Geoscience Reference
In-Depth Information
2.2.
Main parameters of the Schmidt telescope
(i) Diameter of the correcting lens: 1.0 m.
(ii) Diameter of the primary mirror: 1.2 m.
(iii) Focal ratio:
F
=
f/D
=1
.
8
f
=1
.
8m).
(iv) Effective field: 3
.
14
◦
(linear diameter: 100 mm).
(v) Limiting magnitude of the telescope: 20.7.
(vi) Center wavelength of the correcting lens: 656.3 nm.
(vii) Light power distribution: 80% of light in less than 2
(linear diameter
is less than 20
µ
m).
(viii) Distortion caused by optical designing and machining: less than
15
µ
m.
(ix) Bearing of the tube: bending to focal plane less than 0.02 mm.
(x) Tracking precision: 1
/
4min.
(xi) Pointing precision: less than 10
.
2.3.
Site of the observational station
The NEO search telescope is mounted at Xuyu station. The site is from the
north to Nanjing in 120 km. Its position is at N 32
◦
44
.
2
0
.
5
, E 118
◦
27
.
9
±
0
.
5
and sea level is 180.9 m. The survey covering sky is the northern area
from latitude S 20
◦
. By historical record, the observing nights from 1995 to
1999 were averagely 214.6 per year and 207.5 per year from 1990 to 1999.
We did observation from August 1999 to July 2000 for the whole year, got
the astronomical observing nights being 194. In the year, the number of
astronomical observing hours was, 1652.
Seeing Observation Results: from June to December in 1999, we got
total 1493 seeing, the average result is
θ
=0
.
81
.
Figure 3 shows that seeing changes symmetry to midnight.
±
3. “Auto-Navigation for NEO Exploration” Proposal
In addition to ground-base NEO survey and investigation, we have tabled
a proposal “auto-navigation for NEO exploration” and hope to have inter-
national cooperation.
The aims of asteroids exploration are to study asteroids and their origin,
by which we can learn the origin and evolution of the solar system and look
for near-Earth Asteroids, investigate their spatial distributions and trace
the Potentially Hazardous Objects (PHO).
