scholarly journals Sampling flying bats with thermal and near-infrared imaging and ultrasound recording: hardware and workflow for bat point counts

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 189
Author(s):  
Kevin Darras ◽  
Ellena Yusti ◽  
Andreas Knorr ◽  
Joe Chun-Chia Huang ◽  
Agus Priyono Kartono ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Infrared Camera ◽  
Proof Of Concept ◽  
Data Types ◽  
Flight Pattern ◽  
Point Counts ◽  
Single Method ◽  
Pattern Information ◽  
Subsequent Identification

Bat communities can usually only be comprehensively monitored by combining ultrasound recording and trapping techniques. Here, we propose bat point counts, a novel, single method to sample all flying bats. We designed a sampling rig that combines a thermal scope to detect flying bats and their flight patterns, an ultrasound recorder to identify echolocating bat calls, and a near-infrared camera and LED illuminator to photograph bat morphology. We evaluated the usefulness of the flight pattern information, echolocation call recordings, and near-infrared photographs produced by our sampling rig to determine a workflow to process these heterogenous data types. We present a conservative workflow to enable taxonomic discrimination and identification of bat detections. Our sampling rig and workflow allowed us to detect both echolocating and non-echolocating bats and we could assign 84% of the detections to a guild. Subsequent identification can be carried out with established methods such as identification keys and call libraries, based on the visible morphological features and echolocation calls. Currently, a higher near-infrared picture quality is required to resolve more detailed diagnostic morphology, but there is considerable potential to extract more information with higher-intensity illumination. This is the first proof-of-concept for bat point counts, a method that can passively sample all flying bats in their natural environment.

scholarly journals SUBARU near-infrared multi-color images of Class II Young Stellar Object, RNO91

2006 ◽  
Vol 2 (S237) ◽  
pp. 447-447
Author(s):  
Satoshi Mayama ◽  
Motohide Tamura ◽  
Masahiko Hayashi
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Infrared Camera ◽  
Central Peak ◽  
Class Ii ◽  
Peak Position ◽  
Infrared Light ◽  
Molecular Outflows ◽  
The North ◽  
Optical Images

AbstractRNO91 is class II source currently in a transition phase between a protostar and a main-sequence star. It is known as a source of complex molecular outflows. Previous studies suggested that RNO91 was associated with a reflection nebula, a CO outflow, shock-excited H2 emission, and disk type structure. But the geometry of RNO91, especially its inner region, is not well confirmed yet. High resolution imaging is needed to understand the nature of RNO91 and its interaction with outflow. Thus, we conducted near-infrared imaging observations of RNO91 with the infrared camera CIAO mounted on the Subaru 8.2-m Telescope. We presented JHK band and optical images which resolved a complex asymmetrical circumstellar structure. We examined the color of RNO91 nebula and compared the geometry of the system suggested by our data with that already proposed on the basis of other studies. Our main results are as follows; 1. The K-band images show significant halo emission detected within ~2″ around the peak position while less halo emission is seen in shorter wavelength images such as J and optical. The nebula appears to become more circular and more diffuse with increasing wavelengths. The cut-off at 300AU derived from our radial surface brightness is consistent with the size of the polarization disk suggested by Draper & Tadhunter (1993). These consistencies indicate that this optically thick region is attributed to a disk-like structure.2. At J and optical, several bluer knot-like structures are detected around and beyond the halo emission. These bluer knots seen in our images are comparable to the size of the envelope detected in HCO+ emission surrounding RNO91 (Lee & Ho 2005). It is thus natural to suggest that these bluer knots are the near-infrared light scattered by an envelope structure which is disrupted by molecular outflows.3. The pseudo-true color composite image has an appearance of arc-shaped emission extending to the north and to the east through RNO91. On the counter part of this arc-shaped structure, the nebula appears to become more extended to the southwest from the central peak position in J band and optical images. We interpret these whole structures as a bottom of bipolar cavity seen relatively edge-on opening to the north and south directions.

scholarly journals Bat point counts: a novel bat sampling method shines light on flying bat communities

2021 ◽  
Author(s):  
Kevin Felix Arno Darras ◽  
Ellena Yusti ◽  
Joe Chun-Chia Huang ◽  
Delphine-Clara Zemp ◽  
Agus Priyono Kartono ◽  
...  
Keyword(s):  
Oil Palm ◽  
Near Infrared ◽  
Sampling Methods ◽  
Magnetic Energy ◽  
Infrared Camera ◽  
Sampling Bias ◽  
Taxonomic Resolution ◽  
Point Counts ◽  
Palm Species ◽  
In The Wild

Emerging technologies based on the detection of electro-magnetic energy offer promising opportunities for sampling biodiversity. We exploit their potential bye showing here how they can be used in bat point counts - a novel method to sample flying bats - to overcome shortcomings of traditional sampling methods, and to maximise sampling coverage and taxonomic resolution of this elusive taxon with minimal sampling bias. We conducted bat point counts with a sampling rig combining a thermal scope to detect bats, an ultrasound recorder to obtain echolocation calls, and a near-infrared camera to capture bat morphology. We identified bats with the first dedicated identification key combining acoustic and morphological features, and compared bat point counts to the standard bat sampling methods of mist netting and automated ultrasound recording in three oil palm plantation sites in Indonesia, over nine survey nights. Based on rarefaction and extrapolation sampling curves, we show that bat point counts were the most time-efficient and effective method for sampling the oil palm species pool. Point counts sampled species that tend to avoid nets and those that are not echolocating, and thus cannot be detected acoustically. We identified some bat sonotypes with near-infrared imagery, and bat point counts revealed strong sampling biases in previous studies using capture-based methods, suggesting similar biases in other regions might exist. While capture-based methods allow to identify bats with absolute and internal morphometry, and unattended ultrasound recorders can effectively sample echolocating bats, bat point counts are a promising, and potentially competitive new tool for sampling all flying bats without bias and observing their behavior in the wild.

scholarly journals Near-Infrared Imaging with the 105 cm Kiso Schmidt

1995 ◽  
Vol 148 ◽  
pp. 48-51
Author(s):  
T. Ichikawa ◽  
K. Tarusawa ◽  
K. Yanagisawa ◽  
N. Itoh
Keyword(s):  
Thermal Radiation ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Infrared Camera ◽  
Image Resolution ◽  
Schmidt Telescope ◽  
Near Infrared Imaging ◽  
Large Format ◽  
Nearby Galaxies ◽  
Array Camera

AbstractWe have carried out imaging observations in the near-infrared (J, H and K’ band) with a large format array camera attached to the prime focus of the 105 cm Schmidt telescope at Kiso Observatory. The image resolution, limiting magnitudes and effect of thermal radiation are presented, based on observations of nearby galaxies. Considering the results, we are constructing a new larger near-infrared camera optimized for use with the Kiso Schmidt.

scholarly journals Preliminary status of POLICAN: A near-infrared imaging polarimeter

2014 ◽  
Vol 10 (S305) ◽  
pp. 175-180 ◽  
Author(s):  
R. Devaraj ◽  
A. Luna ◽  
L. Carrasco ◽  
Y. D. Mayya
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Infrared Camera ◽  
Stokes Parameters ◽  
Polarization Angle ◽  
Linear Combinations ◽  
Star Forming ◽  
Star Forming Regions ◽  
Instrumental Polarization ◽  
Sky Survey

AbstractPOLICAN is a near-infrared (J, H, K) imaging polarimeter developed for the Cananea near infrared camera (CANICA) at the 2.1m telescope of the Guillermo Haro Astrophysical Observatory (OAGH) located at Cananea, Sonora, México. The camera has a 1024 x 1024 HgCdTe detector (HAWAII array) with a plate scale of 0.32 arcsec/pixel providing a field of view of 5.5 x 5.5 arcmin. POLICAN is mounted externally to CANICA for narrow-field (f/12) linear polarimetric observations. It consists of a rotating super achromatic (1-2.7μm) half waveplate and a fixed wire-grid polarizer as the analyzer. The light is modulated by setting the half waveplate at different angles (0○, 22.5○, 45○, 67.5○) and linear combinations of the Stokes parameters (I, Q and U) are obtained. Image reduction and removal of instrumental polarization consist of dark noise subtraction, polarimetric flat fielding and background sky subtraction. Polarimetric calibration is performed by observing polarization standards available in the literature. The astrometry correction is performed by matching common stars with the Two Micron All Sky Survey. POLICAN's bright and limiting magnitudes are approximately 6th and 16th magnitude, which correspond to saturation and photon noise, respectively. POLICAN currently achieves a polarimetric accuracy about 3.0% and polarization angle uncertainties within 3○. Preliminary observations of star forming regions are being carried out in order to study their magnetic field properties.

scholarly journals Search for giant planets around seven white dwarfs in the Hyades cluster with the Hubble Space Telescope

2020 ◽  
Vol 500 (3) ◽  
pp. 3920-3925
Author(s):  
Wolfgang Brandner ◽  
Hans Zinnecker ◽  
Taisiya Kopytova
Keyword(s):  
White Dwarfs ◽  
Near Infrared ◽  
Hubble Space Telescope ◽  
Infrared Camera ◽  
Detection Limits ◽  
Giant Planets ◽  
High Angular Resolution ◽  
Mass Detection ◽  
Space Telescope ◽  
Hyades Cluster

ABSTRACT Only a small number of exoplanets have been identified in stellar cluster environments. We initiated a high angular resolution direct imaging search using the Hubble Space Telescope (HST) and its Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument for self-luminous giant planets in orbit around seven white dwarfs in the 625 Myr old nearby (≈45 pc) Hyades cluster. The observations were obtained with Near-Infrared Camera 1 (NIC1) in the F110W and F160W filters, and encompass two HST roll angles to facilitate angular differential imaging. The difference images were searched for companion candidates, and radially averaged contrast curves were computed. Though we achieve the lowest mass detection limits yet for angular separations ≥0.5 arcsec, no planetary mass companion to any of the seven white dwarfs, whose initial main-sequence masses were >2.8 M⊙, was found. Comparison with evolutionary models yields detection limits of ≈5–7 Jupiter masses (MJup) according to one model, and between 9 and ≈12 MJup according to another model, at physical separations corresponding to initial semimajor axis of ≥5–8 au (i.e. before the mass-loss events associated with the red and asymptotic giant branch phase of the host star). The study provides further evidence that initially dense cluster environments, which included O- and B-type stars, might not be highly conducive to the formation of massive circumstellar discs, and their transformation into giant planets (with m ≥ 6 MJup and a ≥6 au). This is in agreement with radial velocity surveys for exoplanets around G- and K-type giants, which did not find any planets around stars more massive than ≈3 M⊙.

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