8.) Band structure
Table: Definition of the SWS AOT band structure
| sect. |
band |
det. |
ord. |
ap. |
detector |
filter |
area |
wavelength |
resolution |
| |
|
|
|
|
type |
numb. |
type |
|
["x"] |
[µm] |
|
| SW |
1A |
1 |
4 |
1 |
InSb |
1-12 |
Al2O3 |
t |
14-20 |
2.38 - 2.60 |
1870 - 2110 |
|---|
| 1B |
1 |
3 |
1 |
InSb |
1-12 |
Al2O3 |
t |
14-20 |
2.60 - 3.02 |
1470 - 1750 |
| 1D |
1 |
3 |
2 |
InSb |
1-12 |
LiF |
t |
14-20 |
3.02 - 3.52 |
1750 - 2150 |
| 1E |
1 |
2 |
2 |
InSb |
1-12 |
LiF |
t |
14-20 |
3.52 - 4.08 |
1290 - 1540 |
| 2A |
2 |
2 |
2 |
Si:Ga |
13-24 |
LiF |
t |
14-20 |
4.08 - 5.30 |
1540 - 2130 |
| 2B |
2 |
1 |
2 |
Si:Ga |
13-24 |
LiF |
t |
14-20 |
5.30 - 7.00 |
930 - 1250 |
| 2C |
2 |
1 |
3 |
Si:Ga |
13-24 |
SrF2 |
t |
14-20 |
7.00 - 12.0 |
1250 - 2450 |
| LW |
3A |
3 |
2 |
1 |
Si:As |
25-36 |
Al2O3 |
r |
14-27 |
12.0 - 16.5 |
1250 - 1760 |
|---|
| 3C |
3 |
2 |
2 |
Si:As |
25-36 |
LiF |
r |
14-27 |
16.5 - 19.5 |
1760 - 2380 |
| 3D |
3 |
1 |
2 |
Si:As |
25-36 |
LiF |
r |
14-27 |
19.5 - 27.5 |
980 - 1270 |
| 3E |
3 |
1 |
3 |
Si:As |
25-36 |
SrF2 |
r |
20-27 |
27.5 - 29.0 |
1300 |
| 4 |
4 |
1 |
3 |
Ge:Be |
37-48 |
SrF2 |
r |
20-33 |
29.0 - 45.2 |
1020 - 1630 |
| FP |
5A |
5 |
3 |
1 |
Si:Sb |
49(50) |
Al2O3 |
r |
10-39 |
11.4 - 12.2 |
20600 - 24000 |
|---|
| 5B |
5 |
2 |
1 |
Si:Sb |
49(50) |
Al2O3 |
r |
10-39 |
12.2 - 16.0 |
24000 - 32000 |
| 5C |
5 |
2 |
2 |
Si:Sb |
49(50) |
LiF |
r |
10-39 |
16.0 - 19.0 |
32000 - 34500 |
| 5D |
5 |
1 |
2 |
Si:Sb |
49(50) |
LiF |
r |
10-39 |
19.0 - 26.0 |
34500 - 35500 |
| 6 |
6 |
1 |
4 |
Ge:Be |
51(52) |
SrF2 |
r |
17-40 |
26.0 - 44.5 |
29000 - 31000 |
Notes:
SW = short-wavelength section
LW = long-wavelength section
FP = Fabry-Pérot
area = FOV projected onto the sky in ["x"]
t / r = transmission/reflection
SWS06: uses finite (but small) band overlaps (dito for SWS07 SW section)
SWS07: Band 2C ends at 13.16 µm (> 12 µm)
-> SWS
spectral resolution
Comment:
The SWS instrument is divided into three sections (SW, LW, FP section).
The overall band structure (band 1-6) of the SWS is defined by the different
detector arrays, used to observe certain wavelengths. Band 1 and 2, which
cover the wavelength range from 2.38 - 12 µm, are observed with the
SW section (beams transmitting the beamsplitters). Band 3 and 4, which cover
the wavelength range from 12 - 45.2 µm, are observed through the LW
section (beams reflected by the beamsplitters). For the FP filters the LW
grating section is used as wavelength pre-selector. The two FP bands 5 and 6,
which together cover the wavelength range from 11.4 - 44.5 µm, differ
in the scanning FP filter and FP detector used.
The individual (sub-)bands of the SWS are defined by the combination of
detector array, grating order and entrance aperture used for an observation.
None of the 12 grating bands, which alltogether make a full SWS spectrum,
have exactly the same optical path.
Observations in different sections can be made simultaneously ("merged
"), if the different bands use the same entrance aperture.
SWS TUTORIAL /
SWS INSTRUMENT :
Fabry-Pérot <
AOT bands >
merging
Last update: 30-Jul-1998 by D. Kunze ( mail to:
isodata@mpe.mpg.de )