January 23, 2024

Events Archive


2023 was an eventful year for Calipso!

- 27/09/2023: Decommissioning Review (JSG#18)

This review cleared the way to pursue operations, scheduled to end mid-December (with technology experiments on the spacecraft bus followed by passivation of the satellite).

The Decommissioning Review was followed by an event organized in the Leonardo da Vinci building at the Toulouse Space Centre, attended by NASA, marking the end of NASA/CNES cooperation on Calipso over 25 years and the satellite’s 17-year mission. This event gave old hands—still working or former staffers now in retirement at CNES, NASA and research labs—and new hands to get together.

©CNES/Frédéric Maligne

This Decommissioning Review marks the start of the end-of-mission phase (F), which consists in revising science product algorithms, reprocessing and archiving end-products. This phase will end in August 2025.

The next JSG meeting is scheduled for January 2024 (by conference call) for the Mission Operations Close-out Review.

The end of CloudSat’s science mission was also announced on 19 September. The satellite is scheduled to be passivated no later than April 2024. The two missions will therefore have started and finished at the same time…

Lastly, a Calipso science symposium is scheduled from 4-6 June 2024 in Saint-Malo, France.

1 July: Anomaly causes satellite to go into safe mode

An anomaly occurred on 1 July, shortly after the resumption of nominal payload operations with the primary laser. The satellite returned fully to nominal mode on 26 July, leaving insufficient time to resume payload operations before the scheduled mission end date.

Investigations were unable to determine the root cause of the anomaly. However, the most likely explanation could be a malfunction in a DHU power unit (–15 V).

End June: laser switch

In the last week of June, the project switched back to the primary laser, with NASA in attendance, to assess its performance after remaining dormant for 14 years. This operation was successful.

23 May: Key Point to prepare for spacecraft bus end-of-life operations

This Key Point validated the plan for spacecraft bus experiments that will be conducted in the last quarter. Final passivation is scheduled in mid-December.

19 April: End of Science Phase Review (JSG#17)

This review confirmed the end of the science mission on 1 August. Fuel is depleted and in its drift orbit the satellite is unable to deliver enough power to operate the instruments.

The science mission will therefore come to an end on 1 August. CNES teams will nonetheless continue to operate CALIPSO for a few months in order to conduct technology experiments and then passivate the satellite before shutting it down completely at the end of the year.

The review also gave the go-ahead to switch back to the primary laser operational from 2006 to 2009.


November: last MOWG

The last Mission Operations Working Group (MOWG) meeting was held on 16 November at Goddard Space Flight Center (GSFC). These A-Train coordination meetings, taking place twice yearly since 2003, proved most instructive for NASA, CNES and JAXA teams.

3 June: JSG€16 (remotely)

The satellite is operating nominally and the end of the mission was confirmed for September (due to waning solar array power).

Low-energy shots with the operational laser are still very much up and down.

CloudSat is continuing manoeuvres to join Calipso and re-form the A-Train. The formation should be in place again by end November.

Lastly, 2022 saw a record number of scientific publications using Calipso data with 430 papers, taking the total since the satellite was launched to nearly 4,200.


May: JSG€15 (remotely)

The spacecraft bus is behaving nominally, with all redundancies available. Power margin estimates confirm a scheduled mission end date in late 2023.

Low-energy laser shots are broadly stable in terms of frequencies and level. A laser switch is envisaged in September.

For the ground segment, the number of S-band passes was reduced from five to four daily passes in 2021, as agreed by CNES and NASA. Given the satellite’s age and behaviour, sustainment operations have been scaled back.

Lastly, more than 3,800 publications citing Calipso have come out since 2007.

2020 events

CNES REDEM and NASA Senior Review

The Calipso mission is set to continue the outstanding scientific results of the last 14 years, with an extension for three more years:

The 5th Calipso REDEM Mission Extension Review on 18 May approved a final extension for a further three years (2021-September 2023). CALIPSO was hailed all round as an outstanding mission, with a very positive assessment from the TOSCA Earth, oceanography, land surfaces and atmosphere group. For 14 years, the mission has delivered excellent scientific results, confirmed by the IPCC and more than 2,900 research publications to date, a number that is increasing every year with 363 in 2019 alone—a new publication every day!

From a science standpoint, the arguments for continuing the mission are many: extending the cloud-aerosol climate data record; observing remarkable and extreme phenomena (volcanoes, wildfires, the impact of the Covid-19 pandemic on aerosols); new dynamics (assimilation of aerosols, the link between aerosols and pollution); overlap with other missions (Aeolus 2018, Earthcare 2022) and major scientific surveys; and preparations for ACCP/MESCAL. CNES and NASA decision in September.

The satellite and payload also remain in good shape:

  • The main lidar instrument has been experiencing very frequent low-energy laser shots within and around the South Atlantic Anomaly (SAA) region since 2017, but also outside this zone and to an increasing extent over the last year, meaning that a switch of lasers is likely in the first half of 2021.
  • Following an anomaly, the Wide-Field Camera (WFC) has been shut down since March 2020. The camera’s data have been valuable in attaining CALIPSO’s science goals over the last 14 years, and losing it has not significantly impacted the rest of the mission.
  • The performance of the Infrared Imager remains nominal.

The C-Train formation should be able to be maintained for at least three years.

A three-year extension of operations is therefore possible and desirable, plus two more years for science and completion of data processing.

2019 events

5-7 June: The spring meeting of the Missions Operations Working Group (MOWG) for the A-Train/C-Train constellations organized by CNES in Toulouse was a huge success.

The MOWG convenes twice a year, bringing together mission operators and managers—60 participants from France, the U.S. and Japan—to coordinate in-orbit operations for these constellations.

  • The first day was devoted to a review of each mission, with introductions from the representatives of CNES (P. Tabary), NASA HQ (E. Ianson) and ESA (Kate Symonds) on current and future Earth-observation missions.
  • The second day was focused more on operations and conjunction assessments.
  • The third day was given over to a tour of CNES for MOWG members, starting at the ATV-CC and taking in the mini- and microsatellite control centres, COR, OCC, CAESAR, AIT, Mars and rover facilities.

3-4 June: 12th CALIPSO REVEX at CNES in Toulouse, attended by teams from NASA LaRC and French research laboratories: IPSL, LATMOS and AERIS/ICARE.

Calipso turned 13 on 28 April and the current mission extension runs through to end 2020.
Since October 2018, the satellite has left the A-Train to join its partner CloudSat (a complementary radar satellite) 17 km below the A-Train orbit. Tandem measurements from CloudSat and Calipso have since resumed after a hiatus of 9 months, to the great satisfaction of the scientific community.

Space segment
Everything is nominal except for the propulsion system, where gas bubbles have been detected in the fuel tanks. Enough fuel remains for a single 60 m/s manoeuvre, after which thrust amplitudes will be unpredictable.
The decision was taken to cease satellite manoeuvres—except for one last avoidance manoeuvre if required—but to pursue the mission as the orbit will allow the satellite to re-enter in less than 25 years and CloudSat is synchronizing with Calipso. This option secured approval under the French Space Operations Act (FSOA).

The power level of the main lidar instrument remains stable outside the SAA zone (i.e., 96% of the time) and the other two instruments are working perfectly.
Medium-term projection: the platform power limit will be reached by September 2022 (as a result of the drift of the satellite’s local time, which will no longer be controlled), after which we will need to assess solutions for managing power if we want to extend the mission further (action at next JSG meeting in November).

The 13-year series of data provides a reference point for future missions (ESA/EarthCARE, NASA/ACCP). The high number of science publications shows the importance and sustained interest of the international scientific community.
Numerous collaborations with other missions—CATS, Ice-Sat2, Aeolus, Sage III, Osiris limb-scattering—were accomplished this year.
The latest versions (V4) of both lidar and IIR products are significantly improved. IIR has played an increasingly important role, enabling major contributions, especially for cirrus clouds.
The AERIS/ICARE data centre made a strong contribution this year to the Calipso mission (with a new level 2 version of the IIR product) and its collaboration with NASA LaRC’s Atmospheric Science Data Center (ASDC) is excellent.
It is now proven that assessment of the cloud and aerosol radiation balance is better when using combined products such as C3M, 2BFLXHR-Lidar or Dardar, SODA.

The arguments for pursuing the mission for as long as possible are not lacking, given the significant advances to be continued on the radiative effect of clouds and aerosols, which is a key component of climate research. Calipso-CloudSat observations are unique, and no equivalent mission will be in orbit until EarthCARE, expected to come on stream in 2022.

2018 events

Autumn: Calipso moves from A-Train to C-Train orbit

9 November: annual CNES/NASA JSG meeting. Mid-year review of the mission and space segment, and first results since the change of orbit: the outcome is positive and the Calipso and CloudSat missions are once again operating together to acquire tandem measurements after being apart for 9 months. Science results are excellent.

13 September to 17 October: operations to move from A-Train to C-Train orbit. Operations go according to plan, with the exception of the final inclination manoeuvres, which have to be aborted due to a thruster nozzle anomaly. Calipso and CloudSat are nevertheless perfectly positioned in the C-Train orbit. The satellite’s altitude was lowered to 688 km.

6 September: CNES/NASA Calipso JSG meeting to confirm the decision to change Calipso’s orbit and join CloudSat in the new C-Train orbit and give go-ahead for start of operations.

25 July 2018: Calipso/CloudSat Orbit Change Reconfiguration Review

NASA review to examine moving the Calipso and CloudSat missions to the new C-Train orbit less than 17 km from the A-Train orbit. Assessment of operational impacts and risks, as well as science mission impacts: the review clearly approved this orbit change, concluding that Calipso will better advance the mission’s science goals in tandem with CloudSat in the C-Train than by remaining in the A-Train without CloudSat.

From an operational perspective, the orbit change can be accomplished from September 2018, with no risk or extra cost, and no change to the nominal mission lifetime bar a short interruption of about 1 week. The science value of doing this is undeniable:

  • Pursuing tandem observations by Calipso and CloudSat is vital to characterize the main parameters affecting cloud-climate variability, as cloud observations need to be performed simultaneously due to the timescales involved.
  • This change will ensure continuity and consistency of combined CloudSat-Calipso time-series data products through to 2021.
  • Calipso was designed to accomplish its science goals in the A-Train, for which the Imaging Infrared Radiometer (IIR) and Wide-Field Camera (WFC) were included in the payload.
  • All Calipso science will be maintained. Synergies between Calipso-MODIS aerosol data will be retained, as aerosols are more uniform spatially and temporally, have a longer lifetime and can tolerate time differences on the order of 1 hour, compatible with the new orbit geometry. Ten percent of MODIS-Calipso cloud synergies will be retained and the remainder will be substantially offset by WFC and IIR.
  • Calibration/validation with future missions remains a possibility as this is independent of the orbit.
  • Calipso-CloudSat will orbit underneath MODIS’s swath, thus affording a wide range of viewing angles, which will prove useful for studying the impact of higher viewing angles.
  • There will be no notable impact on data/products (no reprocessing or version change will be required)
  • Lastly, should CloudSat be lost, scientific exploitation of the satellite mission is the same for both orbits (A-Train and C-Train).

16/05-17/05/2018: 11th CALIPSO REVEX in Dulles (U.S) with NASA LARC, CNES and AERIS/ICARE teams

The review was successful as regards the full capacity of the space segment (bus, ground segment and payload) as well as the extent of science accomplished, which has gone from strength to strength over the 12 years of the mission. Three key points are worthy of note:

  • Laser performance: contrary to what was expected a year earlier, the primary laser’s performance is still good outside the SAA zone (less than 1% of laser firings are affected) and the mission will continue to operate with this instrument as long as its performance remains satisfactory. Switching to the back-up laser is therefore no longer a consideration for the time being.
  • A presentation was given explaining the strategy and science value of changing Calipso’s orbit to continue tandem measurements with CloudSat. This option was given the green light. The French scientific community clearly expressed its preference for this option (see document attached), for NASA a Mission Reconfiguration Review is still required before a final decision by JSG CNES-NASA.
  • A presentation was given of the platform technology experiments that will be conducted after the end of the Calipso mission to characterize and analyse nozzles, measure battery performance and perform end-of-life RAM analysis.

2017 events

December: CloudSat leaves A-Train

Calipso’s companion satellite leaves the A-Train after the failure of a reaction wheel impairs its emergency manoeuvring capability.

This marks the start of a long scientific evaluation period, with teams seeking orbital strategies and conducting engineering analyses to decide whether Calipso should join CloudSat in a new orbit to pursue their tandem mission.

November: Technological experiments selection for the end of the Calipso mission

July: The latest version of level 1 IIR Standard data (V2-00) is now available for US and French data centres (ASDC and AERIS/ICARE)

Version 2.00 of the IIR Level-1 product is the first major revision since the initial release in 2006. The calibration procedure has been adjusted to reduce known small seasonal calibration biases in the Northern Hemisphere, which were caused by thermal drifts synchronized with the elapsed time since the night-to-day transition.

May: CNES REDEM and NASA Senior Review for CALIPSO.

After 11 successful years of science operations, CNES and NASA agreed to extend the Calipso mission for another three years (2018-2020).

In addition to maintaining the French scientific community’s dynamic and structure in the field of space lidar, four essential objectives have been identified to justify a three year extension:

  • Extending Calipso’s time series: a major requirement for climate change studies. An observation period of over 10 years is necessary in order to detect potential trend on relevant variables. Contributing to World Climate Research Programme (WCRP) projects such as CMIP6 is also a possibility. These exercises provide content for the Intergovernmental Panel on Climate Change (IPCC) reports. An extended observation period also allows for richer statistical sampling and increases the chances to observe one-off events such as volcanic eruptions.
  • Observational continuity with future missions: extending the Calipso mission to 2020 will ensure continuity with the CATS (NASA, lidar aboard the ISS, already in orbit), ADM-Aeolus (ESA, planned for launch in early 2018), and possibly Earth-Care (ESA, launch due in August 2019) missions. ESA's Aeolus and EarthCARE missions will operate lidars at different wavelengths to CALIOP (355 nm instead of 532 and 1064 nm), so data will have to be recalibrated in order to provide a continuous series from active sensors. A longer simultaneous observation period will provide better comparison and analysis of specific data from each of these missions. Calipso will also improve these missions’ Cal/Val exercises (as suggested in a co-written letter from the Aeolus and EarthCARE mission scientists).
  • Contributing to several upcoming scientific campaigns: EUREC4A (S. Bony, the Field Study, 2020), EXAEDRE (Eric Defer, 2018), MOSAIC (Arctic, 2020)
  • Developing new applications: Two new and very promising research activities are growing rapidly: data mining using air quality prediction models (the Copernicus C3S and CAMS services, as well as the French national weather service Météo-France, have expressed great interest for this field), and assessing the oceanic surface layer’s optical properties (with strong momentum from the French OCEAN community in favour of an ocean colour application).

When it comes to the space segment of the Calipso mission, the satellite has been in orbit for over 11 years; every redundancy is still in place and the payload is still operating at full capacity with comfortable leeway for both temperature and power. Calipso will be able to stay its course on the A-Train at least until 2019, and then slowly drift eastward from Aqua, but without any effect on the satellite or its mission. The WFC and IIR instruments remain fully operational and the lidar’s performance is generally excellent. However, low-energy impulses can be observed in the SAA above the planet’s poles, and the laser’s pressure levels lead to Corona impulses such as the one observed on the primary laser in 2009. Therefore the current laser should soon be switched off to be replaced by the primary laser, which should be out of the critical pressure zone.

17 and 18 May 2017: 10th CALIPSO REVEX at CNES in Toulouse with NASA’s LARC teams and French scientists from contributing laboratories (AERIS/ICARE, LMD, IPSL)

The review was a success for the space segment (spacecraft bus, ground segment, payload) as well as for the scientific part of the mission which has been prolific for the past 11 years in orbit.

The REVEX also showed the good level of readiness displayed by the instruments, operations, and science teams for the upcoming laser change planned for autumn.

18-21 April: 3rdA-Train Symposium held in Pasadena, California


For over a decade, the Afternoon (A-Train) Satellite Constellation has brought together a rich array of instruments to better understand Earth’s changing climate and environment. The 3rd International A-Train Symposium was an opportunity to learn and exchange information about A-Train scientific breakthroughs and to highlight how Earth science has benefitted from the long, continuous, multi-sensor data set.

2016 events

22 November 2016: 10th Joint Steering Group meeting

Components review (platform, payload and science) and preparation of the next mission extension (2018-2019) which will be evaluated in spring 2017 (CNES REDEM / NASA Senior Review).

8 August 2016: New versions (V4.10) of standard Lidar Level 1 and Level 2 data products are available both at the US and French data centres (ASDC and AERIS/ICARE).

V4.10 Level 1 CALIOP: algorithms unchanged since V4.00, but improved digital models and weather forecasts.

V4.10 Level 2 CALIOP: major revision since 2010 with the correction of numerous artefacts and significant enhancement of both content and quality of the science data. Moreover, V4.10 features a merged layer product that compiles spatial and optical properties of cloud and aerosol layers in a single file (https://www-calipso.larc.nasa.gov/).

8-10 June 2016: "CALIPSO-CloudSat Ten-Year Progress Assessment and Path Forward Workshop" in Paris at the "Maison des océans" to celebrate 10 years of scientific measurements.

More information on this workshop at https://calipsocloudsat.sciencesconf.org/. Objectives:

  • Present the scientific breakthrough after 10 years of observation with the two complementary CALIPSO and CloudSat missions.
  • Highlight the synergies with other missions displayed by the A-Train and to underline the benefits of such an international partnership.
  • Prepare the future.

The French celebration of the CALIPSO measurements' 10-year anniversary was chaired by Jean-Yves La Gall in front of numerous French (CNRS-IPSL, Thales Alenia Space, SODERN, AERIS/ICARE) and American (NASA) partners, see the CNES Press Release

28 April 2016: Calipso at 10: Calipso celebrated its 10 years in orbit on 28 April (Press Release UPMC/J. Pelon).

This event was celebrated on 21 April at LARC (see NASA Press Release) with teams from NASA, Ball Aerospace, CNES and IPSL.

19-20 April 2016: 9th CALIPSO Operations Review, at NASA Langley Research Center (LaRC) in Hampton, USA

Again, a very positive outcome for this year for both the ground segment and the scientific aspects: 1,650 publications and counting, and the combined LIDAR+CloudSat (DARDAR) measurements are in the top 10 products used at the AERIS/Icare data centre. Since October 2015, measurements are performed for "ocean colour" applications, at the rate of one orbit every 15 days over the Pacific Ocean, the satellite being tilted 30°: the first results are very positive, the scientists want to pursue this over different seasons, over the Atlantic as well as at high latitudes and over polar areas.

2015 Events

19-20 May and 26 May 2015: 8th CALIPSO Operations Review, 3rd Mission Extension Review (REDEM) at CNES Toulouse

After nine years in operation, satellite and payload performance are still excellent and the Calipso mission is considered a real success.

Thanks to their high-precision vertical resolution, Calipso observations are a unique contribution to the study of clouds and aerosols, and to the validation of climate models, as highlighted by the latest IPCC report.

A new two-year extension of the Calipso mission in the A-Train is confirmed for 2016-2017, with the following objectives:

  • Long-term observation needed to understand the role of clouds and aerosols in the Earth's climate
  • Calipso/OCO-2 dual observations to study the influence of aerosols on CO2 restitution
  • Overlap or continuity with the CATS, ADM-Aeolus, EarthCare and SAGE III missions
  • Estimate the contribution of lidar measurements to ocean colour investigations, through a survey campaign using the 30-degree off-axis capability to observe phytoplankton while minimizing specular reflections.

24 February 2015: Sand travelling from the Sahara to the Amazon as seen by Calipso

Read the full story on NASA's website.

2014 Events

27 November 2014: CALIPSO just passed the 5 billion laser shots mark:

1.62 billion shots for the primary laser and 3.38 billion for the secondary laser (nominally used since 2009), for a total of 100 seconds of light emission for 8 years and 7 months of data in orbit!

25 November 2014: 9th Joint Steering Group meeting

Nominal mission continuation, we are moving towards a future mission extension (2016-2017) with Calipso still a part of the A-Train.

13 November 2014: New version (4.0) of LIDAR level 1 scientific products

This updated version substantially improves both the 532-nm and 1,064-nm calibration accuracies. Part of the mission data is already available in this version, more information on the LARC website

4-6 November 2014: Cloudsat/Calipso Science Team meeting, Alexandria, USA<

Presentations of work done by the Calipso-CloudSat 2014 science team towards improved use of observations (precipitations/snow, and clouds/clouds-aerosols). The programme is available on the conference website.

11-12 June 2014: 7th CALIPSO Exploitation Review at CNES, Toulouse

After eight years of service, the platform and the payload are in excellent shape and all redundancies are available. From a scientific perspective, Calipso products are now classified as "Climate Data Record".

2013 Events

19 November 2013: 8th Joint Steering Group meeting / confirmation of a new two-year extension of the CALIPSO mission

After the Senior Review processes for NASA and the REDEM for CNES, the two agencies declared that they were again in favour of an additional two-year extension of the mission (2014-2015). CNES and NASA will thus pursue their productive partnership on the CALIPSO mission.

From now on, due to the shutdown in October 2013 in USA, the formal review cycle between CNES and NASA is reversed: JSG (Joint Steering Group) in autumn and REVEX (REVues d'EXploitation) in May/June.

28 June 2013: Mission Extension Review Steering Committee (REDEM)

The REDEM Steering Committee approves a new two-year extension of the CALIPSO mission (2014-2015) and anticipates two more years after that.

2012 Events

18-19 October 2012: Sixth CALIPSO Exploitation Review in Greenbelt, USA

After six years, platform and payload alike are performing nominally. On the science side, the number of scientific users as well as publications continues to progress significantly.

3 July 012: Active observations from space, a new key to understanding the complex relationships between clouds, aerosols and radiation.

A joint CALIPSO/CloudSat/EarthCARE satellite missions workshop was held from 18-22 June 2012 at the Institut Océanographique de Paris. This workshop brought together over 200 of the world's leading scientists working to improve our understanding of Earth's atmosphere and climate using advanced spaceborne remote-sensing technologies. The workshop showcased many remarkable achievements with the CloudSat and CALIPSO data, which are revolutionary in their ability to observe the vertical distribution of clouds and aerosols.

Read the full CNES-CNRS Press Release.

18-22 June 2012: A joint workshop on "The Role of Clouds and Aerosols in Weather and Climate" of the NASA/CNES CALIPSO, NASA/CSA CloudSat and ESA/JAXA EarthCARE satellite missions will be held in Paris, France.

28 April 2012: CALIPSO has just celebrated its 6th anniversary in orbit and is successfully pursuing its atmosphere-observing mission.

2011 Events

21 November 2011: Go-ahead from FSOA bureau for CALIPSO mission extension.

10/19-10/21/2011: A-Train Mission Operations Working Group (MOWG) meeting in Biarritz, France.

This year, CNES hosted the A-Train constellation MOWG meeting. During this MOWG, the possible return of the CloudSat satellite into the A-Train constellation was discussed at length, notably its possible impacts on CALIPSO mission operations. A process was established setting out the main steps required to analyse this return, as well as formal decision reviews.

17-18 October 2011: 5th CALIPSO Exploitation Review in Biarritz, France.

This 5th REVEX highlighted the excellent operational results of the satellite and the ground segment and confirmed the extension of operations through to end 2013.

26 September 2011: NASA confirms CALIPSO mission two-year extension

CNES and NASA decided to continue their cooperation on the CALIPSO mission and confirmed its extension by two more (2012-2013).

8 September 2011: Signature of new Implementing Arrangement (IA) between CNES and NASA.

This new IA signed between CNES and NASA provides for continued cooperation between the two agencies on the CALIPSO mission. It replaces the MoU signed on 18 June 2003, which was about to expire.

26 May 2011: Mission Extension Review Steering Committee (REDEM).

The REDEM Steering Committee gave  the go-ahead for a two-year extension to the CALIPSO mission (2012-2013). At the same time, a senior review process is ongoing at NASA and will respond by the end of August about this extension. On the CNES side, a new ruling from the FSOA bureau is expected to ratify this extension.

4 April 2011: Mission Extension Review (REDEM).

End 2010, the scientific community asked for a two-year extension of the CALIPSO mission. CNES processed this request and presented the results at the REDEM on 4 April. Since the French Space Operations Act (FSOA), or "Loi d'Opérations Spatiales" (LOS)), came into effect in December 2010, mission extensions must comply as far as possible with the criteria set out in the new act and with rulings from the FSOA bureau.

2010 Events

25-28 October 2010: International Symposium on the A-Train Satellite Constellation 2010, New Orleans, USA

The International Symposium on the A-Train Satellite Constellation 2010 follows and expands on the first A-Train Symposium held in Lille, France in 2007.

It aims to provide a forum to exchange information on the latest scientific advancements using multi-sensor measurements from the A-Train. An additional objective of the symposium is to better inform new and present users on recent enhancements to A-Train data sets and subtleties related to their use. Because the instruments employ different measurement techniques, merging observations and/or data products is often challenging. Consequently, another important objective is to highlight key issues and strategies for combining the diverse measurements.

7-8 October 2010: 4th CALIPSO products Exploitation Review in Orlando, Florida, USA

4-6 October 2010: MOWG in Orlando, Florida, USA

May 2010: New version (3.01) of CALIPSO Science Products

The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite mission is pleased to announce the immediate public release of its version 3.01 cloud and aerosol data products. The new release includes all Level 1 and Level 2 products derived from the Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) measurements. At present, no new data products are being released for the Imaging Infrared Radiometer (IIR) and the Wide Field Camera (WFC).

The quality and quantity of the information provided in the CALIOP version 3 data products are substantially improved over previous releases. These improvements are attributed to a number of factors, including significant enhancements to the daytime calibration procedures; incorporation of advanced probability distribution functions for more reliable separation of clouds and aerosols; implementation of a new algorithm for determining cloud thermodynamic phase; refinements to layer base detection for boundary layer aerosols; and several important corrections to the CALIOP extinction retrieval code. Data usability is greatly enhanced by the addition of numerous diagnostic and quality assurance parameters. In addition, several new optical parameters (e.g., ice-water content/path and particulate depolarization ratios) have been added to the Level 2 products, and range-resolved uncertainty estimates are now provided for all optical profile data. The organization of the CALIOP version 3 profile products has changed also significantly. In particular, the aerosol profile products have been completely restructured, and now are reported on the same spatial grid as the cloud profile products. The horizontal resolution of the cloud and aerosol profile products is now identical to the horizontal resolution of the 5-km cloud and aerosol layer products, thus enabling unambiguous identification of the profile data associated with each layer reported in the 5-km layer products.

The CALIOP version 3.01 data products are presently available for 2006 and 2007 at the Atmospheric Science Data Center (ASDC) (https://eosweb.larc.nasa.gov). These products will also soon be available at the ICARE data centre in France (http://www.icare.univ-lille1.fr).

Additional data for 2008-2010 will be posted at both facilities as they are processed over the next few weeks.

28 April 2010: Fourth year in orbit for CALIPSO.

Since the laser switch in March 2009, the mission is being pursued nominally and laser performance is excellent.

Calipso observes the ashes plume above France on April 17th, 2010 - © NASA
Calipso observes the ash plume over France on 17 April 2010 - © NASA

The CALIPSO mission, initially scheduled to last three years, has been extended for two more years (2010-2011). For all the teams that contributed or are still contributing to the success of this mission, this is a cause for celebration and a huge success.

2009 Events

May 2009: Third anniversary in orbit for CALIPSO on 28 April. Begins its fourth year notably thanks to its back-up laser!

March 2009: Complete success for CALIPSO laser switch campaign

The laser switch campaign initially scheduled from 24 February 2009 to 18 March 2009 has been put back to 6 March 2009 to 19 March 2009 after the anomaly recorded on 16 February 2009 on laser 2. The laser 1 switch operations were performed in close cooperation with LARC and enabled a nominal restart of the mission on 17 March 2009. Laser 2 was definitively shut down on 6 March 2009.

Read the full NASA-CNES joint press release.

2008 Events

11/2008: CALIPSO in the press

Interview with the mission Co-PI (in French).

10/2008: 2nd CALIPSO Exploitation Review on 6 and 7 October, followed by A-Train Mission Operations Working Group meeting (MOWG) on 8, 9 and 10 October in Norfolk, Virginia (USA).

28 April 2008: Second year in orbit for CALIPSO!

001/2008: CALIPSO level 2 Lidar products are available at ASDC (Atmospheric Science Data Center)and notably include the extinction and backscattering optical properties of clouds and aerosols, cloud phases (ice, liquid) as well as aerosol types.

These products began to be distributed on 28 January and data reprocessed since 13 June 2006 are already available.

2007 Events

11/2007: Since 28 November 2007 19:24:20 UTC, Calipso has definitively changed its tilt (pitch from 0.3° to 3°) following tests performed from 6 to 15 November  2006 and from 21 August to 7 September 2007.

To ensure the best possible footprint overlap, CloudSat has modified its position with respect to Calipso, moving 5 seconds ahead of Calipso.
New A-Train phasing

10/2007: An A-Train Lille Symposium 2007 was held in Lille - Grand-Palais - from 22 to 25 October 2007

The goal of this international meeting was: "Using A-Train observations and modelling to understand aerosols and clouds"

28 April 2007: CALIPSO's first successful year in orbit!

Preliminary results

03/2007: CALIPSO data with browse facility are available on the AERIS/ICARE website

01/2007: Examples of level 1 qualified products from the Infrared Imager.

Level 1 processing combines raw measurements from the IIR with calibration data and attitude and navigation measurements to provide radiances directly usable by the scientific community. The quality of level 1 products has been optimized during the commissioning phase, removing the image of the Moon in deep-space views, finely determining the location of IIR images, and correcting normalization of IIR channel spectral responses. Since the release in early December, Level 1 images are now centred on the lidar ground track. Here are some examples.

2006 Events

12/2006: Public release of CALIPSO Data Products

The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite mission has started distribution of its data products. This data release consists of data beginning in mid-June 2006 and includes Level 1 radiances from each of the instruments. This release also includes the lidar Level 2 vertical feature mask and cloud and aerosol layer products. CALIPSO data are available through the Atmospheric Science Data Center (ASDC) at NASA Langley Research Center and can be accessed at the following URL: https://eosweb.larc.nasa.gov/project/calipso/calipso_table

12/2006: A-train operational coordination meeting at NASA

10/2006: CALIPSO science team meeting is scheduled for 3-5 October  2006 in Annapolis (MD)

09/2006: The Operation Handover Review will take place on 7 September  in Newport News.

This will close out the commissioning phase and hand over responsibility to LaRC’s Science Operations team.

07/2006: One day (15 June 2006) of lidar profiles was released to the science team on 27 July.

07/2006: A press release from 26 July presents the first data.

07/2006: The CALIPSO In-Flight assessment Review was held on 11-12 July in Toulouse.

06/2006: CALIPSO has joined the A-Train.

IIR first image

CALIPSO operations are nominal with all spacecraft systems in good health. The three science instruments have been powered up and the initial assessment of data is positive. Here is one of the first images from the Imaging Infrared Radiometer (IIR) provided by CNES.
(Credits: NASA for the Terra/Modis images and CNES for the Calipso/IIR images).
Learn more (in French)

04/2006: Successful launch on 28 April 2006 (replay)

launch direct
Calipso launch

2005 Events

05/2005: Satellite shipment to launch site

2004 Events

09/2004: Thermal/Vacuum test completed

05/2004-06/2004: Mechanical tests on the satellite

03/26/2004: Platform and payload functional tests

03/01/2004: Satellite assembly

02/12/2004: Payload delivery at Cannes