HaiYang-2D (HY-2D) is
the fourth marine dynamic environment satellite of
China. It integrates active and passive microwave sensors, and is one of the
marine series satellites. HY-2D has high-precision orbit measurement
and orbit determination capabilities, and has the ability to image global image
under all weather conditions during day and night. The major objective of HY-2D is to
monitor and investigate the marine environment, and obtain marine dynamic
environmental parameters including sea surface wind, wave height, sea surface
height, etc. HY-2D could directly provide measured data for early warning of
disastrous sea conditions and provide services for marine disaster prevention and
mitigation, marine rights maintenance, marine resource development, marine
environmental protection, marine scientific research, and national defense
construction.
After
HY-2D launch, it forms three-star network observation with the on-orbit HY-2B
and HY-2C.
1. Observation parameters and
accuracy
Major
observation parameters: sea surface wind, sea surface height, significant wave
height, gravity field, ocean circulation and sea surface temperature, etc.
Other observation parameters:
geoid and water vapor content.
The observation parameters and
application are shown as follows:
Observation parameters
|
Observation parameters |
Application |
|
Major parameters: sea surface wind, sea surface height, significant wave height, gravity
field, ocean circulation Other parameters: Geoid and water
vapor content |
Major application: Sea surface wind, sea state forecast, storm warning, local sea
surface/botton topography, local ocean gravity field, local geoid, ocean
circulation; Other application: marine dynamic process, large-scale weather process,
precipitation forecasting, surface classification, global change. |
Product accuracy
|
Parameters |
Accuracy |
Measurement range |
|
Wind speed |
2m/s or 10% (@ max value) |
2~24m/s |
|
Wind direction |
20° |
0°~360° |
|
Sea surface height |
~5cm |
|
|
Significant wave height |
0.5m or 10% (@ max value) |
0.5~20m |
2. Observation areas
(1) Observation areas:
HY-2D has global continuous observation
capability.
Real-time areas: 5°S~50°N, 100°E~150°E.
(2) Data coverage
Scatterometer (SCA) as the major payload
on the marine dynamic environment satellite has a coverage of not less than 90%
in the global sea area for 1 to 2 days.
Repeat period: 10 days & 400 days
3. Orbit characteristics
HY-2D is regression frozen orbit, and orbit
parameters are as follows:
(1) The main parameters of the early
life ocean observation orbit:
Major semi-axis: 7328.583 km
Inclination: 66°
Repeat
period:10 days
Adjacent track pitch: 292.5185km
Node period: 104.1048 minutes
(2) The main parameters of the end-of-life
geodesic model orbit:
Major semi-axis: 7329.490km
Inclination: 66°
Repeat
period:400 days
Adjacent track pitch: 7.3143km
Node period: 104.1241 minutes
4. Payload
(1) Altimeter (ALT)
a. Objective: ALT with external
calibration mode is objective to monitor sea surface height, significant wave
height and gravity, etc.
b. Technical parameters:
Frequency: 13.58GHz, 5.25GHz
Footprint in limited pulse way: 2km
Ranging measurement accuracy: 2cm (at
nadir)
ALT has the capability of sea and land
monitoring.
c. External calibration mode: output ALT
pulse I/Q raw data. The external calibration process can cover the whole
calibration area.
(2) Scatterometer (SCA)
a. Objective: SCA with external
calibration mode is objective to monitor sea surface wind.
b. Technical parameters:
Frequency: 13.256GHz
Bandwidth (1dB): 1MHz
Polarization Mode: HH, VV
Spatial resolution: 25km
Swath width:
H Polarization: 1350km;
V Polarization: 1700km
Sigma0 measurement accuracy: 0.5dB
Sigma0 measurement range: -40dB~+20dB
(3) Correction Microwave Radiometer
(CMR)
a. Major objective: provide atmospheric
wet tropospheric path delay correction service for ALT.
b. Technical parameters:
Sensor
specification of CMR
|
Frequency (GHz) |
18.7 |
23.8 |
37.0 |
|
Bandwidth(MHz) |
250 |
250 |
500 |
|
Polarization Mode |
Linear Polarization |
||
|
Sensitivity(K) |
0.4 |
0.4 |
0.4 |
|
Calibration accuracy |
1K(@ 120~320K) |
||
|
Dynamic range |
3~300K |
||
|
Linearity |
>0.999 |
||
(4) Automatic Identification System
(AIS)
a. Major objective: Detect, demodulate,
and forward AIS messages.
b. Technical parameters:
Frequency: 161.975MHz,162.025
MHz,156.775 MHz,156.825 MHz;
Swath width: ≥1000km.
(5) Data collection system (DCS)
a. Major objective: receiving buoy
measurement data from China's offshore and other sear areas, and transmitting
the data after storing through the satellite digital transmission channel.
b. Technical parameters:
Frequency: 401.65MHz±55kHz;
