SSTRED: Data- and metadata-processing pipeline for CHROMIS and CRISP

Context. Data from ground-based, high-resolution solar telescopes can only be used for science with calibrations and processing, which requires detailed knowledge about the instrumentation. Space-based solar telescopes provide science-ready data, which are easier to work with for researchers whose expertise is in the interpretation of data. Recently, data-processing pipelines for ground-based instruments have been constructed. Aims. We aim to provide observers with a user-friendly data pipeline for data from the Swedish 1-meter Solar Telescope (SST) that delivers science-ready data together with the metadata needed for proper interpretation and archiving. Methods. We briefly describe the CHROMospheric Imaging Spectrometer (CHROMIS) instrument, including its (pre)filters, as well as recent upgrades to the CRisp Imaging SpectroPolarimeter (CRISP) prefilters and polarization optics. We summarize the processing steps from raw data to science-ready data cubes in FITS files. We report calibrations and compensations for data imperfections in detail. Misalignment of Ca II data due to wavelength-dependent dispersion is identified, characterized, and compensated for. We describe intensity calibrations that remove or reduce the effects of filter transmission profiles as well as solar elevation changes. We present REDUX, a new version of the MOMFBD image restoration code, with multiple enhancements and new features. It uses projective transforms for the registration of multiple detectors. We describe how image restoration is used with CRISP and CHROMIS data. The science-ready output is delivered in FITS files, with metadata compliant with the SOLARNET recommendations. Data cube coordinates are specified within the World Coordinate System (WCS). Cavity errors are specified as distortions of the WCS wavelength coordinate with an extension of existing WCS notation. We establish notation for specifying the reference system for Stokes vectors with reference to WCS coordinate directions. The CRIsp SPectral EXplorer (CRISPEX) data-cube browser has been extended to accept SSTRED output and to take advantage of the SOLARNET metadata. Results. SSTRED is a mature data-processing pipeline for imaging instruments, developed and used for the SST/CHROMIS imaging spectrometer and the SST/CRISP spectropolarimeter. SSTRED delivers well-characterized, science-ready, archival-quality FITS files with well-defined metadata. The SSTRED code, as well as REDUX and CRISPEX, is freely available through git repositories.

Bringing an Historic Collection into the Modern Era: Curating the J. K. Underwood Seed Collection at the University of Tennessee Herbarium (TENN)

The University of Tennessee Herbarium (TENN) presents a case study for modernizing an historic seed collection. TENN staff recently rediscovered the J. K. Underwood Seed Collection (ca. 1931–1964), containing over 700 unique specimens, hidden away in storage. We employed a series of curation actions to modernize the collection and render it useful to researchers. This included physically organizing and digitally indexing the collection, updating scientific names to current taxonomy, storing the specimens in modern archival-quality containers, housing the collection in environmentally-controlled conditions, and increasing accessibility of the collection by photographing specimens and integrating these images into our existing website (tenn.bio.utk.edu). Our efforts also included developing a protocol for adding new accessions to the collection and advertising the utility of the collection as a source of morphological data on seeds for identification, research, and teaching. We also review modern strategies for curating seed collections. Specifically, we emphasize the importance of increasing visibility of collections through visual, digital representations. This expands the utility of collections and fosters global information sharing across disciplines. We present our curation project as a case study that can serve as a model for curating historic seed collections.

Little-known Dangers to Natural History Collections: Bynesian Decay and Pyrite Decay

The deterioration of specimens in natural history collections is a major concern of curators. Collections containing carbonatic specimens (e.g., molluscs, corals, fossils) are of special concern, since calcium carbonate (CaCO3) can deteriorate in the presence of acidic vapours. There are two main types of danger related to these volatile acids, called Bynesian decay and pyrite decay. In Bynesian decay, acetic and formic acids are released by storage materials (e.g., wood, varnishes, cardboard). If the collection is not under adequate conditions and presents high relative humidity and temperature, the acids react with the specimens’ carbonate, yielding salts and carbon dioxide. The tell-tale “symptom” of an affected specimen is a thin white granular layer of efflorescing salts. Pyrite decay is somewhat similar, but restricted to fossils that contain the mineral pyrite (FeS2). In high relative humidity, pyrite is oxidised, yielding sulfuric acid, which can in turn corrode carbonatic specimens lodged in the same drawer or cabinet. The corrosion damage caused is irreversible, of course, but the affected specimens might be partially salvaged via specific cleaning and treating procedures. Nevertheless, it is better to just avoid the problem altogether by keeping the collection facilities in adequate conditions. It is hard to come up with a single solution for all the problems any given collection might face, but some measures are reasonably universal. First and foremost, one should strive to maintain a low relative humidity (45–50%) and an appropriate temperature range (16–21ºC). This can be achieved, for instance, with HVAC systems and the use of common desiccant materials such as silica gel. Conditions within the collection should be monitored via the combined use of hygrometer, thermometer, and pH indicators. Furthermore, archival quality materials should be used as often as possible, such as steel drawers and cabinets with electrostatic coating, and acid-free paper and cardboard. Finally, specimens containing reactive pyrite must be kept isolated in archival quality plastic (e.g., mylar) or glass containers.

James Galanos, Silk Chiffon Afternoon Dress c. Fall 1976

The URL links to a website page in the Drexel Digital Museum (DDM) fashion image archive containing a 3D interactive panorama of an evening suit by American fashion designer James Galanos with related text. This afternoon dress is from Galanos' Fall 1976 collection. It is made from pale pink silk chiffon and finished with hand stitching on the hems and edges of this dress, The dress was gifted to Drexel University as part of The James G. Galanos Archive at Drexel University in 2016. After it was imaged the gown was deemed too fragile to exhibit. By imaging it using high resolution GigaPan technology we are able to create an archival quality digital record of the dress and exhibit it virtually at life size in 3D panorama. The panorama is an HTML5 formatted version of an ultra-high resolution ObjectVR created from stitched tiles captured with GigaPan technology. It is representative the ongoing research of the DDM, an international, interdisciplinary group of researchers focused on production, conservation and dissemination of new media for exhibition of historic fashion.

Scotland

I spent 14 days of intensive photographic research taking 10 000 photographs while travelling around the coast of Scotland. This includes the incredible architecture in ancient cities; amazing, magical landscapes of heather shrouded moorlands, expansive glens with grass covered hills and lowlands, and black and red mountains; and magnificent castles. Scotland is a part of my cultural heritage. This series of photographs is a merging of my artistic and academic skills as a visual arts researcher. It is similar to grounded theory (Glaser & Strauss, 1967) used for my academic research wherein I let Scotland tell me what photographs needed to be taken and my photographic eye knew when to take the photograph from my years of experience as a photographer. Each of the photographs tells a visual story. As I continuously edited my photographs for months while making files in folders I asked myself: What was my experience of Scotland? How can I represent this experience so that it has the feeling of what each inspiring photograph had when I took the shot? It is a reliving and recreating of experience while working with specialty silver papers and creating triptychs, diptychs and other layouts to photographically tell the stories. These 19-limited edition colour archival quality giclée photographic prints are the result of my photographic Scotland experience. An exhibition is a publication and the exhibition of these photographs is supported by LURF.

A Machine for Feeling: Ping's Posthuman Affect

Beckett's famous claim that his writing seeks to ‘work on the nerves of the audience, not the intellect’ points to the centrality of affect in his work. But while his writing's affective quality is widely acknowledged by readers of his work, its refusal of intellect has made it difficult to take fully into account in scholarly work on Beckett. Taking Beckett's 1967 short prose text Ping as a case study, this essay is an attempt to take the affective qualities of Beckett's writing seriously and to consider the implications of his affectively dense writing for his texts’ relationship to history. I argue that Ping's affect emerges from the rhythms of its prose, producing a highly ‘speakable’ text in which affect precedes interpretation. In Ping, however, this affective rhythmic patterning is portrayed as mechanical, the product of the machinic ‘ping’ that punctuates the text and the text's own mechanical rhythms, demanding the active involvement of the reader. The essay concludes by arguing that Ping's mechanised affect is a specifically historical feeling. Arising from a specifically twentieth-century anxiety about technology's tendency to evacuate ‘natural’ emotion in favour of inhuman affect, it participates in a tradition of affectively resonant but curiously blank or indifferent performances of cyborg embodiment. Read in this historical light, Ping's implication of the reader in the production of its mechanised affect grants it, from our contemporary perspective, an archival quality. At the same time, it asks us to broaden the way in which we understand the Beckettian text's relationship to history, pointing to the existence of a more complex and recursive relationship between literature, its historical moment, and our contemporary moment of reading. Such a post-archival historicism sees texts as generated by but not bound to their historical moments of composition, and understands the moment of reception as an integral, if shifting, part of the text's history.

Digitizing oral history: can you hear the difference?

Purpose – The purpose of this study is to answer the questions: Can students discern the difference between oral histories digitized at archival quality (96 kHz/24-bit) versus CD-quality (44.1 kHz/16-bit)? and How important do they believe this difference is? Digitization of analog audio recordings has become the recommended best practice in preserving and making available oral histories. Additionally, well-accepted standards in performing this work are available. However, there is relatively little research that addresses if individuals can hear a qualitative difference in recordings made with best practices versus those that have not. Design/methodology/approach – In all, 53 individuals participated in the study, where they listened to three sets of oral histories and had to decide which was the archival-quality recording versus the CD-quality recording and mark their answer on a survey. Findings – Students could discern less than half of the time on average which was the archival quality versus the CD-quality recording. Further, after listening to the differences, they most often indicated the difference was “a little bit important”. Practical implications – This research does not suggest that archivists abandon well-established sound digitization practices that produce results that audio archivists (and those able to hear fine-grain audio differences) find superior. Rather, it does imply that additional work may be needed to train listeners to discern these fine-grain differences, and appreciate the highest-fidelity replication of original audio recordings. Originality/value – This research addresses a gap in the literature by connecting audio digitization practices to its impact on listener perception.