Reanalysis TELECON Notes

Date: July 23, 2009 13:20 PDT

Attending:

Yuri,

Marianne

Mike

Geoff

Dmitri

Davin

Agenda:

1) Mike Visit and Inter-calibration

2) Report to Lab Fee Res. Program

Notes:

Intercalibration

1) SOPA

2) MCMP code

3) THEMIS

4) Assimilation by Yuri

5) Next meeting

Inter-calibration:

Mike is doing Inter calibration between LANL and other spacecrafts:

Currently we have AE8. AE9 is the next generation model for which interc-alibrated LANL data will be used.

Report by Tom Cayton on Instrument response function. Info used for spectral inferior, and is used for AE9 models.

Drift echos --> looks like a peak in the tail..

Higher energies, tend to have a difference

Calibration is free from time changes, and done for LANAL GEO and for GPS data.

1) SOPA - 2 element solid-state detector on LANL.

No magnets in the instrument. And each instrument is a little bit different. It has three telescopes that sweep out most of the unit sphere, and we can get directional info out of that.

How to differentiate electrons from protons:

Using the properties of the front and back detector:

- back detector is a thicker detector

- front is thinner

Electron channel tends to be cleaner than the proton, but depends on threshold steps.

Biggest problem in the 50keV lowest energy channel in the front detector, is that the dead layer will conduct a current causing thermally modulated noise.

Higher energies is quite reliable. Protons are not so predictable.

Task: Find the times for when data is not reliable.

During quiet times, ratio between min and max pitch angel is small, can thus use isotropy.

For all energies above 300 keV, fluxes measured are too high compared to LANL. Problem is about how to describe the discrepancy. Do a calibration, but trouble to explain why efficiency is greater than one.

Yuri: Could it be noise that is not shielded out. Answer: No, but will still look into it.

Higher fluxes for 100 keV electrons.

For GPS bremsstrahlung from MeV electrons can increase by a factor of 2. Hundreds of keV and up. Bremsstrahlung x-rays can come from any directions.

Calibration with GPS is done by Yue.

2) MCMP code: is a Monte Carlo code, used to be for bond simulation (public source). Similar to GEANT code (i.e. fully 3D reconstruction). Analytical approximation done by Michel Klesherskiy is a really good first step, 90% there. It is energy dependent.

GEO data pitch angle resolved up to 8.

3) THEMIS: apogee always over North America on the dawnward side.

Have LANL data available up to Jan 2008.

SST has an energy dependent response function. Inversion. Don’t have that information. will try to get that. need a good simulation with GEANT. Will be an energy dependent quality to it.

Dec 23rd: beginning of better SST data.

4) Yuri on assimilation:

Can start doing data assimilation look at similar things as done for CRRES data. Great for peaks in PSD and compare to previous results, relate to solar wind activity. Hopefully Mike will work on it, everyone will help.

Not planning to do pitch angle diffusion. A better way is to use the 3D code when that is ready. 3D with data assimilation. 3D code is working, but assimilation not included. Start doing that on third year.

Maybe look at parameter estimation, maybe easier when we have diff energy channels to constrain losses and energy diffusion.

Needs longer data period than a week. Depend on getting more on 1997/2008 data. Level 1 data given to them from Yuri.

Inter-calibration factor should stay the same and use it on the rest of the data.

Yuri might get THEMIS data on different L shells and good data coverage for the assimilation. Maybe a while to we have the same amount of data-set on THEMIS as we had from CRRES. Yuri will start with what he has. Maybe Mike can do it: See if the picture in general is the same as for CRRES, solar wind parameters? SW dependency meaning Yuri often see in CIR events, CME events, structure and peaks in psd, bigger slot region? Affect depletion? Not that strong depletion of RB, is all this related to SW parameters?

Yuri: Can we use other data for inter calibration?

SAMPEX?

5) Next meeting:

In two weeks.

Suggested agenda:

1) Mike can update us.

2) Think about future plans to do together.