An airborne pushbroom hyperspectral imager with wide field of view

An airborne pushbroom hyperspectrai imager （APHI） with wide field （42° field of view） is presented. It is composed of two 22° field of view （FOV） imagers and can provide 1304 pixels in spatial dimension, 124 bands in spectral dimension in one frame. APHI has a bandwidth ranging from 400 to 900 nm. The spectral resolution is 5 nm and the spatial resolution is 0.6 m at 1000-m height. The implementation of this system is helpful to overcome the restriction of FOV in pushbroom hyperspectral imaging in a more feasible way. The electronic and optical designs axe also introduced in detail.

The Indian retinopathy of prematurity society:a baby step towards tackling the retinopathy of prematurity epidemic in India

Background:India leads all nations in the number of preterms born annually.With over 3.5 million infants,a reducing infant mortality rate and an expanding base of rural neonatal intensive care units,the number of infants requiring retinopathy of prematurity(ROP)screening has dramatically increased.The number of ROP specialists in the country is currently inadequate.Leading ROP specialists of the country initiated the Indian ROP(IROP)society to address these challenges.Methods:In 2016,the IROP society was conceived and registered as a professional body with a mission to prevent needless blindness from ROP by promoting standards of excellence.A national online membership drive was carried out.The data collected in this survey was analyzed to collate information on past training,practice patterns,ease of screening and treatment,use of wide-field imaging and willingness to be certified.Results:Of the 113 members at the time of submission,67.3%were male.88.5%were formally trained for ROP and 85.8%were vitreo-retinal specialists.Of the practicing members,96%were“comfortable”with screening and 86%with ROP treatment and this correlated with training(P=0.001 and P=0.002 respectively).Only 25.7%performed vitreous surgery for ROP.Wide field imaging was used by 33%of members in their practice and 52%of those who did not,wanted to use it in the future.Members who used imaging performed more number of laser treatments than those who did not(P=0.008).Laser was the preferred modality of treatment for 98%of members.A majority of the members(92.5%)were willing to be audited.Conclusions:The IROP society is a novel platform for ROP specialists to collaborate.The society has setup short,mid and long-term goals to make ROP care more accessible and affordable with appropriate use of technology.

Parallel implementation of w-projection wide-field imaging

w-Projection is a wide-field imaging technique that is widely used in radio synthesis arrays. Processing the wide-field big data generated by the future Square Kilometre Array(SKA) will require significant updates to current methods to significantly reduce the time consumed on data processing. Data loading and gridding are found to be two major time-consuming tasks in w-projection. In this paper, we investigate two parallel methods of accelerating w-projection processing on multiple nodes: the hybrid Message Passing Interface(MPI) and Open Multi-Processing(OpenMP) method based on multicore Central Processing Units(CPUs) and the hybrid MPI and Compute Unified Device Architecture(CUDA)method based on Graphics Processing Units(GPUs). Both methods are successfully employed and operated in various computational environments, confirming their robustness. The experimental results show that the total runtime of both MPI + OpenMP and MPI + CUDA methods is significantly shorter than that of single-thread processing. MPI + CUDA generally shows faster performance when running on multiple nodes than MPI + OpenMP, especially on large numbers of nodes. The single-precision GPU-based processing yields faster computation than the double-precision processing; while the single-and doubleprecision CPU-based processing shows consistent computational performance. The gridding time remarkably increases when the support size of the convolution kernel is larger than 8 and the image size is larger than 2,048 pixels. The present research offers useful guidance for developing SKA imaging pipelines.