1 Program:ROSA Mission Event:1° ASI-EUM ASI-meeting Date:4-5 February, 2009 ROSA Future developments and possible ASI / EUMETSAT cooperation.

1Program:ROSA MissionEvent: 1° ASI-EUM ASI-meetingDate: 4-5 February, 2009

ROSA Future developments and possible

ASI / EUMETSAT cooperation


Present RO Missions

Considerations on RO

About 4000 RO data “ available” just now!


The results achieved by the RO instruments aboard of the above missions

have demonstrated that the RO Technique is:

• Simple

• Mature

• Great scientific value

• Potentially of future social/commercial value



In particular, the FORMOSAT-3/COSMIC Constellation, a Scientific

mission based on 6 satellites equipped with only RO Instruments,

has demonstrated how useful can be the RO data in the field of:• Weather Prediction ( assimilation of the RO data in the NWP)

• Climatology

• Space Weather

The Last generation of RO Instruments , like GRAS and ROSA, can

improve the above applications (for instance: sounding very close to

the Earth surface) and add new ones like Geodesy/Gravitation using the

POD (Precise Orbit Determination) data.



Type of RO Missions

Scientific Missions: Missions of Opportunity:

Champ,Grace, Metop-A,TerraSAR-X, ROSA etc. Dedicated RO Constellation:

COSMIC, etc

Commercial/Operative Missions Constellation of Opportunities:

IRIDIUM, Globastar etc Dedicated RO Constellation :

CICERO



Name Receiver Launch Soundings/day Status OCEANSAT-2 ROSA 2009 300 planned

Megha Tropiques IGOR 2009 500 planned TANDEM-X IGOR ~2010 200 planned KOMSAT-5 IGOR ~2010 500 planned

Aquarius/SAC-D ROSA 2010 600 planned METOP-B GRAS 2011 600 planned CICERO Pyrix

(IGOR 2) 2011(?) 12,000/24,000

(12/24) Phase B

EQUARS IGOR 2011 500 uncertain FORMOSAT3-FO Pyrix 2012 10,000

(12)

TBD ROSA 2 2012 (?) 600 TBD Iridium Pyrix 2013 33,000/66,000

(66) proposal

GEMSS (India) Pyrix 2013(?) 3000 (6)

proposal

China Earthquake TBD 2013(?) 600 proposal METOP-C GRAS 2016 600 planned

Planned RO Mission



Why so many RO missions ?

Main Applications:

• Climate

• Weather

• Space Weather

• Geodesy



Climate Applications

Long-term climate trend detection Seasonal climate forecasting Climate process&model studies/testing

Long-term measurement stability (< 0.1 K ) Calibration with other Instrument (IR/MW) Accurate global sampling

12-18 RO Receivers, uniformly distributed and constantly in operation should be sufficient



Weather Applications

Global Forecast Statistics Severe storm forecasting (evolution, path etc)

High sampling density

< 1-hour latency

How many RO events are necessary?



Assumptions for thumb calculations: GPS constellation : 28 satellites LEO satellites orbit: 800 km Earth R: 6380 km RO instruments : rising and setting occultation

With the above assumptions

1 RO instrument can see : ~500 occ/day

and when GLONASS and GALILEO will be available 1 RO instrument can see : ~1500 occ/day



#ofLEO’s

GNSS Transmitters

# of occultations Average# ofoccultations on a surface of 500km by 500km

Average Horizontal Spacing (km)

1 28 500 0.2 1140

1 28+28+28 1500 0.6 657

6 28 3000 1.2 464

6 28+28+28 9000 3.5 268

24 28 12000 4.6 232

24 28+28+28 36000 13.9 134

173 28 86377 33.3 87

173 28+28+28 259131 100 50



Daily Storm Sampling Density100 occ / day

Hurricane Katrina28 Aug 2005

Hurricane Katrina28 Aug 2005

by Thomas P. YunckGeoOptics

LLC



• when the 3 major GNSS constellation (GPS,GLONASS and GALILEO) will be operative, a reasonable number of occ/day will be possible starting with only 24 LEO satellites.

• to have an Horizontal spacing of about 50 km it is necessary a very large number of LEO satellites: only commercial constellations like Iridium and Globastar could meet requirement.

• the G/S to meet a latency of <1h for so large number of LEO is possible but will not be easy.



Space Weather Applications High-res mapping of 3D electron density Maps of ionospheric irregularities Geomagnetic storm forecasting and early warning

High sampling density in a short time

High altitude sampling to ~700 km

Observations of ionospheric features

Short time of latency time

Space Geodesy Applications Gravity field determination and mapping

High sampling density

High precise measurements of the Signals Phases



Some considerations:

• The GLONASS constellation will be fully operative for 2011(?)• The GALILEO constellation will be fully operative for 2013(?)• The GNSS Chinese Constellation will be operative for 20xx (?)• Use not only the Refracted GNSS radiation beams but also the Reflected/Scattered ones• A new generation of RO Receiver is necessary. As baseline could be used the following

requirements: ITAR freeminiaturizedSW radio technologiesGPS/GLONASS and GALILEO compatibilityL1,L2 and L5 frequenciesnew antenna design as optional the integration with a scatterometer/altimeterc module and/or a FIR Fourier interferometer etc.

ASI made the PHASE A of the ROSA II ( Phase A closed in October, now in competition for the next phases):

• A new generation of RO Retrival processing chain is necessary? Partially or Totally?



Have been the the main objectvies of the RO achieved and how? For an operational service, like the meteorology a very large number of

instruments is required. Only the use of very large constellations (IRIDIUM and or GLOBASTAR) or new ideas can help in this case.

For the Climatology, Space Weather and Solid Earth a small constellation (12-18) can ben sufficient.

NASA /NOAA have in the next future the following plan : A constellation of 6 satellites + to install a RO Receiver on every available LEO mission.

In EUROPE only 2 Institutions (EUMETSAT and ASI) have developed an own receiver for RO : GRAS and ROSA.

In rest of the world there is only the JPL (or some slight variation) receiver.



In the next future EUROPE will have the most powerful civilian GNSS constellation. But …

It is desirable that European institutions can promote or design some worldwide (or only european) initiative on the Radio Occultation ( with or without integration with a GPS network on ground)

ASI and EUMETSAT can do something to this scope?



Short terms ASI/EUMETSAT cooperation

Availability of a set of data to be processed by ROSA ROSSA

Availability of the ROSA data

Periodic meeting ( 1-2 per year)


1 Program:ROSA Mission Event:1° ASI-EUM ASI-meeting Date:4-5 February, 2009 ROSA Future developments and possible ASI / EUMETSAT cooperation.

Documents

ro slide

asieum asimeeting date

ro technique

ro events

ro receivers

rosa mission event

dedicated ro constellation

ro data available