.0

focal length (m)

double

minWavelength

1.0e-06

minimum wavelength sensed (m)

double

maxWavelength

1.0e-06

maximum wavelength sensed (m)

int

nxyPupil

512

Used ONLY with Wavesharing (see LightLike User Guide)

double

dxyPupil

0.01

Used ONLY with Wavesharing (see LightLike User Guide)

int

nxyDetector

512

dimension of sensor plane mesh (same in x & y) in cam focal plane

double

dxyDetector

1.0e-06

mesh spacing (m) of sensor plane (same in x & y)

double

computationalLag

0

time lag between end of exposure and availability of outputs (s)

Inputs

Light

incident

Light()

Describes all the incident light

bool

on

true

on/off switch (on=true, off=false)

double

exposureInterval

0.001

Time between start of successive exposure windows (s)

double

exposureLength

0.000002

Length of each exposure window (s)

double

sampleInterval

0.0

Time between samples within one exposureLength (s)

Outputs

Grid<double>

fpaImage


Temporally-integrated intensity at focal plane (J/m^2)