I'll talk a bit about the telescope and my own visit, with a few photos, below the jump.
No-op: The case of Case and Deaton
14 hours ago
From: Dennis Ritchie
Newsgroups: comp.std.c Subject: Re: Computing sizeof() during compilation Organization: Bell Labs, Lucent Technologies > You are right. It was nice back in the days when things like > > #if (sizeof(int) == 8) > > actually worked (on some compilers). Must have been before my time. Dennis
Multimoment Radio Transient DetectionThis looks very promising, but there's some testing I wish they'd done. More on the subject below the jump.
Laura Spitler, Jim Cordes, Shami Chatterjee, Julia Stone
We present a multimoment technique for signal classification and apply it to the detection of fast radio transients in incoherently dedispersed data. Specifically, we define a spectral modulation index in terms of the fractional variation in intensity across a spectrum. A signal whose intensity is distributed evenly across the entire band has a much lower modulation index than a spectrum with the same intensity localized in a single channel. We are interested in broadband pulses and use the modulation index to excise narrowband radio frequency interference (RFI) by applying a modulation index threshold above which candidate events are removed. The technique is tested both with simulations and using data from sources of known radio pulses (RRAT J1928+15 and giant pulses from the Crab pulsar). We find that our technique is effective at eliminating not only narrowband RFI but also spurious signals from bright, real pulses that are dedispersed at incorrect dispersion measures. The method is generalized to coherent dedispersion, image cubes, and astrophysical narrowband signals that are steady in time. We suggest that the modulation index, along with other statistics using higher-order moments, should be incorporated into signal detection pipelines to characterize and classify signals.