Exposure Time Calculator for Space Telescope

This form will calculate the count rates and S/N ratio for a simulated spectrum of ONE source.

Question and Instruction

Imaging Exposure Time Calculator


1. Instrument parameter:

Select one Filter:

Pixel Size: arcsec

System Efficiency: %

Readout Noise e-

Dark current e-/s

Telescope Aperture: m

upload user-defined throughput curve file:

2. Calculation Mode

Exposure time (total time) needed to obtain a S/N ratio of
S/N ratio reached in an exposure time (one time) of sec
Limit magnitude with time (one time) sec with S/N ratio
With times exposure

3. Source

Choose Source Type:
Point source with fwhm arcsec

Use a circular region containing of total source light.
Use a Circular region for getting the maximum Photometric SNR
Use a square region of size:

Extended Source
Type:

Sersic profile with sersic index(shape parameter) n = with Radius including 80% energy a = arcsec
Gaussian profile with full width half maximum of arcsec
Uniform diameter is arcsec

Photometric range:

Use a square extraction region of size (pixels):
Use a circular region of diameter (arcsec):

Instrument parameter:

Instrument psf fwhm is arcsec

Normalize the target's flux:
=

4. Choose Source Spectrum Distribution

Non-Stellar Object:
Castelli and Kurucz Models:
Black body with temperature K
a Power-law: Fλ = λ^ (if index=-2, the spectral flux density fv = constant (AB magnitude))
Upload Spectrum File:

5. Background Parameter

a.Standard zodiacal light normalizations:

b.Standard earth shine light normalizations:

6. Extinction Parameter

Extinction Type:
Extinction Map With Rv = Using Galactic System RA(l) = degree and DEC(b) = degree
Specify the extinction E(B-V) =
Extinction applied normalization.
Specify the redshift z =



If you find some bug or have some question, please