1995 Research Activity Report of Japanese POLDER Team

Yoshiyuki Kawata
Japanese POLDER Sensor Team Leader
Kanazawa Institute of Technology

We can summarize our team's research activities in 1995 as follows:

  1. Several atmospheric aerosol observations were made over Japan and the Pacific Ocean using sunphotometers and photopolarimeters. Some preliminary analyses of these measurement data were done.
  2. Cross-calibration experiments between such instruments for observing the atmosphere were also conducted at the Meteorological Research Institute, Japan.
  3. Reflectance characteristics for several land targets were studied by using CNES's airborne POLDER data obtained in the La Crau campaign.
  4. The retrieval algorithms of size distribution of aerosols, as well as their refractive index, were examined by using CNES's airborne POLDER data in the Medimar campaign.

The 2nd International POLDER Science Working Team meeting will be held in Toulouse, France on March 27 - 29, 1996.

E-mail from Dr. Ann Lifermann, Project Scientist for POLDER, CNES concerning the tentative agenda and objectives of 2nd IPSWT meeting is as follows:

The general objective of this second IPSWT meeting is to draw a precise picture of the scientific activities related to POLDER both from the Project and the Science team prospectives.

The first day with be entirely devoted to information from the Project, more specifically about the Ground Segment with most of the session dealing with POLDER Products: what they will be, how and when you will get them.

The next days will focus on the POLDER Science Plan.

The second day will be dedicated to the first phase of POLDER validation plan (also called core validation plan).

The current plans for level 2/3 POLDER processing chains validation by the science team developing the algorithms will be presented. Questions or comments are expected either through discussions after each presentation or written questions to be examined at the end of the meeting.

The third day will deal with the longer term scientific activities. Three areas of research are more specifically identified: POLDER phase II validation plan, POLDER future Class 2 algorithms development and scientific studies with POLDER data.

We call for PIs presentation(s) of their contribution(s), by category, according to their involvement regarding the four above-mentioned topics:

For that purpose, AN ABSTRACT FOR EACH TOPIC should be submitted BEFORE MARCH 1ST. We ask speakers for a focused presentation of their work addressing specifically the category of their talk. The presentation time will be revised according to the answers.

A form is attached in order to harmonize the presentation. Please use it for your abstract(s) submission; if your proposal is relevant to several topics, fill out one separate form for each category of presentation and return the abstracts via E-mail attachments (or Fax) to me.

Apart from these presentations, additional information may be brought by researchers to the IPSWT by means of posters. In such a case, indicate the room needed for your poster.

We expect that the plenary sessions will allow a survey and a better understanding of the POLDER validation activities.

I hope that this organization will be agreeable to you and look forward to including your contributions in the agenda.

Yours Sincerely,

Provisional AGENDA 2nd International POLDER Science Working Team meeting

*** Wednesday MARCH 27, 1996

9:00 Registration
9:30 Welcome

Part 1: POLDER organization
Instrument, Ground Segment, Operation

Part 2: POLDER Class 1 Products

  1. POLDER Products description
  2. Level 1 processing, calibration and quality assessment
  3. Scientific processing development and expertise
  4. Data production and delivery
  5. Data policy, license for use
  6. Services to PIs

*** Thursday MARCH 28, 1996

Part 3: POLDER validation plan - Core validation plan Review

    Including PIs' measurement opportunities: ( over US, Canada, Australia, Japan.. )
    >>>>> call for presentations (10 to 20 min. each + 5 min. questions)
    Including Marine in situ measurement opportunities
    >>>>> call for presentations (10 to 20 min. each + 5 min. questions)
    Including Land in-situ measurement opportunities
    >>>>> call for presentations (10 to 20 min. each + 5 min. questions)
    Including measurement opportunities
    >>>>> call for presentations (10 to 20 min. each + 5 min. questions)
  7. OCTS/AVNIR data for POLDER validation

*** Friday MARCH 29, 1996

Part 4. Longer term scientific activities

  1. PIs contribution to phase II validation Plan
    >>>>> call for presentations (10 min. each + 5 min. questions)
  2. PIs contributions toward class 2 algorithm development
    >>>>> call for presentations (10 min. each + 5 min. questions)
  3. PIs contributions to scientific studies with POLDER data
    >>>>> call for presentations (10 min. each + 5 min. questions)

Answers to written questions about core validation plan
Synthesis by theme
Any other business

Total Ozone Mapping Spectrometer

Katsuhisa Suzuki
Japanese TOMS Sensor Team Leader
Yokohama National University

As of 1995, Nimbus 7, the Total Ozone Mapping Spectrometer (TOMS), and Meteor 3 TOMS instruments have measured global total ozone and volcanic sulfur dioxide for 16 years. ADEOS-TOMS will continue these measurements to the end of this century. The primary experimental objectives of the TOMS on the ADEOS mission are to:

The TOMS instrument measures near and middle solar ultraviolet radiation backscattered by the Earth's atmosphere at wavelengths of 308.6, 312.5, 317.5, 322.3, 331.2, and 360.0nm.

ADEOS-TOMS operations, data processing and data distribution are conducted by the Science Operation Center (SOC) at Goddard Space Flight Center. The SOC processes all near-real-time data obtained at US receiving stations and JAXA's EOC. The preliminary Level 3' data set is available to science or operational users via Internet.

The calibration and validation plans for ADEOS-TOMS are implemented by JAXA's EORC. At Watukosek, Indonesia, Brewerspectrometer and ozone- sonde observations started from November 1994. Ozone vertical profiles have been obtained continuously every two weeks since then. These observations are important for validating the ozone data of TOMS in equatorial regions. Ozone-sonde observation at Yakutsk, Russia also started in December 1995.

At Yakutsk, ozone-sonde observation is performed every week. As a result, we have six ozone-sonde stations from latitude 62 N to 8 S in the longitude 130 E zone including four Japan Meteorological Agency stations. This ozone observation chain is important for validating the TOMS data as well as for studying ozone climatology.

NASA Scatterometer

Harunobu Masuko
Japanese NSCAT Sensor Team Leader
Communications Research Laboratory
Ministry of Posts and Telecommunications

Two important meetings were held by the US and Japan NSCAT Science Working Teams (SWT) in 1995. One was the NSCAT Geophysical Validation Sub-Team Meeting held on August 7 during the 21st General Assembly of the International Association for the Physical Sciences of the Ocean (IAPSO) in Honolulu, Hawaii; the other was the ADEOS/NSCAT US-Japan Joint SWT Meeting held in Kyoto from November 29 to December 1. The schedule of the NSCAT operation and the data acquisition, processing and distribution, and the calibration and validation programs in US and Japan for several months after launch were discussed in these two meetings. The present status of the items is reported below.

Schedule of the NSCAT Data Acquisition and Distribution

ADEOS is scheduled to be launched on 17 August 1996. The mission check will then be conducted for the next 25 days. The NSCAT instrument will be turned on after the mission check. The first five days will be spent for instrument checks, including measurement with a resolution of 6 km by 6 km. Optimistically, the wind observation mode (WOM) will start one month after launch, i.e. around September 17. The first two months of the WOM are dedicated to preliminary instrument calibration. The data obtained during this period will be distributed to the project engineers and PIs in "native" format, not HDF. Normal WOM for calibration and validation will start around November 17 and continue for three months on a regular schedule. The data will be distributed in the regular HDF format from then. The instrument calibration, such as antenna pattern measurements, made in White Sands by the JPL project engineers with a resolution of 6 km by 6 km, is scheduled through the two-month instrument calibration and the following three-month WOM. The first Geophysical Validation Workshop will be held five months after launch. The data will be regularly distributed after the Geophysical Validation Workshop, i.e. nearly from March 1997. The final Geophysical Validation Workshop is scheduled at the end of 1997. The final NSCAT SWT Meeting will be held June 5-7, 1996 in Pasadena to confirm the schedule and each validation and calibration program.

NSCAT Simulation Data

The NSCAT simulation data set provided by the JPL project office using realistic wind fields of one week was distributed to the NSCAT PIs by the end of 1995. The simulation data set includes the data of Levels 1.7, 2.0, and 3.0 with the reader software and the documentation written in HDF format on an EXABYTE tape. Users can read the data with the UNIX "tar" command. Other ADEOS PIs who require the NSCAT simulation data set should contact JAXA.

US Calibration and Validation Plans

The US ADEOS/NSCAT Science Working Team is planning (Reference) three categories of postlaunch validation. They are [1] in situ data acquisition, through field campaigns, and subsequent validation analysis; [2] geophysical data validation with no major data acquisition cost, mainly through comparison with data in the public domain, and [3] sensor data analysis. Four groups have been selected for the first category, ten for the second, and five for the third. The four Field Campaigns are (1) Gulf of Mexico Experiment by H. Graber (Univ. Miami), M. Donelan (Canada Centre for Inland Water), and K. Katsaros (Univ. Washington/IFREMER), (2) Moored Instrument Platform in the NW Atlantic Ocean by W. Large and R. Milliff (NCAR), (3) Aircraft Underflight by R. McIntoshu (Univ. Massachusetts), and (4) Construction of Minimet Drifters for NSCAT Verification by P. Niiler and K. Melville (SIO).

The overall scientific goal of the Gulf of Mexico Experiment is to calibrate and validate the NSCAT measurements and to understand the dependencies of radar backscatters on the atmospheric stability and sea state. The experiment is conducted using existing NDBC discus buoys and deploying additional Multispar buoys to make high-resolution measurements of marine surface fluxes and gradients of momentum, heat, and water vapor in the presence of directional sea states. The experiment will be made in October/November 1996.

The objectives of the NW Atlantic Ocean Study are to observe and model the three-dimensional physical and biological response of the upper ocean and main pycnocline to strong wind stress curl, and to provide a unique geophysical verification data set for NSCAT and to quantitatively determine the efficacy of the use of NSCAT winds to improve models of upper ocean response by combining drifter and mooring measurements and model study. The experiment uses a moored instrument platform in the NW Atlantic in conjunction with a drifting buoy experiment proposed by Niiler and Melville (see below).

The Aircraft Underflight Experiment is conducted using the Ku- Band and C-Band radars and a microwave radiometer of the University of Massachusetts Microwave Remote Sensing Laboratory on the NOAA WP- 3D Aircraft for high wind speed conditions during late winter of 1996 or early winter of 1997.

The experiment by the Minimet Drifters for NSCAT Verification is conducted to provide a geophysical wind data set from a two-dimensional ocean surface array, commensurate with the scale of the NSCAT swath. The MINIMET drifters will be air-deployed in a NSCAT verification experiment during high-wind conditions in the Atlantic Ocean northeast of Labrador in November 1996.

Japanese Calibration and Validation Plans

The following calibration and validation activities are planned in Japan: [1] Radiometric Calibration by Underflight with an Airborne Ku- band Scatterometer (Masuko, CRL); [2] Validation using the in situ Measurements by Buoys and Research Vessels (Ebuchi, Tohoku Univ. and Kutsuwada, Tokai Univ.); [3] Estimation and Correction of Atmospheric Effects with OCTS and SSM/I (Arai, Saga Univ.); [4] Cross-Calibration and Cross-Validation with SSM/I, ERS-2/AMI, etc. (Shibata, MRI, Kubota, Tokai Univ., and Ebuchi, Tohoku Univ.); [5] Validation and Model Function Analysis with Numerical Calculation Data (Nomura, JMA and Ebuchi, Tohoku Univ.); and [6] Field Campaign Experiment together with the Ocean Physics and Biology Teams, in addition to monitoring long-term variation of the NSCAT sensor performance.

The radiometric calibration is made by the under-flight experiment using the well-calibrated CRL Airborne Precipitation Radar (CAMPR) operated at 13.8 GHz, almost the same frequency as NSCAT (14.0 GHz). The CAMPR measures the ocean backscatter with full polarizations, i.e. HH, VV, and HV, together with their phase differences, combined with the reliable sea truth measurements by research vessels. A test flight measurement was made on November 23, 1995. The first under-flight experiment is planned in November 1996.

The data is validated using worldwide buoy data including three of the Japan Meteorological Agency's (JMA) operational buoys and a JAXA buoy: JMA Buoy 21002 at the center of the Sea of Japan (37 deg. 55 min. N, 134 deg. 32 min. E), JMA Buoy 21004 south of Japan in the Pacific (29 deg. N, 135 deg. E), and JMA Buoy 22001 in the East China Sea (28 deg.10 min. N, 126 deg.20 min. E). The JMA buoys measure wind speed and direction, SST, air temperature, air pressure, humidity, current speed and direction, wave direction, period of main wave, etc. every three hours with the information of the measurement heights above sea level. The JAXA buoy will be operated at the center of the Sea of Japan near 39 deg. N, 135 deg. E and measures the same items as JMA buoys and 2D-Wave Spectrum every hour.

The Japanese CAL/VAL Team is using the measurements by research vessels (R/V) of Japanese agencies, institutions, and universities. At present, almost 20 R/Vs can provide wind speed and direction data corrected with ship speed and orientation in addition to humidity, SST, air temperature, and pressure with the information of the measurement heights above sea level: six R/Vs of JMA; five of the Fisheries Agency; one of Tokai University; two of Ocean Research Institute; one of Tokyo University of Fisheries; one of Hydrographic Department; Maritime Safety Agency; one of Kagoshima University; one of Nagasaki University; one of Tohoku University; and one of Ryukyu University. The Japanese CAL/VAL Team is still negotiating with other institutions and universities for the use of their R/Vs.

The products of numerical calculation provided for weather forecasting by JMA (GANAL) and ECMWF are also utilized for validating the NSCAT data and for estimating the Geophysical Model Function to derive the wind speeds and directions from the ocean backscatter measurements.

The ADEOS Ocean Biology Team and Ocean Physics Team are planning to make a Joint Field Campaign Experiment around the frontal zone between Oyashio and Kuroshio Currents in the Pacific off the coast of Sanriku in April/May 1997 using several R/Vs.

The results of the calibration and validation work will be archived in the Ground Truth Data Base together with their truth measurements.


W. T. Liu, November 1994: NSCAT Postlaunch Data Validation Preliminary Plan,
NSCAT Project Office, JPL.


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