Th ICI i fThe ICI series of Space Weather RocketsSpace Weather Rockets

Jøran MoenUniversity of Oslo

Also at The University Centre in Svalbard

GPS ERROR SOURCES

Courtesy of Alfonsi

IONOSPHERIC EFFECTS ON GPS SIGNALSL-band scintillations

Ionospheric irregularities can produceshort term phase and amplitudefluctuations in the carrier of the radiowaves which pass through them. Theseeffects are commonly called Amplitude andPhase Ionospheric Scintillations.

Signal emitted by satellite

p

Severe amplitude fading and strong phasescintillation affect the reliability of GPSnavigational systems and satellitecommunications.

Scintillations at the receiver

The scintillations occur mainly at polar, auroral and equatorial

regions; more frequently aroundregions; more frequently around the solar maxima

Courtesy of Alfonsi

The perturbed high latitude ionosphereCourtesy of Un. of Bath

Experimental observations can improve our understanding of the cause-effect mechanisms producing negative effects p g g

on GPS signals

Courtesy of Un. of Bath

Synergic adoption of tomographic technique and scintillations measurements

De Franceschi et al., 2008

On the ICI-series of soundingOn the ICI-series of sounding rockets (2009-2014)

ICI-2 launch 10:35 UT 5 Dec 2008

Photo: Martin Langteigen

www.arcticscenes.com

The observational relationship between the optical cusp and HF radar cusp is well documented.cusp and HF radar cusp is well documented.

!! However, we are lacking verification on how HF backscatter irregularities form!!bac scatte egu a t es o

Spectral widths

≥220 ms-1

Moen et al., Ann. Geophysicae, 2000

O i i l S i Obj tiOriginal Science Objective: We want to test the potential role of gradient drift instability p g yto generate decameter scale HF backscatter targets.

Auroral boundary

NIMS

⎟⎠⎞

⎜⎝⎛⎟⎠

⎞⎜⎝

⎛ΔΔ

⎟⎟⎠

⎞⎜⎜⎝

⎛−=

BE

yn

n0

1γ 3-10 minGradient drift instability growth rate ⎠⎝⎠⎝ Δ⎠⎝ Byn0growth rate

Background I: Langmuir ProbeBackground I: Langmuir Probe

A typical I-V characteristic of a Langmuir probe.

(f )(from Lebreton et al., 2006)

OPERATIONAL MODES:OPERATIONAL MODES:

Swept probe : Advantage: Ni, Ne, Te at a time resolution of ~1s

Disadvantage: 7 km spatial resolution at 700 km altitudeDisadvantage: 7 km spatial resolution at 700 km altitude

Fixed Bias: Advantage: kHz sampling rate and high spatial resolution

Disadvantage: Ie is a function of (Ne, Te). Cannot make g e ( e, e)absolute density measurements by one probe

Background II: Langmuir Probe

2/kTλD b l th 20 / nekT eD ελ =Debye length:

λD in the ionosphere is of the order of cm r

If r ≥ λD Sheath effects are important. If r << λ Sheath effects can be neglectedIf r << λD Sheath effects can be neglected

Smaller the better! But we need to collect a sufficiently large current to measure!

m-NLP : Multi-Needle Langmuir Probe

2 or more cylindric probes: r = 0.25 mm, l = 25 mm

Advantages:

Shielding effects can be neglected

kHz sampling rates allow high spatial resolutionkHz sampling rates allow high spatial resolution

The need for Te can be eliminated

Elimination of TElimination of Te

VTKTANKI eeee += −121 1

( ) ( ) VKANKTANKI eeee += 212

12

( ) VKANKI ee Δ=Δ 22

12

VIKNe Δ

Δ=

2

32

Ve Δ3

We don’t even need to know the space craft potential!

VIKNe Δ

Δ=

2

32

VΔ

ESTEC Laboratory Test : It works!ESTEC Laboratory Test : It works!

INSTRUMENTATION on ICI-3

FBP Fi d Bi L i P b ISAS/JAXAFBP : Fixed Bias Langmuir Probe – ISAS/JAXA

m-NSLP : multi -Needle&Sphere Langmuir Probe system –University of OsloUniversity of Oslo

LEP-ESA : Low Energy Particle spectrometer (10eV-10keV), ISAS/JAXA

EFW : Electric Field and Wave Experiment, University of Oslo.

ADM : AC/DC Magnetometer - LPP. C/ C ag eto ete

SRADS: Sounding Rocket Attitude Detection System (UiO)

PMAFPMAF

HF1

HF2HF2

HF3HF3

HF1 HF2 HF3

KA

KA

KA

W W W

HF1

HF2

HF3

UNIVERSITYOF OSLO

Tentative schedule:• ICI 2 2008 Winter• ICI 3 2011 WinterICI 3 2011 Winter • ICI 4-5 2014 Winter (Solar Max?)• ICI 6-7 2016 Summer/EquinoxICI 6 7 2016 Summer/EquinoxAll rockets from Svalbard!

© Research Section for Plasma and Space Physics

EISCAT VALBARD RADAR : SP-NO-FASMReversed flow events: A new category of flow

channels opposing the large-scale background flow: First discovered by ESRAssociated with strong flow shears which may turn

upside down the way we think about ionosphericupside down the way we think about ionospheric instabilities

And generation of HF backscatter irregularities.

ICI 3 objectives:ICI-3 objectives:

Our main objective is to obtain a better physical description of instabilities and wave phenomena driven by the newly discovered Reversed Flow Events (RFEs) in the winter cusp ionosphere.T t h th th RFE i t d ith t ti l• Test whether the RFEs are associated with a tangential discontinuity (frozen into plasma) or a rotational discontinuity (indicative of reconnection)discontinuity (indicative of reconnection).

• Test whether the RFE-Birkeland current sheets are related to inverted Vs.

• Identification of wave phenomena and non-linear saturation.