A low cost interrogation scheme is demonstrated for a refractometer based on an in-line fiber long period grating ͑LPG͒ Mach-Zehnder interferometer. Using this interrogation scheme the minimum detectable change in refractive index of ⌬nϳ1.8ϫ10 Ϫ6 is obtained, which is the highest resolution achieved using a fiber LPG device, and is comparable to precision techniques used in the industry including high performance liquid chromatography and ultraviolet spectroscopy.

A long period grating is interrogated with a fibre Bragg grating using a derivative spectroscopy technique. A quasi-linear relationship between the output of the sensing scheme and the curvature experienced by the long period grating is demonstrated, with a sensitivity of 5.05 m and with an average curvature resolution of 2.9 × 10 −2 m −1 . In addition, the feasibility of multiplexing an in-line series of long period gratings with this interrogation scheme is demonstrated with two pairs of fibre Bragg gratings and long period gratings. With this arrangement the cross-talk error between channels was less than ±2.4 × 10 −3 m −1 .

Summary The upcoming migration of satellite services to higher bands, namely, the Ka‐ and Q/V‐bands, offers many advantages in terms of bandwidth and system capacity. However, it poses challenges as propagation effects introduced by the various atmospheric phenomena are particularly pronounced in these bands and can become a serious constraint in terms of system reliability and performance. This paper presents the goals, organisation, and preliminary results of an ongoing large‐scale European coordinated propagation campaign using the Alphasat Aldo Paraboni Ka/Q band signal payload on satellite, performed by a wide scientific consortium in the framework of a European Space Agency (ESA) project. The main objective of this activity is the experimental characterisation of the spatial and temporal correlation over Europe of the radio channel at Ka and Q band for future modelling activities and to collect data for development and testing of fading mitigation techniques.

Ventouras, S. ; Reeves, R. ; Rumi, E. ; Perez-Fontan, F. ; Machado, F. ; Pastoriza, V. ; Rocha, A. ; Mota, S. ; Jorge, F. ; Panagopoulos, A.D. ; Papafragkakis, A.Z. ; Kourogiorgas, C.I. ; Fiser, O. ; Pek, V. ; Pesice, P. ; Grabner, B. ; Vilhar, A. ; Kelmendi, A. ; Hrovat, A. ; VanhoenackerJanvier, Danielle ; Graziani, Alberto ; Quibus, Laurent ; Goussetis, G. ; Martellucci, A. AbstractThe upcoming migration of satellite services to higher bands, namely the Kaand Q-bands offers many advantages in terms of bandwidth, data rates and system capacity. However, it poses challenges as propagation effects introduced by the various atmospheric phenomena are particularly pronounced in these bands and can become a serious constraint in terms of system reliability and performance. This paper outlines the goals, organization and some first results of an ongoing large propagation campaign consortium formed across Europe under the supervision of the European Space Agency; the campaign, shall ultimately assist in the validation and development of channel models targeting thesebands. Finally, the consideration of diverse climatic conditions and elevation angles along with the evaluation of the frequency and spatio-temporal effects, shall support the development of Fading and Mitigation Techniques and their assessment using real data. Abstract-The upcoming migration of satellite services to higher bands, namely the Ka-and Q-bands offers many advantages in terms of bandwidth, data rates and system capacity. However, it poses challenges as propagation effects introduced by the various atmospheric phenomena are particularly pronounced in these bands and can become a serious constraint in terms of system reliability and performance. This paper outlines the goals, organization and some first results of an ongoing large propagation campaign consortium formed across Europe under the supervision of the European Space Agency; the campaign, shall ultimately assist in the validation and development of channel models targeting these-bands. Finally, the consideration of diverse climatic conditions and elevation angles along with the evaluation of the frequency and spatio-temporal effects, shall support the development of Fading and Mitigation Techniques and their assessment using real data.

We demonstrate the use of a series of in-line fibre long period grating curvature sensors on a garment, used to monitor the thoracic and abdominal volumetric tidal movements of a human subject. These results are used to obtain volumetric tidal changes of the human torso showing reasonable agreement with a spirometer used simultaneously to record the volume at the mouth during breathing. The curvature sensors are based upon long period gratings written in a progressive three layered fibre that are insensitive to refractive index changes. The sensor platform consists of the long period grating laid upon a carbon fibre ribbon, which is encapsulated in a low temperature curing silicone rubber.