HY-1C satellite project adopts the a.m. and p.m. satellites network which increases
observation times and improves global coverage. Ultraviolet Image (UVI) and
Satellite Calibration Spectrum (SCS) was loaded on HY-1C which would improve
the atmospheric correction accuracy of nearshore turbid water and the
quantifying observation ability of ocean color. The coverage width of Coastal
Zone Imager (CZI) was widened and the spatial resolution was fined to meet the
needs of application. Automatic Identification System (AIS) was added to obtain
position and property information of ships. Enlarged ocean satellite
ground-base application system to improve processing and servicing ability also
the reliability. HY-1C project could better meet the needs of the monitoring
of ocean color, sea surface temperature, coastal zone, ocean disaster and
environment, at the same time, it can provide service to natural resource
investigation, environment and ecology, emergency reaction and disaster mitigation,
meteorology, agriculture, 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 period: 1 day for one satellite and 0.5 day for two satellites.
b. CZI period: 3 days for one satellite.
c. UVI period: 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: 1:30AM±30 minute;
The payloads onboard on HY-1C are COCTS, CZI, UVI, SCS and AIS, the objective of each sensors is shown as bellow:
1) COCTS
COCTS mainly used for the detection of ocean color parameters (chlorophyll
concentration, suspended sediment concentration, dissolved organic matter, etc.)
and sea surface temperature filed. By continuously obtain long-term China’s
offshore and global ocean color and temperature data, to study and get the
distribution of ocean primary productivity, the situation of marine fisheries
and aquaculture resource, providing scientific basis for the development and
utilization of marine biological resources; providing ocean color and
temperature data for the study of global change, the role of ocean in global
CO2 circulation and the detection of El-Nino.
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 (CZI) is mainly used for getting real-time imagery of ocean-land
interaction zone to monitoring costal area; getting to know the suspended
sediment distribution of key estuary and harbor; CZI also provides real-time
monitoring of ice, red tide, green tide, pollutant and other ocean
environmental disaster.
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
UVI mainly used to improve COCTS’s atmospheric correction accuracy of nearshore turbid water.
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
SCS
providing on-board synchronous calibration for 8 visible bands of COCTS and 2 ultraviolet
bands of UVI, monitoring the on-board radiance stability of COCTS’s visible
bands and UVI. Visible and NIR bands is capable of the continuously spectrum
data download with a speed of 5nm/s within 400-900nm; capable of in-orbit solar
calibration, for both 2 ultraviolet bands and 8 visible 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
AIS mainly used to obtaining the position and property information of ships over the sea, providing data service for rights defensing, marine disaster prevention and mitigation, marine fishery production, etc.
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.
