EDITOR'S In this issue

40 Pages·2001·2.51 MB·English

by  Winnie Humberson

O b s erving
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March/April 2001 Vol. 13 No. 2
EDITOR’S
In this issue . . .
SCIENCE MEETINGS
Michael King
EOS Senior Project Scientist
Minutes of the Aqua Science Working
Group Meeting . . . . . . . . . . . . . . . . . 3
Representatives from the CloudSat, PICASSO-CENA, PARASOL, Aura and
MODIS Science Team Meeting . . . . . . 11
Aqua science teams are beginning discussions of the afternoon satellite con-
stellation. The intent is to coordinate orbits and resultant data acquisitions for
MODIS Land Team Annual Validation
more comprehensive and consistent monitoring of Earth processes from sat-
Review Meeting . . . . . . . . . . . . . . . . 16
ellites. These discussions build on the morning constellation, which involves
Terra, Landsat 7, EO-1 and SAC-C. These four spacecraft are currently in
Aura Science Team Meeting . . . . . . . . 18
a common orbit plane and altitude, enabling cross-validation of data collec-
tions and multiplying the science returned from each mission. The afternoon
EOS Aura Ground System Review . . . 20
constellation will further complement the inherent benefi ts of formation
fl ying, and may eventually lead to combined data products.
SCIENCE ARTICLES
Following the publication of Volume 2 of the EOS Data Products Handbook
Using Landsat Thematic Mapper Images
last year (describing science data products from ACRIMSAT, Aqua, Jason-1,
to Detect Land Cover Change in South
Landsat 7, Meteor 3M/SAGE III, QuikScat, QuikTOMS, and VCL), Volume
Africa . . . . . . . . . . . . . . . . . . . . . . . 26
1 (describing data products from TRMM, Terra and Data Assimilation) is
being rewritten and updated. Many of the initial data products described
Science Working Group on Data: A Data
in Volume 1 have now been revised due to new data handling capacities,
Distribution Workshop . . . . . . . . . . 29
processing algorithms, and metadata content. In addition, more detailed
information on fi le specifi cations and processing frequency will be included.
The Large Scale Biosphere-Atmosphere
The publication date for Volume 1 of the Data Products Handbook will likely
Experiment in Amazonia (LBA): new
be later this year.
research results start to form building
blocks for integration . . . . . . . . . . . 31
Technical brochures describing the ICESat and Aqua missions are being
produced by the EOS Project Science Offi ce, and are complemented by sepa-
ANNOUNCEMENTS
rate brochures produced for AIRS, AMSR-E and CERES. In addition, a new
MODIS brochure describing the instrument on both Terra and Aqua is being
EOS Scientists In The News . . . . . . . . 36
produced. These brochures are intended to inform science professionals
and other colleagues of the scientifi c objectives and capabilities of the mis-
Earth Science Education Program
sions and instruments. These and many other EOS mission and instrument
Update . . . . . . . . . . . . . . . . . . . . . . 37
publications are available from the EOS Project Science Offi ce Web site at
eos.nasa.gov.
What is ECHO? . . . . . . . . . . . . . . . . . 38
Finally, I’m happy to report two new additions to the EOS Project Science
Science Calendar . . . . . . . . . . . . . . . . 39
Offi ce staff. Chris Shuman has joined Goddard Space Flight Center and
The Earth Observer Information/Inquiries
. . . . . . . . . . . . . . . . . . . . . . . Back cover
(Continued on page 2)
THE EARTH OBSERVER
will serve as the ICESat Deputy Project Scientist. Shuman
received his Ph.D. in Geosciences from the Pennsylvania
State University, and was previously a visiting research
fellow with the Universities Space Research Association at
Goddard, and an Assistant Research Scientist at the Uni-
versity of Maryland, College Park. Douglas Rabin has also
been named the SORCE Deputy Project Scientist. Rabin is
the Head of the Solar Physics Branch at Goddard, and will
be a positive connection to the The Solar and Heliospheric
Observatory mission, Living With a Star, and other solar
missions.
May 3, 2001
Seal Pups trapped in the White Sea
According to the Russian Polar Research Institute for Fisheries
and Oceanography, between 250,000 and 300,000 Greenland seal
pups face death by starvation over the next two months due to a
cruel trick by mother nature. The seals, most of them less than two
months old, are trapped on ice sheets that remain locked in the
White Sea, located near Archangel in Northern Russia. Typically,
during the spring thaw the ice sheets break up and fl ow with the
currents northward into the Barents Sea, the seals’ spring feeding
grounds. The seal pups hitch a ride on the ice fl oes, living on
food caught by their mothers until they arrive in the Barents Sea.
Unfortunately, their mothers departed for the Barents Sea weeks
ago leaving the pups with only their own individual stores of fat
to sustain them.
In a normal year, the seal pups’ trip from the White Sea out to
the Barents takes about six weeks, and the seals have adapted to
rely upon this mechanism of mother nature. During their yearly
migration, the mother seals usually stay with their pups and
feed them until their pelts turn from white to grey—a sign that
the pups are mature enough to swim and feed themselves. Unfor-
tunately, this year unusually strong northerly winds created a
bottleneck of ice near the mouth of the White Sea, thus blocking
the fl ow of ice and trapping the pups.
These images of the White Sea were acquired by the Moder-
ate-resolution Imaging Spectroradiometer (MODIS), fl ying aboard
NASA’s Terra spacecraft. The top image, taken May 3, 2001,
shows the large ice shelf still trapped in the White Sea. The
bottom image was taken by MODIS almost this same time last
year (April 23, 2000). Notice there was much less ice in the White
April 23, 2000
Sea this time last year as most of it was enroute to the Barents Sea.
(Images courtesy Jacques Descloitres, MODIS Land Rapid Response Team.)
2
March/April 2001 (cid:127) Vol. 13 No. 2
GPS. The latest word is that the Flight
Planning Board meets on February
Minutes of the Aqua Science 8 and will likely slip Jason/TIMED
to August. Meanwhile, a commercial
Working Group Meeting Boeing launch called Earthwatch is
sliding into the October slot. ICESat
has a December slot and Iridium has
moved to March 2002. If Aqua does
— Steve Graham ([email protected]), Aqua Outreach Coordinator
not launch in September/October 2001,
— Claire Parkinson ([email protected]), Aqua Project Scientist
then it will likely be early 2002.
Parkinson thanked Sabelhaus and indi-
cated that the Aqua mission is fortunate
in having someone of Sabelhaus’s expe-
rience and caliber available for taking
over the Project Manager’s job. She then
mentioned that Volume 2 of the EOS
Data Products Handbook is now
The Aqua Science Working Group met
available and copies can be obtained
at the Goddard Space Flight Center
Sabelhaus from [email protected] or by
(GSFC) on February 8, 2001, chaired by
then gave an phoning Lee McGrier at (301)
Claire Parkinson, the Aqua Project Sci-
update on the status of 867-2037 or Steve Graham at (301)
entist. Parkinson opened the meeting
the Aqua launch, noting that 867-2036. In addition, the AMSR-E logo
at 8:30 a.m. with a welcome and the
there are three units on the and brochure have been printed and are
announcement that George Morrow, the
spacecraft that are currently causing being distributed.
Aqua Project Manager, will be leaving
concerns: the Formatter Multiplexer
the Aqua project on February 9 and
Unit/Solid State Recorder (FMU/SSR), Following Parkinson’s comments,
will be replaced by Phil Sabelhaus. Par-
the transponder, and the transponder Ramesh Kakar, the Aqua Program Sci-
kinson elaborated on the critical work
interface electronics (TIE). The Aqua TIE entist at NASA Headquarters, spoke
performed by Project Managers and
will be removed from the spacecraft about the recompetition of the Terra and
thanked Morrow for all he has done
and sent back to B. F. Goodrich for Aqua science teams. The present science
to ensure that the mission will reach
inspection, because a similar Aura TIE team contracts run out on December 21,
the objectives laid out by the scientists.
has recently failed vibration testing. 2001, and Procurement may or may not
Morrow then explained that he has
The system Comprehensive Perfor- allow contract extensions beyond that
greatly enjoyed working on the Aqua
mance Test (CPT), scheduled to start date. A new NASA Research Announce-
mission but has decided to take a job
February 8, was delayed to allow time ment (NRA) for recompeting the team
with Jackson and Tull, a private aero-
to complete the procedure dry runs; the efforts is under development, with Jim
space company, as Vice President for
current estimated start date is February Dodge and Jack Kaye (both of NASA
their Aerospace division. He thanked
14. [Editors note: The Dry Run System CPT Headquarters) working on it. It is
everyone for working with him and
was successfully completed on March 6. No expected that the new NRA will recog-
noted that he will be present at Vanden-
new signifi cant hardware issues were identi- nize three broad categories: algorithm
berg Air Force Base with many others to
fi ed.] Additional problems include paint maintenance, science data analysis, and
watch the launch of Aqua.
cracking on the Earth shade on AIRS forward compatibility. Kakar noted that
and excess oil in the CERES deployment the sum of funding in the three cat-
Morrow then introduced Phil Sabelhaus
mechanisms. The latter problem is being egories would approximate the avail-
as the incoming Aqua Project Manager.
addressed by placing the deployment able funding in the science team funding
Sabelhaus offered a brief history of his
mechanisms in a thermal chamber at an line.
involvement with NASA Earth Science
elevated temperature in order to bake
missions, including Project Manager of
out the excess oil. It is not clear at this time if separate
TOMS/EP, TOMS on ADEOS, GOES,
NRAs will be needed for the two plat-
Landsat, Aura, and VCL. He is happy
Sabelhaus noted that the Delta Launch forms or if one will suffi ce. It is possible
to have the opportunity to be involved
Manifest is fi lling up and is crowded that an NRA for Terra will be released
with the Aqua mission, especially at this
in the June/July timeframe with Jason/ this summer and the new NRA for Aqua
critical and exciting stage, and is com-
TIMED, MAP, Genesis, Geolite, and (concentrating on AIRS/AMSU-A/HSB
mitted to the mission’s success.
3
THE EARTH OBSERVER
and AMSR-E) could appear approxi- CERES Team MODIS Team
mately one year after launch. Rather
than going into more detail, Kakar Barkstrom then relayed his experience Parkinson then introduced Vince Salo-
deferred to Jack Kaye, who was at the with fi rst light images from Terra and monson, the MODIS Science Team
afternoon session to expand upon these offered thoughts on possible fi rst light Leader, to present initial results from the
issues. images from Aqua. Barkstrom noted Terra MODIS and thoughts on possible
that it is not premature to start now fi rst light images from Aqua. Salomon-
Next, Kakar offered an introduction preparing for the fi rst Aqua press con- son noted that MODIS is performing
to the NASA Earth Science Enterprise ference. The audience to keep in mind well in terms of spatial, spectral, radio-
Research Strategy (2000-2010), noting when preparing images is the general metric, geometric, and quantization per-
that it should be a guiding strategy for public. Word charts and bar charts formance. All major systems are work-
the next decade and that it is based on should be avoided, and the images ing, the focal planes and bands are
the following fi ve questions: should be kept simple. well registered and are performing
(overall) better than specifi cations, and
The Aqua Working Group, or its spokes-
• How is the global Earth system calibration looks good. Also, noise and
person, needs to decide on the main
changing? other factors have been identifi ed and
Aqua story to present during the press
reduced, leading to a useful state for
conference. At the Terra press confer-
• What are the primary forcings of the scientifi c use. Finally, studies are con-
ence, the main story centered on atmo-
Earth system? tinuing to further optimize Level 1B
spheric aerosols. It would be helpful to
data. Salomonson also noted that there
have movies and animations detailing
• How does the Earth system respond are 5 MODIS direct readout stations in
the concepts, as opposed to still images.
to natural and human-induced the U.S., and 25 stations or more are
changes? Barkstrom noted that moderately expected to be in place worldwide soon.
acceptable formats are global images
• What are the consequences of with recognizable features (geography) Regarding Level 1B improvement areas,
changes in the Earth system for that are visually interesting. He posed the following Terra MODIS characteris-
human civilization? the question of whether or not the U.S. tics have been fi xed or improved on the
should be in the center of the visuals. Aqua MODIS:
• How well can we predict future
Also, Barkstrom praised the MISR team
changes in the Earth system? as having done the best preparations for • radiance versus scan-angle response
the Terra press conference. Their work for the thermal emissive bands;
Under these primary questions, there
is a good model to follow for the Aqua
are 23 additional questions focusing on press conference, with video sequences • optical cross-talk from band 31 (11
specifi c research areas. Kakar pointed and well-rehearsed responses. µm) into bands 32 (12.0 µm) through
out that 6 of the 23 questions concern 36 (14.3 µm);
the global water cycle. Lastly, Kakar The Public Affairs Offi ces at NASA
reviewed the current missions and Headquarters and GSFC will have the • electronic cross-talk amongst bands
launch schedule. primary responsibility for orchestrating 5-7 and bands 20-26; and
the press conference. It is anticipated
“First Light Images” and Science
that we will use the services of the GSFC • non-uniform digital count bin-fi ll
Team Presentations
Scientifi c Visualization Studio and Earth factors, particularly for bands 31-36.
Observatory team and should begin two
Next, Parkinson explained the impor- to three months prior to the fi rst press Salomonson showed a chart summariz-
tance for NASA public relations of conference rehearsal in order to perfect ing the operational characteristics of the
getting good “fi rst images” to show the image formats and color scales. Terra MODIS since “fi rst light” in Febru-
publicly a few months after launch Based on the Terra experience, it will ary 2000. Several problems have been
and mentioned that Bruce Barkstrom probably require about three iterations stabilized starting in the fall of 2000. The
and Vince Salomonson, the CERES before the images are suitable. Also, the MODIS Characterization Support Team
and MODIS Team Leaders, respectively, teams should expect to do a complete is now looking at making quantifi ed
have been through this process in 2000 rehearsal at an IWG prior to the press estimates of the overall uncertainty in
with the Terra spacecraft. conference. the Level 1 product. Preliminary esti-
mates show that the uncertainty is being
reduced with time and has reached
planned levels for Bands 4 and 5. In
4
March/April 2001 (cid:127) Vol. 13 No. 2
the thermal infrared bands (particularly data by the GSFC DAAC are approx- Salomonson commented on the near-
the sea surface temperature bands at 11 imately 1%. The DAAC is processing term challenges facing the science team,
and 12 µm) the performance has not Terra at 2X on Silicon Graphics Origin including work to improve the Level
reached adequate levels but is improv- 2000s, and is expected to reach 3X with 1B products, to optimize the use of the
ing as more efforts continue to reduce the addition of the remaining Aqua products by the scientifi c community,
the various uncertainty factors. hardware and installation of the S4P and to maximize the publication and
on the Origins to support reprocessing. oral presentation of recent results. The
Commenting on the overall status of the MODAPS is shipping 300 GB per day to team is working to fi nd and implement
science products, Salomonson said that the DAACs, and 167 TB of MODIS prod- effi ciencies in the processing, reprocess-
~40 products are currently in develop- ucts have been archived at the GSFC, ing, archiving, and distribution of the
ment. Most of the products have been EROS Data Center, and National Snow data.
released in Beta format for examination and Ice Data Center DAACs.
by the scientifi c community, starting in Lastly, Salomonson commented on fi rst
the fall of 2000. Work continues on all A MODIS User Survey was conducted light images from Aqua. The present
the products to get them to the point at the Fall 2000 AGU meeting. The understanding is that fi rst light for
where they can be considered routinely goal of the survey was to address MODIS will occur 39 days after launch,
useful for scientifi c or applications whether or not MODIS data distribution versus 68 days after the launch of
studies. It is suggested that anyone is lower than it should be. Roughly 350 Terra. In the Terra MODIS case, needed
wishing to employ the MODIS products people from fi elds ranging from edu- outgassing/purging did not occur suf-
should communicate with the appropri- cation (K-12 and college introductory fi ciently, and actions were necessary to
ate MODIS Science Team member to remote sensing courses) to atmospheric eliminate icing on the radiative cooler in
ascertain the utility of the product or, at and oceanographic research participated August 2000. The current perception is
least, should pay careful attention to the in the survey. The reasons for not order- that the Aqua MODIS schedule is too
quality “fl ags” on the products. Addi- ing MODIS data can be grouped into fast, and MODIS fi rst light should prob-
tionally, the MODIS Web pages contain four categories: ably occur closer to 50 days after launch.
much useful material on quality assur- However, the MODIS Science Team is
ance and validation efforts for the prod- 1. Data Maturity - Several people indi- ready to work with the Project to
ucts. In general, use by the scientifi c cated that they would wait for more better understand the plans and trade-
community is encouraged so as to mature data products because of offs. Salomonson mentioned the impor-
obtain feedback and hasten validation. resource limitations. (This is typical tance of using common words rather
for new data products.) than scientifi c terms at the “fi rst light”
MODIS-associated data processing sys- press conference and of having a central
tems (i.e., the GSFC DAAC and the 2. Data Access - Several people had theme.
MODIS Adaptive Processing System experienced diffi culties with order-
[MODAPS]) reached stable global pro- ing data and have not tried again. AIRS/AMSU-A/HSB Team
duction in fall 2000 and are consistently (Information needs to be distributed
ingesting, processing, archiving, and regarding the improvements in data After a short break, George Aumann,
distributing data. The data systems access.) the AIRS Project Scientist, offered a
are resource-constrained and effi ciencies status update on the AIRS/AMSU-
in hardware, systems, software, algo- 3. Data Subsetting (spatial, temporal A/HSB program. The AIRS/AMSU-A/
rithms, and even products are being and parameter) - The transfer of HSB instruments have been integrated
evaluated. While hopeful for additional large data fi les is diffi cult. Several on the Aqua satellite at TRW for
resources, all avenues are being pursued users would fi nd the data more the last six months, and many of
for producing consistent, timely data manageable if vertical profi les of the comprehensive performance tests
sets. A goal is to produce a consistent, selected parameters for specifi ed (all with spectrometer and detectors at
one-year data set starting sometime in geographical regions were available. ambient temperature) have been com-
2001. This effort may begin in June 2001, (Subsetting/data mining efforts are pleted. AMSU-A and HSB time code
using the best performing algorithms taking place.) issues in the packets are currently being
available at that time. It will cover the resolved. The pre-thermal vacuum scan
period from November 2000 to Novem- 4. Data Formats - Some users mirror inspection is scheduled for Feb-
ber 2001. expressed concern about the data ruary 18. The thermal vacuum test itself
only being available in HDF-EOS will allow testing of AIRS detectors at
Regarding production status, EDOS is format. (Use of data format transla- the in-orbit temperature of 60 K.
working well and reorders of Level 0 tors is being considered.)
5
THE EARTH OBSERVER
Regarding software status, AIRS Prod- 1B, cloud-free data. The AIRS science shows a rainfall decrease during the
uct Generation Software (PGS) version team will assist with cloud-free iden- warm phase, perhaps due to changes in
2.1 has been delivered to the GSFC tifi cation, cloud-cleared radiance utili- drop size distribution.
DAAC, and version 2.1.5 (the last pre- zation, and the forward and tangent
launch PGS delivery) will have the model. The next workshop is scheduled Regarding AMSR-E fi rst light images,
fi nal interfaces frozen, plus additional for May 2001. Lobl noted that AMSR-E has a strong
Quality Assurance indicators. Level 1B heritage and thus the only new mea-
software has been revised based on Some initial thoughts on possible fi rst surements to be highlighted are the
data from the Lockheed Martin thermal light images from AIRS/AMSU-A/HSB highest spatial resolution passive-micro-
vacuum chamber and has been docu- presented by Aumann include: wave data yet in the extratropics (the
mented in the Level 1B Algorithm Theo- TRMM Microwave Imager has similar
retical Basis Document version 2.2i. • animation of a global map going resolution in the tropics) and the highest
from the top of the atmosphere to 6 GHz resolution yet (50 km vs. SMMR’s
Global simulated software has been the surface to illustrate global tem- 120 km). Possible fi rst light images
used for software development, incor- perature soundings; include extratropical imagery of rain
porating real instrument noise and spec- systems over the land and ocean, sea
tral characteristics. The global data fi eld • animation of global maps of several ice, soil moisture, snow cover, oceanic
has been based on National Centers days of total water from AMSU to wind fi elds near deep low pressure
for Environmental Prediction (NCEP) illustrate water transport; and systems, global imagery of sea surface
Aviation forecasts including multi-layer temperature (even through clouds), and
clouds, liquid water, surface emissivity, • animation of several days of global improved spatial sampling of rainfall.
and surface temperature. A “golden images from an upper tropospheric
day” exercise was completed over the sounding channel to illustrate After Lobl, Yasuyuki Ito, the ADEOS-II
period January 22-25, 2001. This exercise “water wind.” Science Project Manager at the Earth
involved testing the data fl ow, display, Observation Research Center (EORC)
retrieval and analysis software. The A special section in the Journal of Geo- of the National Space Development
team is currently analyzing the data. physical Research with fi rst results from Agency of Japan (NASDA), presented a
AIRS/AMSU-A/HSB is being planned, status update on ADEOS-II and AMSR-
Regarding validation activities, the AIRS with refereed papers from each AIRS E/Aqua, plus thoughts on possible fi rst
team is working towards the original Science Team member. The papers light images. Ito began with a brief over-
schedule of DAAC delivery of validated would be submitted at Launch + 12 view of the Earth observation satellite
PGS by Launch + 12 months. Validation months, but will be in print no sooner programs of Japan, including a break-
support teams will be integrated into the than 10-12 months after submission. down of the organization of the Offi ce of
plan as soon as the teams are offi cially Earth Observation Systems.
selected. AMSR-E Teams
Next, Ito provided a status update on
Aumann reiterated the challenge set Following Aumann, Elena Lobl pre- the ADEOS-II program. The ADEOS-II
forth by James Baker of NOAA and Dan sented on behalf of Roy Spencer, the system Proto-Flight Test was completed
Goldin of NASA to demonstrate AIRS U.S. AMSR-E Science Team Leader. Lobl in December 2000, and the satellite will
data assimilation impact by Launch + noted that the AMSR-E Science Inves- be stored by the end of March 2001.
12 months. To that effect, a workshop tigator-led Processing System (SIPS) Functional tests and additional tests on
was held on December 6, 2000, and was should be ready for the Mission Opera- the satellite’s sensors will be conducted,
attended by representatives of NCEP, tions Science Systems-2 test. Lobl then with a Post Qualifi cation Review to be
the European Centre for Medium-Range described a passive-microwave rainfall held by the end of March 2001, aiming
Weather Forecasts, the UK Met. Offi ce, mystery, wherein various estimates of towards a February 2002 launch target.
the Canadian Meteorological Center, tropical ocean rainfall change during
and the GSFC Data Assimilation Offi ce El Niño Southern Oscillation (ENSO) The AMSR-E fl ight instrument is under-
(DAO). The operational data link via (+10% during the warm phase) are at going a systems test aboard the Aqua
NOAA’s National Environmental Satel- least double those inferred from surface spacecraft at TRW, while the Level 1
lite Data and Information Service is in energy and atmospheric radiation bal- data processing system is undergoing
place and is currently producing daily ance considerations. Possible explana- its fi rst mission simulation test. The
AIRS/AMSU-A/HSB “data” using the tions for these differences include rain- second mission simulation test will be
NCEP Aviation forecast model. The cur- fall effi ciency and changes in drop size conducted from April to July 2001. Also,
rent data assimilation uses only Level distribution. The TRMM radar actually the Level 2 and 3 data processing system
6
March/April 2001 (cid:127) Vol. 13 No. 2
is in the manufacturing and test phase. Level 3 images on water vapor, sea sur- to MODIS-Land (see http://
face temperature, and other variables, modarch.gsfc.nasa.gov/MODIS/),
Regarding data distribution for and, if feasible, animations using Level there will be a strong emphasis
ADEOS-II and AMSR-E, the Earth 1B and/or Level 2 data. on piggyback validation activities
Observation Center (EOC) will be the with AERONET and FLUXNET.
receiving, archiving, processing, and Discussion MODIS-Ocean will conduct an
distributing center while the EORC will AVHRR pathfi nder/MODIS com-
serve as the algorithm development and Following Ito’s presentation, Parkinson parison, conduct cruises with a
calibration/validation center. Validated led a brief general discussion on Aqua marine interferometer, and utilize
Level 1 and Level 2 data will be avail- fi rst light images, including possibilities the MODIS Ocean Buoy. MODIS-
able at the EOC 12 months after launch, for highlighting, such as improved Atmosphere will utilize land valida-
but PI’s will have access to the non-val- resolution, morning/afternoon tion sites and fi eld campaigns such
idated data before their public release. contrasts, and the full hydrological as ARM, AERONET, FIRE-ACE, and
NASDA and NASA will implement cat- cycle. Barkstrom noted that we need SAFARI.
alog, browse, and order interoperability to move beyond highlighting high-res-
for the ADEOS-II phase. olution images and show how these • Bruce Wielicki reported on the
data can affect people’s lives. He also CERES Team’s calibration and vali-
Ito noted that geophysical products mentioned that it would be helpful to dation efforts for the Terra CERES
from the Global Imager (GLI) on stress the combination of instruments and the TRMM CERES. Most CERES
ADEOS-II will include aerosol param- and their technical differences. Bruce validation makes use of long-term
eters, cloud parameters, chlorophyll-a, Wielicki of the CERES Team added that validation sites such as ARM, BSRN,
colored dissolved organic matter, sus- the images should focus on a common and AERONET sites for clouds,
pended solid weight, sea surface tem- theme, such as the water cycle. Aumann aerosols, and surface radiative
perature, vegetation index, and snow mentioned that television weather fore- fl uxes. Current CERES fi eld plans
grain size and impurities. Additionally, casters are now claiming a 5-day accu- include the CERES ARM Validation
the SeaWinds sensor will measure sea racy and that there is a large public Experiment (CAVE), the Chesapeake
surface wind vectors, while the Polar- awareness of this, leading to the sugges- Lighthouse and Aircraft Measure-
ization and Directionality of the Earth’s tion that maybe we should highlight the ments for Satellites (CLAMS), sched-
Refl ectances (POLDER) will measure impact that Aqua will have on weather uled for July 12 - August 1, 2001, and
clouds and aerosol parameters, and the forecasting. It was also noted that many the CERES Ocean Validation Experi-
Improved Limb Atmospheric Spectrom- of the topics could be the same as those ment (COVE). The CERES fi eld val-
eter II (ILAS-II) will measure ozone and in the upcoming Aqua Science Writers’ idation plans are detailed on the
HNO. The geophysical products from Guide. CERES Web site at http://www-
3
AMSR on ADEOS-II and AMSR-E on cave.larc.nasa.gov/cave/.
Aqua include cloud water, water vapor, Validation
precipitation, sea surface wind speed, • Eric Fetzer explained that on-orbit
sea surface temperature, sea ice, snow Following the general discussion, Peter validations for the AIRS Team will
depth, and soil moisture. Hildebrand, the Aqua Deputy Project focus strongly on operational rawin-
Scientist for Validation, presented a sondes and dedicated radiosondes
There was an AMSR PI meeting in summary of the Aqua Validation Work- at times of overpass, plus observa-
Kyoto, Japan from October 30 to ing Group meeting held at GSFC on Feb- tions of the marine surface state
November 1, 2000 and a joint U.S./ ruary 7, 2001. In attendance at the Feb- from buoys. Soundings will come
Japan AMSR/AMSR-E, team meeting ruary 7 meeting were approximately 20 from ARM-CART validation sites,
held in conjunction with an Inter- participants from the MODIS, CERES, Brazil, and Australia. Fetzer noted
national Geoscience and Remote Sens- AIRS, and AMSR science teams. At the that the full validation plan is on
ing Symposium in Honolulu in July meeting, validation plans for each Aqua the AIRS Web site, http://www-
2000. Currently, an AMSR/AMSR-E PI instrument were reported on by instru- airs.jpl.nasa.gov/.
meeting is tentatively planned for the ment team representatives. In summary:
November 2001 to January 2002 time • Elena Lobl noted the AMSR-E Web
frame. • Vince Salomonson reported the site at http://wwwghcc.msfc.
MODIS Team’s scheduled com- nasa.gov/AMSR/. AMSR-E ocean
Ito suggested, as possible fi rst light parisons with other satellites, product validation will utilize buoy,
images from AMSR-E, a selection of ground measurements and science radiosonde, and satellite observa-
high-resolution Level 1B images and campaigns, and models. Specifi c tions. Sea ice product validation will
7
THE EARTH OBSERVER
use ship and aircraft campaigns, as siderable interest in the formation-fl ying initial orbit phasing relative to the morn-
well as MODIS and Landsat obser- concept at NASA Headquarters and that ing constellation must be considered
vations. Rainfall products will be his term for the afternoon satellite for- to avoid ground station confl icts with
validated through several fi eld cam- mation is the “A-Train”, with Aqua those spacecraft. Aqua will need to time
paigns using a ground X-band radar at the lead and Aura at the tail. He the ascent maneuvers so that after it
and data from the Eureka and the showed an impressive animation of the reaches its fi nal orbit position, it will not
Kwajelein radars, plus comparisons A-Train in orbit and mentioned several fl y over the polar ground stations at the
with the TRMM Precipitation Radar important complementarities amongst same time as other spacecraft. The pre-
and the TRMM Microwave Imager. the instruments on the fi ve A-Train sat- liminary Aqua ascent plan to 705 km
Snow products will be validated on ellites. consists of four maneuvers to be com-
25-km grid, regional, and river basin pleted by day 14. The synodic period
scales using aircraft observations. Schoeberl then introduced Rich Macin- between spacecraft at 695 km and 705
Soil product validation will utilize tosh and asked him to review formation km is 32 days; this is the maximum time
many land surface hydrology experi- fl ying requirements and the Aqua we would have to wait for proper initial
ments around the globe, modeling requirements for initial orbit phasing. phasing before starting ascent maneu-
and data assimilation, and compari- Formation fl ying of Aqua with Aura vers.
sons with AIRS and MODIS. requires that both spacecraft must main-
tain a ground track on the World Refer- If Aqua is required to phase with the
Hildebrand noted that common themes ence System (WRS) using frequent burns morning constellation, the time needed
surrounding Aqua validation plans (once every three months) to counteract to perform the ascent to mission altitude
include the upcoming announcement atmospheric drag. A ground track con- could increase signifi cantly depending
concerning the pending Aqua validation trol of ±20 km results in minor varia- on the initial phasing at launch. The
proposals and the expected recompe- tions in spacecraft separation of ±43 sec- best-case scenario has an initial phasing
tition of the science team efforts. The onds along-track. The largest effect on at launch that allows the fi nal desired
next steps for the Aqua Validation the spacecraft separation over time is position to be achieved with no changes
Working Group will be to evaluate from the difference in ascending node to the nominal maneuver plan. The
the common validation needs and to mean local time (MLT) between the worst-case scenario has an initial phas-
develop common calibration/validation two orbit planes. While both spacecraft ing at launch that requires a delay of
venues. The next meeting will take maintain their ground tracks, separation one synodic period before starting the
place on August 1, 2001, the day before will change gradually as the MLT ascent. In the latter case, 32 days would
the next Aqua Science Working Group changes. be added to the 9-day maneuver period,
meeting. for a total of 41 days. However, from
Both spacecraft must perform occasional the Terra experience, this would not nec-
During the validation discussion, inclination maneuvers to control MLT essarily preclude instrument operation
Wielicki pointed out the need to sort drift so minimum desired separation (on during the ascent period.
out the defi nitions of beta versus provi- the order of 15 minutes) is not violated.
sional versus validated data products. The Aqua MLT is allowed to range from Wayne Esaias, the MODIS-Ocean Group
Salomonson agreed, adding that it is 1:30 p.m. to 1:45 p.m., while the Aura leader, offered the suggestion that in
probably an issue most appropriately MLT is allowed to range from 1:30 addition to formation fl ying of the
addressed by the EOS Investigators’ p.m. to 2:00 p.m. Aqua and Aura A-Train we should look into the pos-
Working Group. must agree on desired MLT ranges sibility of having the daytime path of
to maintain separation; this implies an the Aqua MODIS match the previous or
Formation Flying of the EOS agreement on the frequency of incli- next nighttime path of the Terra MODIS.
Afternoon Satellites nation maneuvers. Smaller MLT range
implies smaller, more frequent inclina- The next speaker, Bruce Wielicki from
After the lunch break, the meeting tion burns—1 or 2 per year versus 1 or 2 the CERES Team, continued with the
reconvened at 1:30 p.m. with Parkinson over the lifetime of the mission. formation-fl ying theme by elaborating
introducing the next set of three talks, on the synergisms of the train. Wielicki
all centered on the issue of formation Macintosh noted that, during the ascent reiterated that the A-Train consists of
fl ying of the afternoon satellites Aqua, phase, Aqua will perform maneuvers to Aqua, PICASSO, CloudSat, PARASOL,
PICASSO, CloudSat, PARASOL, and synchronize with the WRS, and could and Aura, with Aqua leading the train.
Aura. The fi rst speaker in the group, normally synchronize with any WRS The nominal plan for the others is to
Mark Schoeberl, the Aura Project Scien- path since it is the fi rst spacecraft in precess across the Aqua-MODIS scan-
tist, began by noting that there is con- the afternoon constellation. However, ning path.
8
March/April 2001 (cid:127) Vol. 13 No. 2
Wielicki explained that together, researchers will be able to obtain appro- enhances the science of both missions.
PICASSO, CloudSat, and Aqua will priate subsets of Level 1 data from the
allow studies of cloud feedbacks in the other missions. Stephens then presented some examples
climate system in ways never before of CloudSat synergy with MODIS,
possible. These studies would involve Stephens elaborated on how information CERES, and AMSR. He noted that
processes in atmospheric state, cloud from one sensor can enhance the prod- MODIS optical depth provides indepen-
physics, cloud optics, and top of atmo- ucts derived from others, with the pos- dent information that more tightly con-
sphere, surface, and atmospheric radia- sibility of development of new products strains the relation between the power
tive heating profi les. Additionally, for- and an opening of the possibilities for returned from radar and the water and
mation fl ying will be useful for cloud addressing new science. ice content of the radar volume, thus
validation with CloudSat and PICASSO. improving retrievals.
Variables include cloud amount, cloud Stephens then spoke briefl y on the
top height, cloud physical thickness, CloudSat mission, noting that it will Finally, Stephens stressed the impor-
cloud base, cloud visible optical depth, include the fi rst 94 GHz spaceborne tance of coordinating CloudSat and
cloud infrared spectral emissivity, cloud radar system. A unique feature is that Aqua validation efforts, noting also that
liquid water path, cloud ice water path, the radar is extremely sensitive and has the need exists to establish a data fl ow
cloud particle phase, and cloud particle a wide dynamic range. It sees the major- dialog and subsequent plan of action
size. ity of clouds, from thin cirrus clouds among members of the constellation
to deep convective clouds producing instrument teams.
The A-Train will also facilitate aerosol heavy precipitation. The CloudSat sci-
validation. The vertical locations of aero- ence objectives are to: Recompetition
sol layers are critical for source region
back-trajectories, and the locations of • measure the vertical structure of Following Stephens, Jack Kaye from
cloud/aerosol in the same vertical layers clouds and quantify their ice and NASA Headquarters spoke on the plans
are critical for indirect aerosol forcing. water content, in development for dealing with the
MODIS can obtain good aerosol data upcoming expiration of science team
over dark surfaces, but the A-Train will • predict clouds and precipitation, contracts. This will involve a separation
allow us to obtain such data also over of the science efforts into two main cat-
snow, ice, and all other surfaces. The • improve weather prediction and egories. First, the Core Instrument Team
optimal scenario is to combine PICASSO clarify climatic processes, Activities, including algorithm mainte-
with MODIS and PARASOL. Wielicki nance and key aspects of data product
noted that precession across the MODIS • improve cloud information from validation, will be covered under an
swath would help verify causes/physics other satellite systems (particularly appropriate, somewhat restricted solici-
of angle dependent aerosol cloud prop- Aqua), tation. This will maintain the continuity
erties from passive imagers providing and heritage to insure high quality data
global climate data. • investigate the effects of aerosols on products for release to the broad science
clouds and precipitation, and community. It is expected that support
Next, Graeme Stephens of Colorado for these activities will decrease over
State University presented on CloudSat • investigate the utility of the 94 GHz time as the processing algorithms sta-
and the afternoon constellation. He reit- radar for observing precipitation in bilize and the initial validation studies
erated that the combination of constella- the context of cloud properties from prove successful. Both Terra and Aqua
tion observations well exceeds the sum space. instrument team activities will likely be
of the individual parts and explained covered in one solicitation.
that part of his purpose in speaking at Stephens then commented on two for-
this meeting is to convince Aqua sci- mation-fl ying scenarios. The original Second, an NRA will be released to
entists of the importance of CloudSat scenario involved CloudSat in formation solicit from the Earth sciences commu-
contributions. The CloudSat team has with PICASSO-CENA (and more loosely nity long-term, multi-platform, multi-
developed optimized retrieval methods with Aqua) to provide essentially instrument Science Data Analysis inves-
that combine heterogeneous (multi-sen- instantaneous lidar/radar views of the tigations. Investigations will be sought
sor) information derived from the con- atmosphere. The current scenario that address questions relating to dis-
stellation. This, however, requires avail- involves CloudSat fl ying in a tight for- cipline areas and key science themes
ability of the data. A critical issue thus mation with Aqua, aligning CloudSat rather than addressing single instru-
becomes the exchange of data and how radar with nadir pixels of MODIS. The ment data sets. It is expected that
quickly and at what cost the CloudSat combination of Aqua and CloudSat data support for these investigations will
9
THE EARTH OBSERVER
increase over time as the data products ing of the EOS production environment. • TDRSS is assumed to be available as
from the EOS platforms reach appropri- scheduled. The Project has requested
ate stages of maturity. Researchers will Barkstrom noted that the instrument nearly continuous coverage for the
be allowed to use alternative algorithms teams have made considerable improve- fi rst three hours after launch and
from those used in the standard prod- ments and effi ciencies to codes and algo- two 20-minute TDRSS contacts per
ucts, although the funding here will not rithms. However, increased hardware orbit thereafter.
be for new algorithm development. capacity is needed above the 1996 base-
line to generate the higher-order geo- • Timeline is based on the nominal
With these two types of solicitations, physical data products already commit- plan and does not account for con-
the goal is to fund activities that carry ted for Terra and planned Aqua science. tingencies.
the EOS project through transitions from Provisional cost estimates suggest that a
pre-launch initial algorithm develop- much-desired three-fold increase in pro- • Scheduling of the MODIS roll
ment, to post-launch algorithm refi ne- duction capacity at the DAACs and SIPS maneuver does not yet account for
ment and stability, to initial validation could be obtained with a cost of approx- moon phase.
studies, and fi nally to broader validation imately 7% of the annual ESDIS budget.
studies and uses of the data products to • Instrument scheduling is based on
Aqua Integrated Mission Timeline
address and answer important scientifi c results of the last IMT review
questions. The intention is to shift fund- as well as continuing information
After Barkstrom, Fran Wasiak of the
ing dollars more and more from algo- exchange with Instrument Opera-
Aqua Instrument Planning Group pre-
rithm development and maintenance to tions Teams and TRW, the Aqua
sented an update on the Aqua Inte-
scientifi c analysis. spacecraft developer.
grated Mission Timeline (IMT). The
third IMT review was held on October
Data Processing Issues surrounding instrument com-
17, 2000, and was attended by repre-
manding during the fi rst two weeks
sentatives from the Aqua project, TRW,
Following Kaye, Bruce Barkstrom, rep- include the fact that spacecraft and
Instrument Operations Teams, and the
resenting Chris Justice and the Science AMSR-E RunUp activities occupy most
Flight Operations Team (FOT). The cur-
Working Group on Data (SWGD), pre- of the fi rst two weeks. Teams still
rent version of the IMT is based on
sented on Terra and Aqua data process- have the option to schedule benign
all the IMT reviews (March, July, and
ing issues, beginning with an overview activities with their instruments during
October 2000). Some adjustments in the
of a workshop held on June 1-2, 2000, this period if they choose to do so, and
Aqua maneuver plan are to move the
at GSFC. The June 2000 workshop was MODIS may choose to perform transi-
MODIS yaw maneuver from days 26-27
called to evaluate how well the EOS tion to the ON state earlier than day
and 30-31 to days 32-33 and 37-38 and
Data and Information System (EOSDIS) 15 now that AMSR-E RunUp has been
add a CERES yaw maneuver on day 41.
supports current and upcoming EOS shortened.
One important maneuver that has not
missions, to determine how require-
changed is the deep-space pitch maneu-
ments have changed, and to recommend It is the AIRS Team’s preference not
ver scheduled for day 55. Plans call to
solutions to meet evolving needs. to perform deep-space constant pitch
baseline the IMT in March or April 2001.
maneuvers, and the current IMT
The participants at the June 2000 work- assumes no pitch maneuvers for the
Assumptions guiding the IMT team
shop discussed the then current oper- scheduling of AIRS activities, despite
include:
ating status of EOSDIS, in particular the planned pitch maneuver on day 55.
the lower than expected throughput and • Activities, in general, are scheduled Under some scenarios, AIRS would not
how it should be addressed. They noted to occur during the FOT prime shift. complete its activation checkout until
that the February 1996 baseline sizing after the Launch-plus-90-days threshold.
used to implement EOSDIS is not ade- • Per FOT direction, only one EOS Hence, AIRS has provided a preliminary
quate to support current science data Polar Ground Network pass is used alternate plan of activities that needs to
needs. Because that baseline was estab- per orbit. be implemented into the Baseline.
lished before the algorithms were
developed and could be run in the pro- • Instruments use only Alaska and The slip in the MODIS yaw maneuvers
duction environment, it did not have a Svalbard ground stations. Spacecraft is primarily because the MODIS Team
clear empirical basis. Terra instrument bus uses Alaska, Svalbard, and Wal- has elected to wait until day 15 to begin
team representatives presented revised lops. McMurdo is not available for the outgassing procedure and prefers 14
system sizing estimates based on current use. days of outgassing rather than the ear-
experience and improved understand- lier scheduled 11 days. MODIS activities
10