Shaped Pupil Lyot Coronagraphs: High-Contrast Solutions for Restricted Focal Planes

Coronagraphs of the apodized pupil and shaped pupil varieties use the Fraunhofer diffraction properties of amplitude masks to create regions of high contrast in the vicinity of a target star. Here we present a hybrid coronagraph architecture in which a binary, hard-edged shaped pupil mask replaces the gray, smooth apodizer of the apodized pupil Lyot coronagraph (APLC). For any contrast and bandwidth goal in this configuration, as long as the prescribed region of contrast is restricted to a finite area in the image, a shaped pupil is the apodizer with the highest transmission. We relate the starlight cancellation mechanism to that of the conventional APLC. We introduce a new class of solutions in which the amplitude profile of the Lyot stop, instead of being fixed as a padded replica of the telescope aperture, is jointly optimized with the apodizer. Finally, we describe shaped pupil Lyot coronagraph (SPLC) designs for the baseline architecture of the Wide-Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets (WFIRST-AFTA) coronagraph. These SPLCs help to enable two scientific objectives of the WFIRST-AFTA mission: (1) broadband spectroscopy to characterize exoplanet atmospheres in reflected starlight and (2) debris disk imaging.Comment: 41 pages, 15 figures; published in the JATIS special section on WFIRST-AFTA coronagraph

Strategi Komunikasi Komunitas Saung Angklung Udjo dalam Mempopulerkan Budaya Lokal (Studi Kasus terhadap Budaya Lokal Musik di Indonesia)

Angklung merupakan identitas dan warisan Budaya Indonesia yang telah diakui oleh UNESCO sebagai karya agung Warisan Budaya. Era globalisasi sangat memerlukan strategi komunikasi yang tepat agar budaya angklung dapatdipopulerkan lebih kepada warga lokal dan mancanegara. Penelitian ini bertujuan untuk mengetahui bagaimana strategi komunitas Saung Angklung Udjo dalam mempopulerkan budaya lokal dengan penyampaian pesan melalui budaya lokal musik di Indonesia. Penelitian ini menggunakan metode penelitian kualitatif dengan teknik pengambilan data melalui wawancara mendalam dengan anggota komunitas Saung Angklung Udjo, observasi partisipatif, dan analisis konten dari media sosial yang digunakan. Data yang terkumpul dianalisis secara induktif melalui proses pengkodean dengan tema yang relevan. Hasil penelitian menunjukkan bahwa Angklung sempat kurang dukungan di tengah perkembangan budaya modern dan dominasi musik populer dari budaya barat. Namun melalui strategi komunikasi dalam komunitas oleh Machfoedz, angklung dapat dipopulerkan kepada khalayak yang lebih luas melalui dunia digital dan melalui berbagai kegiatan berdasarkan perspektif. Kesimpulan penelitian ini menunjukkan pentingnya penggunaan strategi komunikasi yang tepat dalam mendukung budaya alat musik tradisional di era digital, dalam konteks ini, komunitas angklung perlu memanfaatkan media sosial, situs web, platform digital lainnya untuk mempopulerkan budaya angklung, memberikan sajian informasi mengenai sejarah dan keunikan angklung dengan cara yang berbeda. Serta menekankan nilai kolaborasi dengan pihak lainnya dalam optimisme membentuk angklung sebagai masa depan Indonesia dalam membentuk sebuah identitas budaya yang lebih kuat

PENGARUH PEMAHAMAN DASAR MATEMATIKA TERHADAP HASIL BELAJAR PADA MATA PELAJARAN ESTIMASI BIAYA KONSTRUKSI KOMPETENSI KEAHLIAN DPIB DI SMK NEGERI 6 BANDUNG

Matematika dikenal sebagai ilmu dasar, yang mana dengan mempelajari matematika akan melatih keterampilan kritis, logis, analitis, dan sistematis. Namun, sampai saat ini matematika sendiri masih dianggap sulit oleh para siswa. Salah satu fenomena yang terjadi di lapangan yaitu masih ada siswa yang belum benar-benar paham mengenai rumus dan perhitungan dasar matematika yang digunakan untuk mata pelajaran Estimasi Biaya Konstruksi. Sehingga dilakukanlah penelitian ini untuk mengetahui pengaruh pemahaman dasar matematika terhadap hasil belajar mata pelajaran Estimasi Biaya Konstruksi. Penelitian ini bertujuan untuk mengetahui gambaran pemahaman dasar matematika, gambaran hasil belajar mata pelajaran Estimasi Biaya Konstruksi dan pengaruh pemahaman dasar matematika terhadap hasil belajar pada mata pelajaran Estimasi Biaya Konstruksi pada kompetensi keahlian Desain Pemodelan dan Informasi Bangunan (DPIB) di SMK Negeri 6 Bandung. Metode penelitian yang digunakan adalah metode penelitian deskriptif dan asosiatif dengan pendekatan kuantitatif. Jumlah sampel penelitian yaitu 98 responden dengan kriteria siswa DPIB kelas XI tahun ajaran 2021/2022. Instrumen yang digunakan yaitu tes pilihan ganda untuk mengukur pemahaman dasar matematika (variabel X) dan dokumentasi nilai tugas siswa untuk mengukur hasil belajar mata pelajaran Estimasi Biaya Konstruksi (variabel Y). Hasil penelitian berdasarkan analisis data menunjukkan bahwa gambaran pemahaman dasar matematika berada pada kategori sangat baik, gambaran hasil belajar mata pelajaran Estimasi Biaya Konstruksi berada pada kategori kompeten, dan pemahaman dasar matematika memiliki pengaruh positif dan signifikan terhadap hasil belajar mata pelajaran Estimasi Biaya Konstruksi. Kata Kunci: Hasil Belajar, Matematika, Estimasi Biaya Konstruksi. Mathematics is known as basic science, which studying mathematics will train critical, logical, analytical, and systematic skills. However, until now mathematics itself is still considered difficult by students. One of the phenomena that occur in the field is that there are still students who do not understand the basic mathematical formulas and calculations used for Construction Cost Estimation subjects. So, this research was conducted to determine the effect of a basic understanding of mathematics on the learning outcomes of Construction Cost Estimation subjects. This study aims to determine the description of the basic understanding of mathematics, the description of the learning outcomes of the Construction Cost Estimation subject, and the effect of the basic understanding of mathematics on learning outcomes in the Construction Cost Estimation subject on the competence of Building Modeling and Information Design (DPIB) skills at SMK Negeri 6 Bandung. The research method used is a descriptive and associative research methods with a quantitative approach. The number of research samples is 98 respondents with the criteria of DPIB class XI students for the 2021/2022 academic year. The instrument used is a multiple choice test to measure the basic understanding of mathematics (variable X) and documentation of student assignment scores to measure learning outcomes in the subject of Construction Cost Estimation (variable Y). The results of the study based on data analysis showed that the description of the basic understanding of mathematics was in the very good category, the description of the learning outcomes of the Construction Cost Estimation subject was in the competent category, and the basic understanding of mathematics had a positive and significant influence on the learning outcomes of the Construction Cost Estimation subject. Keywords: Learning Outcomes, Mathematics, Construction Cost Estimation

Numerically optimized coronagraph designs for the Habitable Exoplanet Imaging Mission (HabEx) concept

The primary science goal of the Habitable Exoplanet Imaging Mission (HabEx), one of four candidate flagship missions under investigation, is to image and spectrally characterize Earth-like exoplanets. It is well known that pupil obscurations degrade coronagraphic performance and complicate coronagraph design, so HabEx is planned to have an off-axis, unobscured primary mirror. We utilize the circular symmetry of the aperture to investigate 1D-radial coronagraph optimization methods that are prohibitively time-consuming or intractable in 2D, such as diffractive pupil remapping and concurrent, multi-plane optimization. We also directly constrain sensitivities to dynamic, low-order Zernike aberrations, which are separable in polar coordinates and can thus be propagated as 1D-radial integrals. The mask technologies in our designs claim heritage from the extensive modeling and testbed experiments performed by the Wide-Field Infrared Survey Telescope (WFIRST) Coronagraph Instrument (CGI) project. In this paper, we detail our optimization methods and outline future work to complete our design survey

Prospects for Exoplanet Imaging in Multi-Star Systems with Starshades

We explore the capabilities of a starshade mission to directly image multi-star systems. In addition to the diffracted and scattered light for the on-axis star, a multi-star system features additional starlight leakage from the off-axis star that must also be controlled. A basic option is for additional starshades to block the off- axis stars. An interesting option takes the form of hybrid operation of a starshade in conjunction with an internal starlight suppression. Two hybrid scenarios are considered. One such scenario includes the coronagraph instrument blocking the on-axis star, with the starshade blocking off-axis starlight. Another scenario uses the wavefront control system in the coronagraph instrument and using a recent Super-Nyquist Wavefront Control (SNWC) technique can remove the off-axis stars leakage to enable a region of high-contrast around the on-axis star blocked by the starshade. We present simulation results relevant for the WFIRST telescope

Experimental analysis of the achromatic performance of a vector vortex coronagraph

The vector vortex coronagraph is an instrument designed for direct detection and spectroscopy of exoplanets over a broad spectral range. Our team is working towards demonstrating contrast performance commensurate with imaging temperate, terrestrial planets orbiting solar-type stars using the High Contrast Imaging Testbed facility at NASA's Jet Propulsion Laboratory. To date, the best broadband performance achieved is ~10⁻⁸ raw contrast over a bandwidth of Δλ/λ=10% in the visible regime (central wavelengths of 550 nm-750 nm), while monochromatic tests yield much deeper contrast (~10⁻⁹ or better). In this study, we analyze the main performance limitations on the testbeds so far, focusing on the quality of the focal plane mask manufacturing. We measure the polarization properties of the masks and the residual electric field in the dark hole as a function of wavelength. Our results suggest that the current performance is limited by localized defects in the in the focal plane masks. A new generation of masks is under test that have fewer defects and promise performance improvements