#### DMCA

## RESEARCH IN RADIO FREQUENCY INTERFERENCE MITIGATION (2005)

### Citations

70 |
Interferometry and Synthesis in Radio Astronomy.
- Thompson, Moran, et al.
- 1986
(Show Context)
Citation Context ...n will describe the basic building block of a synthesis array: the interferometer. This will be a brief discussion. More detailed treatments of an interferometer can be found in [14], [11], [12], and =-=[16]-=-. Each pair of antennas in an imaging array makes up an interferometer. Figure 2.6 shows the basic structure of an interferometer. An incoming plane wave is depicted as a dashed line. The plane wave r... |

43 | Multichannel interference mitigation techniques in radio astronomy
- Leshem, Veen, et al.
- 2000
(Show Context)
Citation Context ....2 is a review of subspace projection and its use in synthesis imaging RFI mitigation. Subspace methods are familiar territory in signal processing and the reader is advised to consult [9], [29], and =-=[30]-=- for more detail. Section 6.3 describes the CSP algorithm. Section 6.4 describes an RFI scenario and a simulation using the CSP algorithm. 6.2 Subspace Projection Subspace projection algorithms are ba... |

18 | Auxiliary antenna assisted interference mitigation for radio astronomy arrays - Jeffs, Li, et al. - 2005 |

11 | Spatial filtering of RF interference in radio astronomy
- Raza, Boonstra, et al.
- 2002
(Show Context)
Citation Context ... Section 6.2 is a review of subspace projection and its use in synthesis imaging RFI mitigation. Subspace methods are familiar territory in signal processing and the reader is advised to consult [9], =-=[29]-=-, and [30] for more detail. Section 6.3 describes the CSP algorithm. Section 6.4 describes an RFI scenario and a simulation using the CSP algorithm. 6.2 Subspace Projection Subspace projection algorit... |

9 | Interference mitigation using a focal plane array
- Hansen, Warnick, et al.
- 2005
(Show Context)
Citation Context ...s therefore: 290(100.15 − 1) = 120 Kelvin. The antennas for the VSA are 3-meter (diameter) dishes with an antenna efficiency of 50%. This is a typical efficiency figure for these types of dishes (see =-=[26]-=-). Using Equation 4.5, Cassiopeia A will produce 1.92 Kelvin of temperature in the antennas of the VSA. This corresponds to about -18 dB SNR. Radio astronomers deal with noise by integrating (averagin... |

8 |
Deconvolution. In Synthesis Imaging in Radio Astronomy: Third NRAO Summer School,
- Cornwell
- 1989
(Show Context)
Citation Context ...ynthesized beam and lower its sidelobes [20]. They will also process a synthesized image using a process called deconvolution in a further effort to overcome the undesirable effects of the dirty beam =-=[23]-=-. Examining the dirty beam, in particular the main lobe of the dirty beam, also provides an estimate of the resolution of the array. Here, resolution means how close two point sources can be before th... |

6 |
Imaging,” in Synthesis Imaging in Radio Astronomy
- Sramek, Schwab
- 1989
(Show Context)
Citation Context ... only know at a discrete number of points (as shown in Figures 2.11 and 2.12). This discrete sampling of the uv plane can be understood in terms of Fourier theory. The treatment below follows that of =-=[20]-=- (see also [11]). The sampled visibilities V Sν (u, v) are equal to the continuous value of Vν(u, v) multiplied by a sampling function composed of a spatial distribution of deltas: V Sν (u, v) = S(u, ... |

6 |
Willsky with
- Oppenheim, S
- 1997
(Show Context)
Citation Context ...with noise by integrating (averaging) over time. Each time sample can be treated as an independent and identically distributed random variable. For a sampled bandwidth B, the Nyquist sampling theorem =-=[27]-=- requires that the sample rate be twice the sampled bandwidth. If the integration occurs for a time tint, then the number of independent samples that are integrated is Ns = 2Btint. The standard deviat... |

5 |
Time blanking for gbt data with radar rfi
- Dong
- 2004
(Show Context)
Citation Context ... data, adaptive beam forming, and spatial filtering by subspace projection methods. Our research here at Brigham Young University is directed toward developing and testing RFI mitigation methods (see =-=[7]-=-, [8], and [9]). The array described by this thesis will allow us to test our mitigation algorithms using real data. 2 1.3 Thesis Contributions The primary contribution of this thesis is development o... |

5 | Real-time Adaptive Cancellation of Satellite Interference
- Poulsen
- 2003
(Show Context)
Citation Context ..., adaptive beam forming, and spatial filtering by subspace projection methods. Our research here at Brigham Young University is directed toward developing and testing RFI mitigation methods (see [7], =-=[8]-=-, and [9]). The array described by this thesis will allow us to test our mitigation algorithms using real data. 2 1.3 Thesis Contributions The primary contribution of this thesis is development of a w... |

5 |
Beamforming techniques and interference mitigation using a multiple feed array for radio astronomy
- Hansen
- 2004
(Show Context)
Citation Context ... dishes. This small array has been used to test RFI mitigation algorithms. For more detail the reader is referred to the Master’s theses of Brett Walkenhorst [21], Andrew Poulsen [8], and Chad Hansen =-=[22]-=-. 27 Figure 3.1: Block diagram test platform concept. The low noise amplifiers for the array were chosen based on the advice of our collaborators at NRAO. The LNAs for the VSA are made by Mini-Circuit... |

4 |
Fundamentals of radio interferometry,” in Synthesis Imaging in Radio Astronomy
- Thompson
- 1999
(Show Context)
Citation Context ...e observing frequency ν, and u, v, and w are the vector components of b measured in wavelengths. The w axis points toward the celestial north pole, and the uv plane is parallel to the earth’s equator =-=[14]-=-. In Equation 2.13, l, m, and n are the direction cosines of s for the angles from the u, v, and w axes respectively, as shown in Figure 2.4 (see [15]). This leads to the following form for Vν : Vν(u,... |

4 |
Development of a Radio Telescope Receiver for Research
- Walkenhorst
- 2001
(Show Context)
Citation Context ...ray consisting of three of the three meter dishes. This small array has been used to test RFI mitigation algorithms. For more detail the reader is referred to the Master’s theses of Brett Walkenhorst =-=[21]-=-, Andrew Poulsen [8], and Chad Hansen [22]. 27 Figure 3.1: Block diagram test platform concept. The low noise amplifiers for the array were chosen based on the advice of our collaborators at NRAO. The... |

3 |
Electromagnetic Wave Theory. Chapter 3
- Kong
- 1986
(Show Context)
Citation Context .... (2.8) Lastly, the element solid angle is given by dS = |R|2dΩ. (2.9) In simplifying Equation 2.6, the following two approximations are used: the far-field approximation: |R − r| ≈ |R| − r·R|R| (see =-=[13]-=-), and |R − r2| − |R − r1| ≈ |r1 − r2| when |R| >> |r1|, |r2|. This produces Vν(r1, r2) = ∫ I(s)e−j2piνs·(r1−r2)/cdΩ. (2.10) This resembles a Fourier transform. Notice that Vν(r1, r2) is a function of... |

3 |
Sensitivity”, in Synthesis Imaging in Radio Astronomy
- Wrobel, Walker
- 1999
(Show Context)
Citation Context ...thematical model for this section, a brief review is presented of noise in radio astronomy observations. Noise and its effects in radio astronomy synthesis imaging are covered by Walker and Wrobel in =-=[24]-=-. 4.3.1 Noise in Radio Astronomy Astronomers describe system noise power, and power from astronomical sources, in terms of an equivalent noise temperature using the Rayleigh-Jeans approximation (for m... |

2 |
Coherence in radio astronomy,” in Synthesis Imaging in Radio Astronomy
- Clark
- 1999
(Show Context)
Citation Context ...esis in radio astronomy, the uv plane, interferometry, and Fourier transform imaging. 2.1 Synthesis Imaging Formulation The treatment of synthesis imaging presented here closely follows that of Clark =-=[10]-=-. Extra detail will be presented for the benefit of those who will continue to work on the project. Clark formulates synthesis imaging by deriving the form of the observed electric field, from which h... |

2 |
Fundamentals of interferometry
- Perley
- 2004
(Show Context)
Citation Context ...r1| e−j2piν|R−r2|/c |R− r2| dS. (2.6) 2.1.7 Observed Intensity We will recast Equation 2.6 in order to simplify it and introduce the names used by astronomers for quantities in Equation 2.6 (see [11] =-=[12]-=-). The unit vector s is defined as s = R |R| . (2.7) Observed intensity is defined as Iν = |R|2〈|Eν(s)|2〉. (2.8) Lastly, the element solid angle is given by dS = |R|2dΩ. (2.9) In simplifying Equation ... |

2 |
Calibration and editing,” in Synthesis Imaging in Radio Astronomy
- Fomalont, Perley
- 1999
(Show Context)
Citation Context ...ment, and the most crucial. For example, the measured phase between elements of the VLA is calibrated to have “phase stability of better than one degree of phase per gigahertz of observing frequency” =-=[28]-=-. The remainder of this section is devoted to describing simulations performed to examine the effects of phase error and quantify the amount of tolerable phase error. The source model for these simula... |

1 |
time parcels”, World Wide Web, See Appendix E for the full url
- “Real
(Show Context)
Citation Context ...3 Dirty beam for the uv coverage in Figure 2.11. . . . . . . . . . . . . . 25 3.1 Block diagram test platform concept. . . . . . . . . . . . . . . . . . . 28 3.2 Satellite photo of the Clyde Building =-=[1]-=-. . . . . . . . . . . . . . . . . 29 3.3 Clyde Building roof layout [2]. . . . . . . . . . . . . . . . . . . . . . . 30 3.4 A view of the eastern sky at 35 ft away from the fifth floor. . . . . . . 32... |

1 |
Basics of interferometry”, http://www.atnf.csiro.au/whats on/workshops/synthesis2003/talks/basics.pdf
- McConnell
- 2003
(Show Context)
Citation Context ... |R− r1| e−j2piν|R−r2|/c |R− r2| dS. (2.6) 2.1.7 Observed Intensity We will recast Equation 2.6 in order to simplify it and introduce the names used by astronomers for quantities in Equation 2.6 (see =-=[11]-=- [12]). The unit vector s is defined as s = R |R| . (2.7) Observed intensity is defined as Iν = |R|2〈|Eν(s)|2〉. (2.8) Lastly, the element solid angle is given by dS = |R|2dΩ. (2.9) In simplifying Equa... |

1 | and Hille’s Calculus: One and Several Variables, chapter 12 - Salas, Salas - 1995 |

1 |
Positional astronomy - index”, http://star-www.st-and.ac.uk/∼fv/webnotes/index.html
- Vincent
- 2003
(Show Context)
Citation Context ...for the measured visibility Vν(u, v). In what follows it is assumed that the reader has some familiarity with astronomical coordinate systems. A good introductory reference on positional astronomy is =-=[17]-=-. The convention found in astronomical literature has been used to specify locations on the celestial sphere. δ0 is the symbol that is used for declination, which is 17 Figure 2.8: A baseline projecte... |

1 |
Radio astronomy lecture #6
- Gary
- 2004
(Show Context)
Citation Context ...ligned with earth’s rotation axis, with the z axis pointed at the celestial north pole: δ0 = 90 ◦, the x axis is pointed at H0 = −6h, δ0 = 0◦, and the y axis is pointed at H0 = 0h, δ0 = 0 ◦ [14] [16] =-=[18]-=-. 18 To determine the locations of the antennas in this coordinate system we perform the following coordinate rotation: x y z = 0 − sin γ cos γ 1 0 0 0 cos γ sin γ e... |

1 | Microwave Engineering, chapter 10 - Pozar - 1998 |

1 |
Digital Singal Processing Implementation using the TMS320C6000 DSP Platform
- Dahnoun
- 2000
(Show Context)
Citation Context ....4.1 Introduction To begin understanding the C6000 family Processor, you should read the following chapters and sections of Digital Signal Processing Implementation using the TMS320C6000 DSP Platform =-=[32]-=-: 1, 2, 3.1, 3.2, 4, 8.5, and 8.6. Chapter 2 is especially helpful because it introduces the processor’s architecture. In particular, the chapter introduces the CPU, memory, and interrupt structure of... |