HaiYang-1C (HY-1C)
and HaiYang-1D (HY-1D) constitute Chinese optical satellite constellation for
global ocean monitoring (one in the morning and the other in the afternoon) and
could increase the frequency of observations. The new sensors like Ultraviolet
Image (UVI) and Satellite Calibration Spectrum (SCS) onboard HY-1C satellite will
improve the atmospheric correction accuracy and the ocean color quantitative
observation level of the nearshore turbid water body. The Coastal Zone Imager
(CZI) can provide optical images with a wide swath of 950 km and moderate
spatial resolution (50 m), for the coastal environment and resources monitoring
from space. The Automatic Identification System (AIS) could obtain ship
location and attributes information. HY-1C satellite data could meet the demand
ocean color, temperature, coastal zone and ocean disaster and ocean environmental
monitoring. It also serve natural
resource survey, environmental ecology, emergency disaster reduction,
meteorology, agriculture and water conservancy, etc.
1.
Observation parameters
a. Major observation
parameters: Ocean optical characteristics, chlorophyll concentration,
suspended sediment concentration, dissolved organic matter, sea surface
temperature.
b.
Other observation parameters: sea ice, Green tide, red tide, primary marine
productivity, coastal zone elements, vegetation index, marine atmospheric
aerosols, oceanic ship information.
2.
Observation area
(1)
Observation area:
Real time observation areas: Pacific Northwest
Region that is Bohai, Yellow Sea, East China Sea, South China Sea, Sea of Japan
and coastal zone, etc.
Delayed
time observation areas: Other
global observation areas outside the Pacific Northwest region
(2) Coverage specification:
a. COCTS global coverage: 1 day for one
satellite and 0.5 day for two satellites.
b. CZI global coverage: 3 days for one
satellite.
c. UVI global coverage: 1 day for one satellite.
3.
Spatial resolution and swath width
1)
Spatial resolution at nadir:
a. COCTS: ≤1100m;
b. CZI: ≤50m;
c, UVI: ≤550m;
d. SCS:
UV band: ≤550m;
Visible band:≤1100m;
2)
Swath width:
a. COCTS: ≥2900km;
b. CZI: ≥950km;
c. UVI: ≥2900km;
d. SCS: ≥11km.
4.
Nominal orbital
parameter
1)
Orbit type: Sun-synchronous orbit;
2)
Orbit height: 782km (Nominal value);
3)
Local time at the descending node:
a.
HY-1C: 10:30AM±30 minute;
b.
HY-1D: 1:30PM±30 minute;
The payloads onboard on HY-1C are COCTS,
CZI, UVI, SCS and AIS, the objective of each sensors are shown as bellow:
1) COCTS
The objective of the radiometer is monitoring
global ocean color (chlorophyll concentration, suspended sediment
concentration, dissolved organic matter) and sea surface temperature, etc. Through
continuous acquisition of long-term data on coastal and global sea surface
temperature, the users could study and master the distribution of marine
primary productivity, the status of marine fisheries, aquaculture resources and
environmental quality. The data also could provide scientific basis for the rational development and utilization of marine
biological resources, and provide ocean water color and temperature data for
global change, the role of the ocean in the global CO2 cycle and El-Nino
detection.
Table 1.
Specification of the COCTS instrument
|
No. |
Band (μm) |
Measuring condition[1] |
SNR |
Max radiance[2] |
Observation objective |
|
1
|
0.402~0.422 |
9.10 |
349 |
13.94 |
Yellow substance, water pollution |
|
2
|
0.433~0.453 |
8.41 |
472 |
14.49 |
Absorption of chlorophyll |
|
3
|
0.480~0.500 |
6.56 |
467 |
14.59 |
Chlorophyll, sea water optics, sea ice |
|
4
|
0.510~0.530 |
5.46 |
448 |
13.86 |
Shallow sea topography, sediment of low
concentration |
|
5
|
0.555~0.575 |
4.57 |
417 |
13.89 |
Chlorophyll, sediment of low
concentration |
|
6
|
0.660~0.680 |
2.46 |
309 |
11.95 |
Sediment of medium and high
concentration, atmospheric correction, aerosols |
|
7
|
0.730~0.770 |
1.61 |
319 |
9.72/5.0[3] |
Atmospheric correction, s ediment of high concentration |
|
8
|
0.845~0.885 |
1.09 |
327 |
6.93/3.5[3] |
Atmospheric correction |
|
9
|
10.30~11.30 |
NEΔT = 0.2 K (at300 K) |
200-320K[4] |
Sea Surface Temperature, sea ice |
|
|
10
|
11.50~12.50 |
NEΔT = 0.2 K (at300 K) |
200-320K[4] |
Sea Surface Temperature, sea ice |
|
|
[1] Typical
input spectral radiance (mW.cm-2.um-1.Sr-1); [2] Unit:
mW.cm-2.um-1.Sr-1; [3] Dynamic
range can be set to two switches and is adjustable (The default is low switch.); [4]
Brightness temperature measurement range. |
|||||
2) CZI
Coastal zone imager is mainly used to
obtain real-time image data of sea-land interaction area for coastal zone
monitoring, to understand the distribution of suspended sediment in key estuary
harbors, and to conduct real-time marine environmental disasters monitoring and
warning including sea ice, red tide, green tide and pollutants.
Table 2.
Specification of the CZI instrument
|
Band (μm) |
Measuring condition[1] |
SNR |
Max radiance[2] |
Observation objective |
||
|
L: turbid water |
M:35% |
H:80% |
||||
|
0.42~0.50 |
8.41 |
410 |
14.0 |
21.0 |
48.3 |
Chlorophyll, water pollution, sea ice, shallow sea
topography |
|
0.52~0.60 |
4.57 |
300 |
14.0 |
21.0 |
47.0 |
Chlorophyll, sediment of low
concentration, wetland |
|
0.61~0.69 |
2.46 |
248 |
12.0 |
18.0 |
39.0 |
sediment of medium concentration, vegetation,
soil |
|
0.76~0.89 |
1.09 |
240 |
4 |
12 |
25 |
Vegetation, sediment of high
concentration, atmospheric correction |
|
[1] Typical
input spectral radiance (mW.cm-2.um-1.Sr-1); [2] Dynamic
range can be set to three switches and is adjustable (The default is low switch.).
Radiance unit: mW.cm-2.um-1.Sr-1; |
||||||
3) UVI
The objective is to improve the
atmospheric correction accuracy of high turbid water in the nearshore.
Table 3. Specification of the UVI instrument
|
Band (μm)[1] |
Measuring condition[2] |
SNR |
Max radiance[2][3] |
Observation objective |
|
0.345-0.365 |
7.5 |
1000 |
35.6/18.5 |
Atmospheric correction of turbid water,
dissolved organic matter |
|
0.375-0.395 |
6.1 |
1000 |
38.1/16.5 |
Atmospheric correction of turbid water,
dissolved organic matter |
|
[1] The
spectral range corresponds to the spectral range of the 50% transmission of
the normalized system; [2] Typical
input spectral radiance (mW.cm-2.um-1.Sr-1); [3] Dynamic
range can be set to two switches and is adjustable (The default is low
switch.). The data is simultaneously transmitted. |
||||
4) SCS
The objective
is to provide on-board synchronous calibration for 8-band COCTS and 2-band UVI,
to monitor the in-orbit radiation stability for COCTS and UVI. The visible,
near-infrared spectrum of the payload has the ability to transmit 5nm bandwidth
continuous spectral data in the 400~900num range and the in-orbit solar
calibration ability. The bands of the payload include 2 UV and 8 visible,
near-infrared bands of COCTS.
Table 4. Specification of the SCS
instrument
|
No. |
Center wavelength (μm) |
Bandwidth (μm) |
Typical radiance (mW/cm2.μm.Sr) |
SNR |
|
1
|
0.355 |
0.02 |
7.5 |
1000 |
|
2
|
0.385 |
0.02 |
6.1 |
1000 |
|
3
|
0.412 |
0.02 |
9.10 |
800 |
|
4
|
0.443 |
0.02 |
8.41 |
950 |
|
5
|
0.490 |
0.02 |
6.56 |
1000 |
|
6
|
0.520 |
0.02 |
5.46 |
1000 |
|
7
|
0.565 |
0.02 |
4.57 |
950 |
|
8
|
0.670 |
0.02 |
2.46 |
800 |
|
9
|
0.750 |
0.04 |
1.61 |
750 |
|
10
|
0.865 |
0.04 |
1.09 |
950 |
5) AIS
The objective
is to obtain the ocean ship location and the attribution information and to
provide data services for marine right maintenance, marine disaster prevention
and mitigation, and marine fishery production activities.
1) Function: in-orbit collect, store, and
forward AIS messages globally;
2) Signal frequency: simultaneously detect
four frequency points;
a. band1: 161.975MHz;
b. band2: 162.025MHz;
c: band3: 156.775MHz;
d. band4: 156.825MHz;
3) Receiving sensitivity: -112dBm;
4) Swath width: ≥950km.
