|
The following table summarizes the magnitude depth we expect to reach
on each pointing of the three survey components. Please keep
in mind that the images can be taken within a fairly large range
of airmass and sky brightness values for some filters and this
explains why some of the these numbers differ slightly from
DIET (MegaCam exposure time calculator). Average values between various conditions
were taken to build up these numbers. For information on
exact depth based on the actual data, please refer to the
individual survey web sites.
The dithering scale defines how much of the gaps in the
CCD mosaic can be eventually covered in the final stacked image.
The Wide survey uses exclusively a very large pattern (cf the
MegaPrime/MegaCam pages) while the Deep survey has been using a small
dithering pattern during the first year for efficiency reasons but only
in the g', r', i' and z' filters (u* uses the large pattern as in the Wide).
Starting 04AQ03 (April 2004), the Deep survey is using exclusively the
large dithering pattern.
The Very Wide survey has such short exposures that it's not
reasonable in terms of observing efficiency to slice down the total
integration time to do some dithering.
The field of view of the camera is 1 square degree.
| |
| Survey |
Area (deg x deg) |
Filters |
Depth for a point source
SNR=5, 1.15"ap.,0.8" |
Total integration
per field |
Observing strategy |
| Deep Synoptic: ~3 nights per run & 5 runs a year for each of the four fields |
| |
4 |
u* |
28.7 |
33 hr (10%) |
11 x 660 sec per run |
| |
|
g' |
28.9 |
33 hr (10%) |
4.25 x 5 x 225 sec per run |
| |
|
r' |
28.5 |
66 hr (20%) |
5.25 x 5 x 360 sec per run |
| |
|
i' |
28.4 |
132 hr (40%) |
5.25 x 7 x 520 sec per run |
| |
|
z' |
27.0 |
66 hr (20%) |
5.25 x 5 x 360 sec per run |
| |
| Survey |
Area (deg x deg) |
Filters |
Depth for a point source
SNR=5, 1.15"ap., 0.8" |
Total integration
per field |
Observing strategy |
| Wide Synoptic - Large dithering filling the larger gaps in the mosaic. |
| |
170 |
u* |
26.4 |
6000 s (27.2%) |
7x850 s |
| |
|
g' |
26.6 |
2500 s (11.3%) |
5x500 s |
| |
|
r' |
25.9 |
2000 s (9.1%) |
Twice 2x500 s 3 years apart |
| |
|
i' |
25.5 |
4300 s (19.5%) |
7x620 s |
| |
|
z' |
24.8 |
7200 s (32.7%) |
9x800 s |
| |
| Survey |
Area (deg x deg) |
Filters |
Depth for a point source
SNR=5, 1.15"ap., 0.8" |
Total integration
per field |
Observing strategy |
| Very Wide - No dithering (single pointing per field) |
| Ecliptic strip |
410 |
r' |
25.0 (560 s) |
4x140 s (33%) |
Optimized for KBO detection |
| +/- 2 deg over 325 deg |
|
g' |
25.5 (600 s) |
2x[3x70+90] s (35%) |
with 2 epochs in g' 3 yrs apart |
| |
|
i' |
24.4 (540 s) |
3x180 s (32%) |
Partial internal KBO follow-up. |
| |
| 