Atmosphere temperature profile sounder, ATPS-II
Wang Mochan, Zhang ZhaoXiam
Shanghai Institute of Technical Physics,
Academia, Shangai, China
Abstract
There are twenty optical channels to detect vertical profile of Earth atmosphere's temperature in Atmosphere Temperature Profile Sounder (ATPS-II) and there is great breakthrough in infrared detector, narrow photo-filter, radioactive cooler and scanning step mirror control. Properties of optical mechanical and electronic system satisfied the requirement of design. Because of the great improvement of optical mechanism design ATPS-II has extensional abilities in long wave, short wave and visible channels. It extends the sound property of F-Y metrological satellites.
Introduction
The Atmosphere Temperature Profile Sounder (ATPS-II) in meteorological satellite has twenty optical channels to detect vertical profile of earth's atmosphere. It can provide the temperature, moisture and other meteorological factors of atmosphere profile timely and continuously, Especially in deserts, polar areas and oceans, which occupy 75% of Earth's surface. There is great significance for meteorological forecast of digital and middle long range.
| Properties of ATPS_II are given in the blow: |
Satellite Orbit
Satellite Orbit declination
Optical field of view (FOV)
Cross-track scan (CTS)
Number of step
Ground area of CTS
Ground Instantaneous field of view (IFOV)
Step time
Scan time
NEDN See Table 1
Calibration Stable Blackbody
Cooling space
Calibration period
Number of LW channels
LW detector
Number of SW channels
SW detector
Word length
Bit rate
Optical aperture
Weight about
Power
Size |
900km
98 degree
1.25 degree
+()- 49.5 degree
56
2240km
19.6km(nadir)
100ms
6.4s
See Table 1
290k
265k
3k
256s
12(See Table)
HgCdTe(6.7-15mm)
7 (See Table 1)
InSb (3.7-4.6um)
13 bit
2880 bits/s
150 mm
about 40kg
35w (average)
700*320320 mm3 |
Optical and Mechanical System
- Optical System
Optical system is composed of scanning step mirror, D.K system relay and light cone hyperbolical concentrator (LCHC). LW, SW and visible channels in PTPS-II are used only one stop of view. So the identity of twenty optical channels IFOV is satisfied. From experiments, full IFOV of LW, SW and visible spectrum are equalized. It can give chances to extend the vision channel.
LW photo-filters (120 and SW photo-filter (7) are installed in filter wheel which rotates in a period of 100 ms. Information of 19 channels are sequencely detected by IR detector. Due to the small dispersion. Fov's uniformity and small FOV lose. The LCHC is used.
| Major optical parments of ATPS-II are: |
Optical apeature
Fnumber of main optices system
System stop of main optices
Full FOV
Effective F number of system
Stop of FOV
Focus of area Longwave
Shortwave
Vision
|
150mm (diameter)
1.6
0.21*0.15mm
1.30 degree (LW)
0.6417(LW)
0.6732 (SW)
0.9167 (Vision)
5.40mm (diameter)
1.92 mm (diameter)
1.98 mm (diameter)
2.50mm (diameter) |
- Mechanical System
Mechanical system is composed of calibrative blackbody's, main optics relay mechanism, scanning step mirror system, filter wheel, chopper, electronic box and base plate. The rotative components such as chopper and filter wheel require precise tempreture control for ATPS-II this was based on radiative energy exchange between two rotate components and uniform temperature shield (UTS.) the inner side of filter wheel and chopper are spread on black-paint in order to enhance energy exchange to UTS. The chopper and filter wheel are heatless connected with rotate axes. The accuracy of temperature will be less than 0.05k. Magnetic positional detectors are installed among the scanning step mirror, chopper and filter wheel for synchromotion control.
