ISPI quick reference guide
General information
The Infrared Side Port Imager ISPI (eye-spy)
is a facility imager at the CTIO Blanco 4-m telescope,
serving a broad range of science programs through the following capabilities:
- 1-2.4 micron imaging with 2K x 2K HgCdTe HAWAII-2 array
- 0.3 arcsec/pixel sampling matched to f/8 IR image quality of ~0.6 arcsec
- 10.25 x 10.25 arcmin field of view,
- broad band J,H and Ks, as well as a set of narrow band filters.
A list of available filters can be found on the ISPI filter page.
Performance
During the January 2003 engineering night weather permitted us to
measure the throughput of ISPI at the telescope, see table. The ISPI
throughput is very similar to the throughput of Flamingos at the Kitt
Peak 4m.
Exposure times and signal-to-noise ratios can be estimated using the
exposure time calculator on the
CTIO Infrared Instrument web page .
ISPI performance
based on data taken on Jan. 19, 2003
Band
|
Background Flux
(electrons/sec)
per pixel |
Integrated Flux
(electrons/sec)
for m=15 star |
point source detection limit
5 sigma in
60 sec |
| J |
310 |
4000 |
19.6 |
| H |
1560 |
5000 |
18.9 |
| K' |
2160 |
3300 |
18.3 |
The HAWAII-2 array in ISPI
The array, as set-up in ISPI since May 2003,
has the following performance characteristics:
- Gain: 4.25 e-/ADU
- Well depth: 150,000 e-
- Linearity: 1% full frame linear range is ~13,000 ADU's
- Minimum exposure time: 3.227s
NOTE:
For data taken prior to May 2003 please consult
the ISPI support staff.
Observing with ISPI
ISPI is run through a
Graphical User Interface,
in which all array control parameters, such as exposure time, number of
co-adds, as well as filter, telescope focus and telescope off-set can be set.
The GUI can also initiate a series of observations, to conduct for
example a dither sequence, a focus sequence, or a sequence of darks.
These sequences are simple ASCII text files, which can be prepared in
advance. Examples of such observing sequences can be found
here .
February 13, 2007