Key milestones

12/2007: Reprocessing of Polder atmospheric products.

A reprocessing of the entire Polder archive was completed to produce all atmospheric products (Aerosols and Clouds) with the latest generation of science algorithms used to process the Parasol data.

12/2007: Transfer of Polder atmospheric product distribution to ICARE.

The ICARE Data and Services Center located at the University of Lille took over the processing, archive, and distribution of Polder atmospheric products, in line with the Parasol mission.

Therefore, from now on, Polder atmospheric products may be downloaded from the ICARE website at: http://www.icare.univ-lille1.fr/

09/2006: BRDF database from Polder 2 is available

A BRDF database from Polder 2 multi-directional measurements is available, and can be downloaded through the POSTEL web site.

11/2005: Reprocessing over Ocean

Polder 1 and Polder 2 data over OCEAN have been reprocessed with several significative improvments:
For aerosols retrieval over ocean, the spatial coverage has been extended by using several means (addition of cases with very few directions and intense aerosol plumes, relaxing of glitter tests...), leading to rather significant changes on monthly syntheses.

Comparison between the two aerosols processing version
Old version

New version

For ocean colour, marine parameters have been slightly modified.

A very good agreement with in-situ measurements has been obtained in both cases, this is presented in the Polder scientific products rubric.

A consistent set of Polder products is now available for a total period of 15 months:
8 for Polder 1 from October 1996 to June 1997
7 for Polder 2 from April to October 2003
The final scientific Polder products can be ordered or downloaded from the Polder website/order desk at: http://polder.cnes.fr

11/2005: Additional products for Land Surfaces

Additional products have been generated by MEDIAS/POSTEL and can be downloaded:

• Polder 1 BRDF database including atmospheric correction
• fapar and albedo parameters

12/2004: Final reprocessing of Polder 2 data

The reprocessing of Polder 2 data was achieved at the end of 2004. This version of the processing accounts for the recommandations of the validation review, held in June 2004. The final scientific Polder 2 products are now available on the Polder website/order desk at: http://polder.cnes.fr

You can directly vizualize or download HDF data files using the "on-line products" menubar. Take a look at the animations of Polder level 3 maps of the main geophysical parameters for aerosols, clouds, ocean color and land. An ordering interface is also available to receive the complete products (first, register in order to get a password)

The second generation of algorithms provides significant improvements with regard to the previous products. We have a lot more insitu data than we had during Polder 1 life and also other major coincident satellite measurement to compare with, particularly MODIS, SeaWifs, MSG, MERIS. All these comparisons show the benefit of using the directional and polarized signatures of the Earth reflectances to complement the spectral signatures.

The Polder 1 dataset will now be re-processed with the new algorithms. Thus a consistant set of Polder products will soon be available for a total period of 15 (8+7) months.

08/2004: Start of Polder 2 data distribution

Polder 2 on ADEOS 2 has been operating under nominal conditions from April 2nd, 2003 to October 24th, 2003, so that around 7 complete months of Polder 2 measurements will be distributed to the international scientific community. Final level 1 archive is now available, as well as a set of preliminary level 2 and 3 products (first scientific results are presented in the "scientific products" rubric).

The present dataset corresponds to the "validation review" products. A final reprocessing is scheduled for October. The Polder 1 dataset will be reprocessed as well.

The "Polder User Services" rubric provides access to the Polder data distribution center. Level 1 data can be ordered by all non-commercial users. Non-validated Level 2 and Level 3 products can only be ordered by Polder 2 Principal Investigators but a preliminary set of main geophysical parameters can be directly vizualized and downloaded on-line in HDF format. Take a look at the animations of Polder level 3 maps of the main geophysical parameters for aerosols, clouds, ocean color and land.

07/2004: Polder 2 Scientific Validation Review

We held our validation review on June 29-30. The second generation of algorithms provides significant improvements with regard to the previous products.
We have a lot more insitu data than we had during Polder 1 life and also other major coincident satellite measurement to compare with, particularly MODIS, SeaWifs, MSG, MERIS. All these comparisons show the benefit and complementarity of the multi-directional+polarized approach with respect to the spectral approach.

The record of all presentations can be downloaded (in French).

01/2004: Calibration Summary Report

POLDER 2 Calibration phase started in April 2003 and ended in January 2004 with the Polder 2 Calibration review. During this period, intensive efforts were made to characterize Polder 2 radiometrical and geometrical performances, and to perform the in-flight calibration based on a large set of vicarious methods. Results are presented in the calibration rubric.

10/2003: Loss of ADEOS-2 satellite

The Japan Aerospace Exploration Agency (JAXA) failed to receive earth observation data from its Advanced Earth Observing Satellite II, Midori-II, at its Earth Observation Center in Saitama Prefecture at 7:28 a.m. on October 25, 2003 (Japan Standard Time, JST).
At 8:49 a.m. (JST), JAXA checked the operational status of Midori-II, and found it was switched to a light load mode (in which all observation equipment is automatically turned off to minimize power consumption) due to an unknown anomaly.
Around 8:55 a.m. (JST), communications between the satellite and ground stations became unstable, and telemetry data was not received
JAXA's Katsuura Tracking and Communication Station also failed to receive telemetry data twice (9:23 and 11:05 a.m. JST.)

JAXA is currently analyzing earlier acquired telemetry data. The analysis of power generation data by the solar array paddle revealed that generated power has decreased from 6kW to 1kW.

JAXA formed the "Midori-II anomaly investigation team", led by the president of JAXA, to lead the investigation.

Midori-II was launched in december 2002 and this satellite, after one year of tests and validations, operate until now satisfayingly during 10 months. Japanese, american and french (Polder et ARGOS-Next) instruments were on board Midori-II.

The official communication from the JAXA: http://www.jaxa.jp/press/2003/10/20031031_midori2_e.html

While waiting for complementary information from JAXA, the given information can alas let suppose the loss of the satellite.

07/2003: 2 months of Polder 2 data

Polder project has now received 2 months of Polder level 0 data from JAXA: April and May 2003. In order to give an overview of Polder 2 data, level 1 daily syntheses from April, 2 to April, 30 have been compiled in a zip archive.

CNES Calibration team is now processing corresponding level 1 products and plans to end calibration in October as scheduled. First interim level 2 and level 3 products should be available by the end of 2003.

04/2003: First Polder 2 Daily Syntheses

During ADEOS 2 Check out Polder 2 instrument has been set in stand by mode, except during some orbits paths in february (2nd, 9th and 23rd).
These images are syntheses of daily level 1 products subsampled at 1:5; each of them is a color composition of the 865 nm, 670 nm, and 443 nm reflectances respectively coded in red, green and blue.

Note that after the ADEOS 2 check out period, a complete coverage of the Earth will be acquired everyday.

February 2003, 23rd	February 2003, 9th
February 2003, 2nd

02/2003: First Polder 2 images

First Natural- and Polarized-Light Images Acquired by Polder 2

The Polder 2 instrument on board the ADEOS II satellite acquires images in eight spectral bands, from the visible to the near-infrared, in natural and polarized light.

These two images were acquired on 1 February 2003 over the Iberian Peninsula and North Africa in natural light (left) and polarized light (right). Each image is a colour composite of three spectral bands-at 443 nm (blue), 670 nm (green) and 865 nm (red).

(full size image: 200 Kb)   Quicktime Animation (3.2 Mb)

In the natural-light image we can clearly distinguish clouds in white, the sea in dark blue and different types of surface features: vegetation in red and bare soils in brown or yellow.

The image in polarized light is shown with a different scaling. The white arc in the upper left quarter of the image correspond to the rainbow direction, and is indicative of liquid water droplets. Deeper into the corner, color features are the result of single scattering by water droplets and may be used to estimate their size. On the bottom right side, a large polarized reflectance is observed, generated both by atmospheric scattering and surface reflection over the Sahara.

First Sequences of Images Acquired by Polder 2 over Europe and Africa

The Polder 2 instrument on board the ADEOS II satellite acquires images in eight spectral bands, from the visible to the near-infrared, and from different viewing angles.

These "first light" sequences of images (top down and left to right) were acquired on 1 February 2003 over Western Europe and North Africa.

(full size image: 580 Kb)

Each image is a colour composite of three spectral bands-at 443 nm (blue), 670 nm (green) and 865 nm (red). They clearly distinguish clouds in white, the sea in dark blue and different types of surface features: vegetation in red and bare soils in brown or yellow.

The instrument's wide of field of view combined with the forward motion of the satellite enables it to observe the same site from different viewing angles. As a result, we can see significant variations in brightness depending on the viewing direction.

This unique capability will allow Polder 2 to characterize the directional properties of solar radiation reflected by the Earth's surface and atmosphere, leading to more accurate corrections for directional and atmospheric effects, and better determination of target area properties.

01/2003: Polder 2 instrument has been set in stand-by mode 4 days after launch.

Polder ground segment at CNES Toulouse regularly checks supervision data, which are excellent up to now.

12/2002: Polder 2 data acquisition and distribution plan

The schedule for data acquisition and distribution is as follows:

• Start of Polder 2 continuous data acquisition in April 2003
• Start of Level1 products distribution in October 2003 after a 6 months Calibration phase
• Start of validation of scientific products ( level 2 and 3) in June 2003:

Advanced algorithms have been developped for Polder 2 data, from the analysis of Polder 1 results . Comprehensive information and preliminary results are presented in the "scientific products" menu.

Don't hesitate to consult these pages during 2003, they will give you information on the validation progress, and will enable you to display and download some POLDER 2 preliminary scientific products.
(POLDER 1 products processed with 1st generation algorithms are still available).

• Start of level2 and level 3 data distribution during the course of 2004

12/2002: ADEOS II on orbit Check out 2002

Polder will stay in safety mode during launch and initial critical phase on orbit. Polder instrument will be set to Standby mode 5 days after launch. In this mode, all the subsystems of the instrument are maintained inside storage temperature limits and the instrument manager is powered on in order to generate the housekeeping data. In this mode, no mission data are generated.

First data will be acquired about 1 and ½ month after launch. The instrument will be set to imaging mode, taking images during the course of several orbits. These first mission data will be sent by media to the Polder ground segment located in Toulouse Space Center facilities to perform the level 1 processing. The ground segment will also start the full radiometric and geometrical in-flight calibration and performances checking of the instrument based on a set of vicarious methods.
ADEOS II check out phase will last for 3 and ½ month after launch in order to conclude about the system operability. This phase will end with an Initial Checkout Completion Review to authorize the start of the routine operation phase.

12/14/2002: Polder successful launch by JAXA

The Japan Aerospace Exploration Agency (ex NASDA) launched the Advanced Earth Observing Satellite-II (ADEOS-II) by H-IIA Launch Vehicle No.4 (H-IIA F4) at 10:31 a.m. on December 14, 2002 (Japan Standard Time) from the Tanegashima Space Center. The initial azimuth of H-IIA F4 was 122 degrees. H-IIA F4 flight went normally, and it was confirmed that ADEOS-II was successfully separated in 16 minutes and 31 seconds after liftoff.
 

09/2002: Mission Readiness Review

The Polder ground segment will be involved in ADEOS II system operation training. This trainee phase will be performed in August / September 2002 time frame. The objective of this trainee phase is to permit to the operators to validate the operational procedures which will be used during ADEOS II operation in orbit. These tests will involve the total system of ADEOS-II program: ADEOS II Tracking and Control Center, sensors provider control center, ground stations reception, network, ground segment processing. Tests will simulate real operations after launch, to ensure the system's capability (from request of observation to media shipment).

Subsequent to this training phase, Mission Readiness Review will be held at the end of September. During this review will be examined both the mission simulation tests results to conclude about mission simulation test phase (performed during 2000-2001 years) and the training phase results to ensure the total operability on the system.

09/2002: HIIA 3^rd flight

Next important event for Polder is HIIA 3^rd flight. H-IIA Launch Vehicle No. 3 (H-IIA F3) is currently being assembled in the Vehicle Assembly Building (VAB) at the Tanegashima Space Center (TNSC). JAXA is going to launch two satellites, the Data Relay Test Satellite (DRTS) and the Unmanned Space Experiment Recovery System (USERS) by this No. 3 H-IIA Launch Vehicle. Launch is announced by JAXA on September 10th. The success of this flight is of course necessary to guarantee the launch schedule of ADEOS II.

07/2002: ADEOS II launch campaign

After system functional testing, the operation on ADEOS II will carry on with RCS (Reaction Control Subsystem) validation test, mechanical and alignment measurements, and then mechanical final configuration. By the end of September, the satellite will be shipped to the SFA (Satellite Fairing Assembly) building for final assembly, fuel load, and pyrotechnics installation.

Last appointment with the Polder instrument will be around PSR by the middle of October. These Shipment Review conducted at the end of launch campaign satellite tests will review the launch campaign tests result and confirm that the manufacturing process follows on the design and the engineering specifications. This review conducted before the satellite integration in the fairing is the last opportunity to access to the payload. The non-flight items will be removed on this stage. The only Polder non-flight item is an optic protective cover intended to protect the top lens of the objective from pollution and dirtiness. This cover has to be removed as late as possible before launch. So, this cover will be removed just before the satellite integration in the fairing.

Fairing and satellite will then be transferred to the VAB (Vehicle Assembly building) in order to dock the fairing on the 2nd stage. The final count down rehearsal will be then performed before launch.

07/2002: Polder instrument launch campaign

A former launch campaign performed on September 2001 in Tanegashima space center allowed CNES to achieve a final radiometric and geometrical ground calibration on Polder. The instrument was then integrated into ADEOS II payload in order to perform the final system test at satellite level before launch.

Due to an ADEOS II launch delay from February 2002 to November 2002, the launch campaign was interrupted and satellite was stored in Tanegashima space center from December 2001. The Polder instrument remained mounted on ADEOS II payload.

The second launch campaign of Polder instrument started again in July 2002. A specific operation on the Polder instrument has been performed by the Polder team. Polder filter wheel mechanism is designed with a motor using ball bearing whom lubrication is achieved by Mos2 and this Mos2 is sensitive to humidity. After a long period of storage without activation, it was necessary to perform a dry nitrogen sweeping of 48 hours on the instrument in order to dry the ball bearing lubrication before any activation.

After dry nitrogen sweeping, operations on Polder followed on with post storage dedicated functional test and system total test at satellite level including the whole ADEOS II payload. These tests represent the last activation of Polder instrument before launch.

11/2005: Reprocessing over Ocean

Polder 1 and Polder 2 data over Ocean have been reprocessed with several significative improvments:

For aerosols retrieval over ocean, the spatial coverage has been extended by using several means (addition of cases with very few directions and intense aerosol plumes, relaxing of glitter tests...), leading to rather significant changes on monthly syntheses.

Comparison between the two aerosols processing version
Old version

New version

For ocean colour, marine parameters have been slightly modified.

A very good agreement with in-situ measurements has been obtained in both cases, this is presented in the Polder scientific products rubric.

A consistent set of Polder products is now available for a total period of 15 months:
8 for Polder 1 from October 1996 to June 1997
7 for Polder 2 from April to October 2003
The final scientific Polder products can be ordered or downloaded from the Polder website/order desk at: http://polder.cnes.fr

05/2005: End of POLDER 1 scientific reprocessing

01/2003: Update of software tools

Update of software tools: two new interactive visualization tools available.

06/29/2002 : Reprocessing of Ocean Color products

Ocean color and aerosols over ocean products have been reprocessed from new level 1 archive. Significative improvements have been added to ocean color processing.

10/15/2001 : VIPO, a new interactive visualization tool running under IDL

VIPO has been designed to enable users to visualize interactively selected parameters of the various Polder products as well as successive orbits of a given day. Different commonly used projection grids are available.
A rapid powerpoint description is given here in a powerpoint file.

09/15/2001 : New level 1 archive available

After detection and correction of a small non-linearity defect in the Polder instrument the radiometric calibration has been reappraised and a new level 1 processing chain has been applied to all Polder 1 measurements (1996, October 30th to 1997, June 29th). Impact on level 2 and 3 products is still under study.

07/13/2000 : New chlorophyll concentration maps from Polder

A new processing for Polder ocean color 8 months data has been applied.
Chlorophyll concentrations are globally lower and products are cleaner (better clouds filter, more severe optical thickness threshold, better atmospheric correction).

New images of chlorophyll concentration from Polder and corresponding binary data in HDF format can be found at the Scientific Products rubric. Daily syntheses have also been added.

02/07/2000 : The Aerosol Products update

Over Ocean, a new processing has been applied for aerosols over ocean with two changes:

• the cloud screening criteria have been relaxed in order to keep more aerosol events,
• the LUTs have been extended with values of 1.2 for optical thickness.

The main improvement of the product is a better covering of dust transportation over Africa.

Over Land, although aerosol products are not distributed, a very interesting global aerosol index both over land and ocean surfaces is available.
The Scientific Products rubric provides Polder aerosol index images and binary data in HDF and raw format

12/17/1999 : The Scientific Products rubric update

The Scientific Products rubric has been completed with images of main Polder geophysical parameters over the 8 months of ADEOS life. The BRDF data base has been improved. Ocean color images have been updated.
If network is too slow, a new CD-ROM is available through the Polder order desk.

12/06-12/10/1999 : ADEOS and ADEOS II Workshop

An ADEOS and ADEOS II Workshop will be held on December 6-10, 1999 in Kyoto (Japan).
A specific Polder session foreseen on December 7th, in order to present Polder scientific results and evolutions for Polder 2.

03/30/1999 : ADEOS II Research Announcement opportunity

ADEOS II Research Announcement (RA) was available on JAXA/EORC website at: http://adeos2.eorc.nasda.go.jp/JRA/JRAindex.html.
The dead line for the answer is May 31,1999.
If you would like to join Polder International Science Working Team, follow the instructions for submitting your proposal.
For additional information contact: polder@cst.cnes.fr.

02/12/1999 : :BRDF data base available

A BRDF Polder data base has been created with at least 3 BRDFs per IGBP land cover class for 2 seasons (winter/summer).

01/20/1999 : On-line access to sample images

Sample images of the 15 main geophysical parameters derived from Polder observations are presented under the Scientific Products heading.

01/20/1999 : Completion of Polder scientific processing (January 20, 1999)

Level-2 and Level-3 Polder products over the 8 months of ADEOS life are now available to all users. Polder geophysical products have been validated and are available to all users, except aerosols over land (although very promising,they are still in validation phase).

01/18-01/22/1999 : Polder symposium

An international symposium entitled "Aerosols, Radiation & Clouds, Land Surfaces, Ocean Color: the contribution of Polder and new generation spaceborne sebsors" was organized by CNES, the French Space Agency, on January 18-22, 1999 in Meribel (France).

07/02/1998 : Polder data distribution plan

Data processing is being carried out in accordance with the following schedule in terms of processing phases and data release:

04/16/1998 : New release of the MEX and SHOW softwares

A new release of the MEX and SHOW softwares are available at the Softwares page. MEX software now generates Polder data in HDF format.

04/02/1998 : Start of Distribution of Level 2 and Level 3 Products to Polder PIs

Please consult the Polder Catalogue and the Product Description pages for more information.

Polder PIs can order these products using the user services Ordering.

04/02/1998 : Change in Browse and Daily Browse Products Distribution

Browse and Daily Browse products of Polder on ADEOS-1 from 1996-10-30 to 1997-06-29 have been grouped on two specific CD-ROMs.

To get them, please use the user services Ordering.

02/18/1998 : Polder Level-1 Archive completed

Level-1 Polder products over the 8 months of ADEOS life are now available to all users.
Refer to the available products to know which are the latest products.

Consult the daily-browse catalog to visualize Polder daily acquisitions.

01/20/1998 : Improvement of Polder User Services

New ordering interface

The temporary interface opened since July 1997 has been replaced by a more friendly one. A new graphical selection mode called "Daily Browse" is offered for Level 1 and Level 2 products. It is an easy way to select the "best days" according to your specific application.

Software and documentation update

Documentation related to Level2 and 3 Polder products has been added: two publications describing the algorithms and two Data format and user's manuals.

Several software tools have been updated: MEX and SHOW new versions correct a few bugs; the Polder_LIBRARY documentation and examples have been largely completed.

New software tools have been added:

• The LEVEL 1 FORTRAN ROUTINES provide FORTRAN tools for the analysis of Polder level-1 data.
• The ORBITO software is a simple Fortran program which performs approximate orbitography simulations for the Polder instrument onboard ADEOS-1
• The REPROJECT software allows the projection of images, initially in the Polder reference grid, to other common grids

Polder Publications

Scientific articles related to Polder and published in 1997 have been added.

Multimedia Gallery

An animation of Polder sequences acquisitions has been added.

10/01/1997 : Example of one day of Polder acquisition

Image - 2
Test of Daily Browse Polder
cycle=003, orbit=102 to 115, day=1996-11-10
(full size image: 190588 byte)

06/30/1997 : Loss of ADEOS

As you may already know, June 30, 1997 was the very last day on which ADEOS data were recorded. However, ADEOS, launched on August 17, 1996, had observed the Earth for eight months since October 30, 1996, and approximately 20% of the scheduled data have been collected.
Concerning Polder, the instrument had been operating under nominal conditions from October 30 to June 30, so that 8 complete months of Polder measurements will be made available by CNES and JAXA to the international community.

06/01/1997 : Calibration Summary Report

Polder Calibration phase started in November 1996 and ended in May 1997 with the Polder Calibration review. During this period, intensive efforts were made to characterize Polder radiometrical and geometrical performances, and to perform the in-flight calibration based on a large set of vicarious methods. In addition to this novative approach, the bidimensional and polarized characteristics of Polder adds much more complexity to the calibration task.

Considering the image quality already achieved in spite of remaining non compliances with some of the specifications, the calibration review panel decided to authorize the start of Polder level 1 systematic processing and distribution to the users.
Given both the limited amount of data available during the calibration period, and the innovative calibration approach implemented, the continuation of the calibration effort beyond the already achieved performance has been recommended.
In view of the improvements, a reprocessing of the level 1 data at the beginning of the level 2 and 3 systematic processing could be decided.

This short text only intends to give a preview of the results.

09/16/1996 : The First Polder Images

The first images acquired by Polder over France

Polder acquires images through eight spectral filters in the visible and near-infrared spectrum and also through polarizers.
This pair of images shows the same September 16, 1996 first acquisition over France in natural light (left image) and polarized light (right image).

Each image is a blue, green and red color composite of Polder measurements taken at 443 nm, 670 nm and 865 nm.

(full size image: 142435 byte)

On the conventional image (left), marked differences appear between the clouds (in white) and different types of surfaces: vegetation in red, soil in brown and yellow, sea in dark blue. The bright spot in the Mediterranean Sea, west of the island of Sardinia, is the sunglint pattern.

On the polarized image (right) the blue color prevails and the geographic contours can hardly be recognized. This is because the polarized light mainly results from scattering in the atmosphere which increases at shorter wavelengths. The clouds still appear in grey or white and the sunglint spot in the Mediterranean Sea corresponds to a strong polarized signal.

The additional information provided by these original polarized measurements allows a better characterization of the atmospheric contribution to the signal measured at the top of the atmosphere, and thus an improvement in the determination of both surface and cloud parameters of interest.

09/16/1996 : First Sequence of Polder images over Europe and North Africa

This is the first sequence (top to bottom and left to right) of images taken by Polder aboard ADEOS on September 16, 1996.

Each image is a blue, green and red color composite of Polder measurements at 443 nm, 670 nm and 865 nm. Marked differences appear between the clouds (in white) and different types of surfaces: vegetation in red, soil in brown and yellow, sea in dark blue.

A comparison of the same area from one image to the other shows large variations in intensity. In the Mediterranean Sea a bright spot corresponding to sunglint appears to the west of Corsica and moves southwards before disappearing near the African coast (images 1 to 3).

Owing to its wide field of view Polder can take images of a single target successively from different viewing angles. This unique capacity allows the directional properties of the radiation reflected by land surfaces and clouds to be characterized and studied.

(full size image: 379413 byte)