A systematic approach to the Planck LFI end-to-end test and its application to the DPC Level 1 pipeline

The Level 1 of the Planck LFI Data Processing Centre (DPC) is devoted to the handling of the scientific and housekeeping telemetry. It is a critical component of the Planck ground segment which has to strictly commit to the project schedule to be ready for the launch and flight operations. In order to guarantee the quality necessary to achieve the objectives of the Planck mission, the design and development of the Level 1 software has followed the ESA Software Engineering Standards. A fundamental step in the software life cycle is the Verification and Validation of the software. The purpose of this work is to show an example of procedures, test development and analysis successfully applied to a key software project of an ESA mission. We present the end-to-end validation tests performed on the Level 1 of the LFI-DPC, by detailing the methods used and the results obtained. Different approaches have been used to test the scientific and housekeeping data processing. Scientific data processing has been tested by injecting signals with known properties directly into the acquisition electronics, in order to generate a test dataset of real telemetry data and reproduce as much as possible nominal conditions. For the HK telemetry processing, validation software have been developed to inject known parameter values into a set of real housekeeping packets and perform a comparison with the corresponding timelines generated by the Level 1. With the proposed validation and verification procedure, where the on-board and ground processing are viewed as a single pipeline, we demonstrated that the scientific and housekeeping processing of the Planck-LFI raw data is correct and meets the project requirements.Comment: 20 pages, 7 figures; this paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jins

VLBI for Gravity Probe B. V. Proper Motion and Parallax of the Guide Star, IM Pegasi

We present the principal astrometric results of the very-long-baseline interferometry (VLBI) program undertaken in support of the Gravity Probe B (GP-B) relativity mission. VLBI observations of the GP-B guide star, the RS CVn binary IM Pegasi (HR 8703), yielded positions at 35 epochs between 1997 and 2005. We discuss the statistical assumptions behind these results and our methods for estimating the systematic errors. We find the proper motion of IM Peg in an extragalactic reference frame closely related to the International Celestial Reference Frame 2 (ICRF2) to be -20.83 +- 0.03 +- 0.09 mas/yr in right ascension and -27.27 +- 0.03 +- 0.09 mas/yr in declination. For each component the first uncertainty is the statistical standard error and the second is the total standard error (SE) including plausible systematic errors. We also obtain a parallax of 10.37 +- 0.07 mas (distance: 96.4 +- 0.7 pc), for which there is no evidence of any significant contribution of systematic error. Our parameter estimates for the ~25-day-period orbital motion of the stellar radio emission have SEs corresponding to ~0.10 mas on the sky in each coordinate. The total SE of our estimate of IM Peg's proper motion is ~30% smaller than the accuracy goal set by the GP-B project before launch: 0.14 mas/yr for each coordinate of IM Peg's proper motion. Our results ensure that the uncertainty in IM Peg's proper motion makes only a very small contribution to the uncertainty of the GP-B relativity tests.Comment: Accepted for publication in the Astrophysical Journal Supplement Serie

Audio deformation based data augmentation for convolution neural network in vibration analysis

Audio deformations in audio processing have proved ability in preserve semantic meaning for audio signal. Convolution Neural Network (CNN) is among deep learning model that requires huge dataset during training for excellence performance Thus, data augmentation (DA) method is used to overcome the problem of limited dataset number for vibration analysis. Several signal processing phases including segmentation and image converting need to be performed before the vibration signal can be used as input for CNN. In this research, audio-deformation based DA is proposed in generating the additional vibration signal dataset. The proses is start by encoding the raw vibration signal to audio signal format to enable the audio deformation process performing, then decoding back into new vibration signal. Speed and amplify transformation are selected for audio deformation process. The new vibration data set of bearing fault detection problem are used for training CNN to validate the proposed approach. The results obtained from 13 experiments setting have shown that the proposed DA able to increase the accuracy of training for CNN until 13% compared with the previous DA method

Advanced InSAR atmospheric correction: MERIS/MODIS combination and stacked water vapour models

A major source of error for repeat-pass Interferometric Synthetic Aperture Radar (InSAR) is the phase delay in radio signal propagation through the atmosphere (especially the part due to tropospheric water vapour). Based on experience with the Global Positioning System (GPS)/Moderate Resolution Imaging Spectroradiometer (MODIS) integrated model and the Medium Resolution Imaging Spectrometer (MERIS) correction model, two new advanced InSAR water vapour correction models are demonstrated using both MERIS and MODIS data: (1) the MERIS/MODIS combination correction model (MMCC); and (2) the MERIS/MODIS stacked correction model (MMSC). The applications of both the MMCC and MMSC models to ENVISAT Advanced Synthetic Aperture Radar (ASAR) data over the Southern California Integrated GPS Network (SCIGN) region showed a significant reduction in water vapour effects on ASAR interferograms, with the root mean square (RMS) differences between GPS- and InSAR-derived range changes in the line-of-sight (LOS) direction decreasing from ,10mm before correction to ,5mm after correction, which is similar to the GPS/MODIS integrated and MERIS correction models. It is expected that these two advanced water vapour correction models can expand the application of MERIS and MODIS data for InSAR atmospheric correction. A simple but effective approach has been developed to destripe Terra MODIS images contaminated by radiometric calibration errors. Another two limiting factors on the MMCC and MMSC models have also been investigated in this paper: (1) the impact of the time difference between MODIS and SAR data; and (2) the frequency of cloud-free conditions at the global scale

Comparative study of different window sizes setting in median filter for off-angle iris recognition

Iris recognition is one of the most popular biometric recognition that has increased in the number of acceptance user gradually because of the reliability and accuracy provided by this system. However, this accuracy is highly correlated with the quality of iris image captured. Thus, a poor quality of the image captured required an enhancement technique. This study aims to identify the optimum window size for the median filter. Identifying the optimum window size setting required template matching value result of the off-angle iris recognition. The lowest value obtained showed that the window size applied was optimized. The result of this study demonstrated, for WVU-OA dataset for 15 degrees off-angle iris of right and left eyes, the window size of [5 5] and [7 7] respectively are optimum to maximize the median filter function. Meanwhile, for 30 degrees off-angle iris of right and left eyes data, the optimum windows size proposed are [7 7] and [5 5] respectively. On the other hand, analysis using UBIRIS dataset showed that the optimum window size for 30 degrees off-angle iris, both right and left eye is [7 7] which is able to maximize the performance of the median filter. In conclusion, the effective value to be applied to all dataset are [5 5] and [7 7] because in most cases it provides a better template matching compared to without applying the filtering method

VLBI for Gravity Probe B. VII. The Evolution of the Radio Structure of IM Pegasi

We present measurements of the total radio flux density as well as very-long-baseline interferometry (VLBI) images of the star, IM Pegasi, which was used as the guide star for the NASA/Stanford relativity mission Gravity Probe B. We obtained flux densities and images from 35 sessions of observations at 8.4 GHz (wavelength = 3.6 cm) between 1997 January and 2005 July. The observations were accurately phase-referenced to several extragalactic reference sources, and we present the images in a star-centered frame, aligned by the position of the star as derived from our fits to its orbital motion, parallax, and proper motion. Both the flux density and the morphology of IM Peg are variable. For most sessions, the emission region has a single-peaked structure, but 25% of the time, we observed a two-peaked (and on one occasion perhaps a three-peaked) structure. On average, the emission region is elongated by 1.4 +- 0.4 mas (FWHM), with the average direction of elongation being close to that of the sky projection of the orbit normal. The average length of the emission region is approximately equal to the diameter of the primary star. No significant correlation with the orbital phase is found for either the flux density or the direction of elongation, and no preference for any particular longitude on the star is shown by the emission region.Comment: Accepted for publication in the Astrophysical Journal Supplement Serie

Disentangling the Taxonomy of the Mahseers (Tor spp.) of Malaysia: An Integrated Approach Using Morphology, Genetics and Historical Records

The establishment of appropriate taxonomic designations is essential for the effective management of fishery resources. Despite over a century of explorations and research, the cyprinid genus Tor represents a group of large-bodied freshwater fishes whose taxonomy and systematics remains poorly known. While five species of Tor are currently listed as “endangered” on the IUCN Red List, a further five out of 18 species currently recognized are assessed as “data deficient,” with at least one undescribed species, believed to be on the brink of extinction (i.e., the Humpback Mahseer endemic to the Cauvery River in India). Tor mahseers represent a suitable model for the application of an integrated approach using morphology, genetics, and historical records to resolve species identities, where one or more of these fundamental approaches may have been deficient in the past. Focusing specifically on the taxonomy and nomenclature of the Tor species recorded from Peninsular Malaysia, one of the aims of this review is to define the identity of two nominal species, T. tambra and T. tambroides. Original descriptions of these two nominal species contain little or practically no characters to distinguish them, and partly explains why secondary literature fails to conclusively determine species boundaries. A phylogenetic analysis of mahseer specimens from this region, based on publicly available and newly sequenced mitochondrial COX1 genes, does not support species designation based on previously established morphological features. More importantly, multiple tree-based species delimitation approaches showed that previously sequenced T. tambroides from Peninsular Malaysia and the newly described Tor species from Vietnam could not be delimited from the topotypic Tor tambra. A wider investigation of mahseer taxonomy covering all of Southeast Asia, using such an integrated approach is recommended to resolve the ambiguous taxonomy and is of profound importance for the conservation and management of exploited and farmed populations of these highly valued and iconic fish

Gamma-Ray Burst Sequences in Hardness Ratio-Peak Energy Plane

The narrowness of the distribution of the peak energy of $\nu F_{\nu}$ spectrum of gamma-ray bursts (GRBs) and the unification of GRB population are great puzzles yet to be solved. We investigate the two puzzles based on the global spectral behaviors of different GRB population in the $HR-E_{\rm{p}}$ plane (HR the spectral hardness ratio) with BATSE and HETE-2 observations. It is found that long GRBs and XRFs observed by HETE-2 seem to follow the same sequence in the $HR-E_{\rm{p}}$ plane, with the XRFs at the low end of this sequence. The long and short GRBs observed by BATSE follow significantly different sequences in the $HR-E_{\rm p}$ plane, with most of the short GRBs having a larger hardness ratio than the long GRBs at a given $E_{\rm{p}}$. These results indicate that the global spectral behaviors of the long GRB sample and the XRF sample are similar, while that of short GRBs is different. The short GRBs seem to be a unique subclass of GRBs, and they are not the higher energy extension of the long GRBs (abridged).Comment: 9 pages, 3 figure

Implantable slot antenna with substrate integrated waveguide for biomedical applications

This work presents a new design of capsule slot antenna with substrate integrated waveguide (SIW) for wireless body area networks (WBANs) operating at the range of (2.5-4 GHz) which is located in the body area networks (BAN) standard in IEEE802.15.6. The proposed antenna was designed for WBANs. The substrate is assumed to be from Rogers 5880 with relative permittivity of 2.2, and thickness of 0.787 mm. The ground and the patch are created from annealed copper while the capsule is assumed to be a plastic material of medical grade polycarbonate. The antenna designed and summited using computer simulation technology (CST) software. A CST voxel model was used to study the performance of SIW capsule antenna and the ability of the band (2.5-4 GHz). Results indicated a wide bandwidth of 1.5 GHz between the range of (2.5-4) GHz at 3.3 GHz as center frequency, with return loss with more than -24.52 dB, a gain of -18.2 dB, voltage standing wave ratio (VSWR) of 1.17, and front-to-back ratio (FBR) of 10.07 dB. Through simulation, all considerable parameters associated with the proposed antenna including return loss, bandwidth, operating frequency, VSWR less than 2, radiation pattern were examined. Regarding size, gain, and frequency band, the proposed antenna is located with the standards of implantable medical devices

Dual circular-polarized slot antenna design for wireless mimo system at 2.4 ghz

This work proposed a dual circular-polarized slot antenna for wireless local area network (WLAN) application at 2.4 GHz. The proposed design is simulated by using FR-4 as is substrates. In this work, three stages of antenna had been simulated in CST Microwave Studio. First two antenna, Design 1-A and Design 1-B is containing a single polarized antenna with different feedline port location. An X-shaped structure is located at the middle of the patch at angle of 42.5 degrees. Then, dual feedline port antenna, Design B1 are designed to create dual circular-polarized effect. The return loss S11 results at 2.4 GHz of Design 2-A antenna are-21.511 dB and-28.48 dB for simulation results and measurement results, respectively. For axial ratio for Port 1 and Port 2 are 0.63 and 1.12, respectively. In the end, the simulation and measured antenna design are compared