- ...detail.
- Although
the term SuperDARN is usually used to describe the whole network
of radars, it is used in this thesis as acronym for the
Saskatoon and Kapuskasing radar pair.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...height.
- There exists also a D-region (or D-layer)
located at around 50-90 km.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...parameters.
- Solar wind plasma parameters at 1AU
are 25#25, 26#26 which gives
an approximate collision frequency of 27#27 and a conductivity
estimate of 28#28. The resulting time for a scale size
of 29#29 is about 30#30 or about 20 days.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...Bur88].
-
A recent example that highlights the importance of solar-wind monitoring,
was the Wind-Geotail Magnetic Cloud Event,
October 18-20, 1995. Here is an excerpt from L. F. Burlaga's WWW-text dated
Nov. 3, 1995:
A magnetic cloud
arrived at the WIND satellite approximately 19 UT on Oct. 18, 1995. The
magnetic field direction was observed to turn southward abruptly when WIND
entered the magnetic cloud, and the magnetic field rotated gradually to a
northward orientation over the course of about 30 hours as the cloud moved
past the spacecraft. The magnetic field was strong inside the cloud, and its
magnetic signature that of an approximately force-free field with a flux
rope geometry. A corotating field was overtaking the magnetic cloud and
interacting with it, intensifying the northward magnetic fields in the rear
of the cloud. The prolonged interval of negative 37#37 is expected
to produce geomagnetic disturbances, particle precipitation, aurorae,
enhanced cross-cap potentials and other effects. The subsequent prolonged
interval of positive 37#37 should be associated with a return of the
magnetosphere to a quiet state. The slow, systematic variation in the
magnetic field direction during passage of the magnetic cloud past earth is
expected to produce systematic changes in the ionospheric convection pattern
and possibly observable variations in the high altitude winds.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...equations.
- An optimized set of equations
that can be used for this purpose has been described by Haselgrove
[Has63].
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...drift).
- Here we used the gyrofrequency 65#65
of a charged particle in a magnetic field B given by 116#116, where e ist the charge and m the mass of the particle. We
also used the collision frequency 64#64 of the particle in the medium. The
subscripts denote the species under consideration, i.e. `e' for electrons
and `i' for ions. The conductivity types refered to as `Pedersen'
and `Hall' are currents flowing respectively parallel and perpendicular to
the electric field. They have an associated drift with the same name.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...wave.
- Note that the antenna gain used in the derivation is not
defined in a coordinate system centered at the transmitter and is not a
power gain.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...instruments.
- The Saskatoon/Kapuskasing pair in particular will make use of: the
SAPPHIRE Saskatoon radar operated by the University of Saskatchewan, ISAS; the CANOPUS
network; all-sky auroral imagers in Rabbit Lake, Sask.,
Eureka, NWT and Rankin Inlet, NWT; satellites such as the DMSP series, WIND,
IMP-8, etc.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...considered
- That is, the first pulse is transmitted at time t=0 and the
second pulse is transmitted at time 217#217.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...sampling
- For normal SuperDARN
operation there are about 54 missing out of 1190 possible ACF points,
i.e. about 4.5%, due to this multi-pulse transmission related interference.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...T.
- The
maximum lag time is 248#248.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...sequences.
- The number of sequences are 250#250.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...value
- From a pulse-sequence with 247#247 pulses one can
obtain 253#253 lag separations that are
different from 0.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...high
- The author has recently developed a program implementing the
brute-force algorithm using table-lookup techniques that is equivalent in
speed to fitting methods.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...(CADI)
- These values are not
absolute since CADI measurements are themselves subject to error.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...times
- A good discussion about orbits and stabilization can be found in
Wertz [Wer78] Chapters 3.4 and 12.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...energy
- Additional information about the DMSP satellite program and the
sensors, including sample spectrograms, are available on the Internet at
the URL http://web.ngdc.noaa.gov/dmsp/dmsp.html
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...used.
- Documentation and program code for MSIS86
model can be obtained at the URL
ftp://nssdc.gsfc.nasa.gov/pub/models/msis86.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...satellite
- Time = Universal Time (UT), DoY = days of year,
SoD = seconds of day
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...assumed.
- In
contrast, for a Maxwellian energy distribution the average energy is twice
the characteristic energy.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...spectra
- A comparison, recently done
by the author, of a small
sample of data between the velocities derived from the SuperDARN phase-fit
technique and the velocities derived by inspection of the corresponding
spectra comes to the same conclusion.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.