URSI General Assembly, Istanbul, Turkey, August 2011
URSI Commission J
- Good intro, and reasoning as to why to do this
- Calibration is a fairly hard thing, due to the ionosphere
- RFI problems for SKA-low ( Big surprise!)
- Maybe meteor scatter, Whistlers, anomalous propagation
- J01.4 AEE Rogers -
- Hot noise source, custom made.
- Can't rely on the "smoothness" of a 2-1 bandwidth antenna
- Lower frequency observing is more sensitive to magnetic fields and distortions, hence the ionospheric problems...
- Luminous quasar in EOR space.
- JF??? Aron Parsons EOR lecture
- EVLA 74 and 330 MHz feeds
- J04.2 Space-based ULW Radio Astronomy
- J04.3 Radio Astron talk
- Receiving proposals for ground telescopes and tracking stations
- Mentioned GB by name along with NZ and SA as possible tracking stations
- J04.5 China VLBI talk
- Satellite tracking and orbit determination with VLBI. Moon mission, possible mars mission, etc.
- VLBI for orbit determination for solar sail satellite due to constant large forces (acceleration) due to the sail
- Wideband digital downconverter for recovering the clock tone
- Argumentation chain about whether to keep the data or not.
- Disks are degenerating into serial devices since access speed isn't keeping up with capacity growth
- Very good talk on justification for pipelines
- Direction dependent effects
- Beamshape variations
- Meq trees
- J06.6 Shapelets
- landow-pollok theorem
- Prolete Spheroidal bessel functions
- IEEE ISSPIT
- Useful talk about using apriori information to look for signals and for cleaning images
- Use spherical instead of planar imaging.
- Supposedly works better, due to the data shape being spheroidal to start with.
- Interference cancellation
- Ronnie Levenda
- Rotating field, due to earth's rotation. causes interference to appear differently in different beams
- Mutual coupling terms important, modified beamshapes of each element
URSI General Lecture
- SMOS Passive Phased Array
URSI Commission E
- E01.5 SE testing of small enclosures
- Beware of near-field effect of small enclosure
- Used spherical dipole with electronics inside it
- Eliminates cables to the antenna which may affect readings
- Scale results using the voltage needed to drive the antenna
- SE = [TRPen/Ven] / TRPfs/Vfs ]
- Should define SE in terms of transfer impedance, not loss.
URSI Commission ??
- Analog Photonic A-D
- See Walden Plot (R. Walden)
- R. Williamson (2003)
- S. Gupta (2008)
- 7.0 ENOB at 41 GHz
- A Khilo
- M.e. Grein (2011)
- Limited by M-Z non-linearities
- DARPA W911NF-04-1-0431
- NSF 0645960
URSI Commission A
- Up to 70% of cost of devices is in passives.
- so use embedded passives.
- Just test of permittivity using VNA and matallizing the sample, or compressing it in a fixture
- Use coaxial probe if material is > 1 CM thick
- use resonant cavity
- Use transmission line (waveguide)
- Use free space.
- Sample size must be greater than 10 lambda
URSI Commission J business meetings
- 19 people in Comm J died in the past 3 years
- talked about vice-chair for next 3 yrs
- Got vote done, Rich Bradley didn't win
Lorimer Bursts: whistlers, meteors, terrestrial?
Gnu radio for demodulator for RA project?