1. INTRODUCTION
The SAC-D/Aquarius satellite was launched in June 10, 2011
from Vanderberg, California. It's a joint mission between
Argentina (through CONAE (National Commission on Space
Activities) and US (NASA). This satellite is a true Observatory
with a suite of sensors for Earth Observation, its weight is 1400
kg, sun-synchronous orbit at 657 km (6 pm ascendant node),
revisit of seven days. Other space agencies have contributed
with instruments and support (facilities and ground segment), as
CNES (National Centre of Space Studies, from France), CSI
(Canadian Space Agency, from Canada), ASI (Italian Space
Agency, from Italy) and AEB (through INPE belonging to
Brazilian Space Agency, from Brazil). The Ground Segment of
CONAE (in Cördoba) has the control of the satellite from the
Ground Station in Cördoba, Argentina.
The primary objective of the mission is to monitor global
variations in ocean surface salinity (SSS) in order to improve
the knowledge about ocean circulation, water cycle and climate.
The SSS is performed with Aquarius instrument (from NASA,
it's an integration of radiometer and scatterometer in L band).
Other oceanic and atmospheric parameters are measured with a
Microwave Radiometer (MWR, from CONAE, in K and Ka
band) as wind speed, rain rate, sea ice, water vapour and liquid
water in clouds. The thermal camera (NIRST) estimates sea
surface temperature and detect high temperature events (fires
and volcanic eruptions). The High Sensitivity Camera (HSC)
generates night images (very useful for fishery activity
monitoring in the sea, studying of electrical storms, polar
auroras and urban application). The DCS (Data Collection
System, from CONAE) can receive meteorological and
environmental data from ground platforms and distribute among
users. The TDP (Technological Demonstration Package, from
CONAE) measures different parameters of satellite position and
velocity.
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
Other two important instruments are ROSA (from Italy) and
CARMEN 1 (from France). The first is an atmospheric sounder,
it allows elaborating atmospheric profiles of temperature,
pressure and humidity, and the second has detectors for studies
of space debris and the effects of radiation on electronic
devices. At the time of this writing, the Aquarius sensor has
collected ocean salinity data since late August 2011, and initial
unvalidated data have been released for evaluation.
The instrument generates a salinity global map every seven days
and is designed to achieve 0.2 psu accuracy over monthly
averages on 150km spatial scale. The data show very robust
signatures of the basin and sub-basin scale salinity patterns.
These measurements can be improved with the use of MWR
data because the rain, the wind and the sea ice are errors source
for the salinity estimation, so the synergy between both
instruments with a coincident footprint allow these
improvements. We are working now on this point providing
MWR data (level L1A y L1B) and generating the first products
(L2). The cal/val of these data is also in progress.
The NIRST camera (bands in: 4, 11 and 12 microns) was
developed in collaboration with Canada, and it is the first time
that microbolometers technology are in the space. Now we are
working on calibration data and preparation of the first
products. The HSC camera, ROSA and CARMEN I
instruments are the second in its type, because the first are on
board the SAC-C satellite (launched in 2000 and currently in
orbit).
The mentioned parameters are being used for the International
Science Team in different issues (emergencies, soil moisture,
health, hydrology, ice, atmosphere, etc.) and they are or will be
available from the web site of NASA and CONAE.
This Mission is in the framework of National Space Plan of
Argentina, which social benefit areas related to this project are:
productive activities as fishery and agricultural, health and
disaster (floods, droughts, fire, volcanic eruptions); ocean and
| OBJECTIVES SPECIFICATIONS RESOLUTION AGENCY
| Understanding ocean circulation, Inte grated L- Band radiometer Three beams:76 x 94, NASA
| globalwater cycle and (1.413 Ghz) and 84x120,96 x 156 km
| climate interaction. Soil moisture scaterometer (1.26 Ghz)
| over Argentina swath: 390 km
Ps Rain rate, winds speed, Bands: 23.8 Ghz V Pol. & Sixteen beams CONAE
sea ice concentration, 36.5 Ghz H and V Pol. < 54 km
Walor vapour, Band widht: 0.5 and 1 Ghz
cloud liquid water
Swath: 380 km
Hot spot events, Bands:4,11y 12um Space resolution: 350 m CONAE
sea surface temperature instantaneous swath 182 Km in temperature: 0.5°C CSA
measurements extended swath 1000 Km smallest burning detectable area
Pointing: +30° 200 m?
Urban lights, electric storms, Pancromatic: 450-610 nm 200-300 meters CONAE
polar regions, Swath: 1600 Km
snow cover
Collection System of meteorological ;
and environmoentaldata 401.55 Mhz uplink 2 contacts per day CONAE
with 200 platforms
Determination of atmospheric profiles
1 on temperature, pressure and GP S Occultation Techniques Horiz: 300 Km Vert: 300m ASI
moisture
Effects of cosmic radiation I: three Si detectors, 1: 256 channels spectra CNES
in electronic devices, Si/Li S: Sensitivity: 0.5 u part.
distributio n of micro-particles S: four MOS sensors at 10K km/sec
and space debris n |)
Position, velocity and time GPS receiver Position: 20m, velocity:1m/sec CONAE
inertial angular velocity Inertial Unit Reference Angular Random Walk:
determination 0.008 deg/sqrth
Table 1: Main characteristics and applications of each instrument on board SAC-D/ AQUARIUS.
Inter
climate
includi:
and at
active
informe
2. GEN
The Ta
instrum
applica
The fol
obtaine
exampl
instrum
the qual
Many :
develop
can be «
Figure.
Figure
