scholarly journals Questions on utilization of different height balloon sources of optical radiation for calibration of network of ground microtelescopes for tracking of orbital satellites

2020 ◽  
Vol 4 (1) ◽  
pp. 14-19
Author(s):  
H. H. Asadov ◽  
U. F. Mamedova
Keyword(s):  
Optical Radiation ◽  
Spectral Characteristics ◽  
Calibration Procedure ◽  
High Accuracy ◽  
Laser Beams ◽  
Optimum Type ◽  
Laser Sources ◽  
Time Utilization ◽  
Stable Laser ◽  
Maximum Utilization

One of ways to increase accuracy of ground tracking of orbital satellites is high accuracy calibration of network of microtelescopes used for this purpose. To attain high accuracy utilization of stable laser sources of radiation is most expedient. To install such sources the balloon platforms mounted at some height are practiced. But utilization of only one fixed height of all sources for calibration could lead to insufficient value of signal/noise ratio due to unpredictable atmospheric events. At the same time utilization of sources with different spectral characteristics can complicate the required methodic for analysis. Authors suggest utilization of same type lasers and carrying out of calibration using platforms installed at different heights. Nonapparent function of dependence of laser beams divergence on height of balloon installation is considered for analysis. Some integrated limitation is imposed on this function. It is assumed that number of microtelescopes receiving optical radiation of one source linearly depends on height of the source. It is required to find out the optimum type of suggested non-apparent function upon which target functional composed as sum of all calibration signals could reach maximum. Utilization of such property of target functional for checking up of carried out calibration procedure is suggested. Providing for the required type of suggested non-apparent function is technically resolvable task because the beam divergence is controlled parameter and height of platform can be measured with sufficient accuracy.

scholarly journals Stimulated Raman Microscopy Implemented by Three Femtosecond Laser Sources

2021 ◽  
Vol 255 ◽  
pp. 06003
Author(s):  
Rajeev Ranjan ◽  
Maria Antonietta Ferrara ◽  
Luigi Sirleto
Keyword(s):  
Femtosecond Laser ◽  
Stimulated Raman Scattering ◽  
Second Harmonic ◽  
Laser Beams ◽  
Raman Gain ◽  
Harmonic Generator ◽  
Second Harmonic Generator ◽  
Laser Sources ◽  
Fingerprint Region ◽  
Stimulated Raman

In this work, the implementation of a femtosecond Stimulated Raman Scattering microscope, equipped with three femtosecond laser sources: a Titanium-Sapphire (Ti:Sa), an optical parametric oscillator (OPO), and a second harmonic generator (SHG); is presented. Our microscope is designed so that it can cover all the regions of Raman spectra, taking advantage of two possible laser combinations. The first, Ti:Sa and OPO laser beams, which cover the C-H region (>2800 cm-1 ) in stimulated Raman gain (SRG) modality, whereas the second, Ti:Sa and SHG laser beams, covering the C-H region and the fingerprint region in stimulated Raman losses (SRL) modality. The successful realization of the microscope is demonstrated, reporting images of polystyrene beads using both SRL and SRG modalities.

Highly stable, monochromatic and tunable optical radiation source and its application to high accuracy spectrophotometry

1992 ◽  
Vol 31 (4) ◽  
pp. 536 ◽  
Author(s):  
Valerie E. Anderson ◽  
Nigel P. Fox ◽  
David H. Nettleton
Keyword(s):  
Radiation Source ◽  
Optical Radiation ◽  
High Accuracy

Measurement and analysis of wavefront structures of diode lasers

2017 ◽  
Vol 84 (1) ◽  
Author(s):  
Inga-Maria Eichentopf ◽  
Martin Reufer
Keyword(s):  
Semiconductor Lasers ◽  
Near Infrared ◽  
Beam Quality ◽  
Laser Beams ◽  
Modal Composition ◽  
Wavefront Analysis ◽  
Measurement And Analysis ◽  
Laser Sources ◽  
Insight Into

AbstractIn order to analyze the beam quality of laser sources wavefront measurements using a Shack–Hartmann sensor became an established way. With the detection of the wavefront deflection a change of the modal composition of the laser beam can be recorded directly. While this method is well known for nearly Gaussian laser beams, the wavefront analysis of broadarea semiconductor lasers is an open field of current research. Detailed analysis of the wavefront gives an additional path to get an insight into the transverse modal composition of semiconductor lasers, which have a dominant impact on the output parameters of the devices. For the presented investigations lasers emitting light in the near infrared (

Non-coherent optical radiation sources

2015 ◽  
Author(s):  
David K Taylor
Keyword(s):  
Clinical Practice ◽  
Optical Radiation ◽  
Clinical Settings ◽  
Diagnosis And Therapy ◽  
Radiation Sources ◽  
Laser Sources

Optical radiation is ubiquitous, and intense artificial sources find many applications in clinical practice, including zone illumination, diagnosis, and therapy. Its effects on humans are strongly wavelength-dependent, its hazards sometimes overlooked due to familiarity or masking by other wavelengths. This chapter examines non-laser sources of ultraviolet, visible, and infrared radiations, the risks likely to be encountered in clinical settings, the calculations needed to assess commonly encountered optical radiation sources, and the measures that can be taken to minimize the hazards to workers and patients, in compliance with the requirements of the Artificial Optical Radiation directive.

scholarly journals Twilight tropospheric and stratospheric photodissociation rates derived from balloon borne radiation measurements

2003 ◽  
Vol 3 (2) ◽  
pp. 377-385 ◽  
Author(s):  
A. Kylling ◽  
T. Danielsen ◽  
M. Blumthaler ◽  
J. Schreder ◽  
B. Johnsen
Keyword(s):  
State Of The Art ◽  
Spectral Characteristics ◽  
Calibration Procedure ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Balloon Flight ◽  
Center Wavelength ◽  
Model Simulations ◽  
Stratospheric Balloon ◽  
Radiation Measurements

Abstract. A new ligthweight multichannel moderate bandwidth filter instrument designed to be flown on balloons, is described. The instrument measures the radiation field within the short UV (center wavelength at 312 nm) and long UV (center wavelength at 340 nm). The angular and spectral characteristics of the instrument are discussed and the calibration procedure outlined. Measurements made during a stratospheric balloon flight at twilight conditions from Gap-Tallard, France, are presented and compared with state-of-the-art radiative transfer model simulations. The model simulations and the measurements agree within ±10% (±20%) for solar zenith angles smaller than 93° (90°) for the 340 (312) nm channel. Based on the model simulations of the measured radiation, actinic flux spectra are reconstructed. These are used to calculate various photodissociation rates.

scholarly journals An online diagnosis technique for simultaneous measurement of the fundamental, second and third harmonics in one snapshot

2019 ◽  
Vol 7 ◽  
Author(s):  
Xue Dong ◽  
Xingchen Pan ◽  
Cheng Liu ◽  
Jianqiang Zhu
Keyword(s):  
Random Phase ◽  
High Accuracy ◽  
Measurement Methods ◽  
Laser Beams ◽  
Phase Plate ◽  
Diffraction Intensity ◽  
Compact Structure ◽  
Laser Driver ◽  
Diffraction Patterns ◽  
Diagnosis Technique

A three-wavelength coherent-modulation-imaging (CMI) technique is proposed to simultaneously measure the fundamental, second and third harmonics of a laser driver in one snapshot. Laser beams at three wavelengths (1053 nm, 526.5 nm and 351 nm) were simultaneously incident on a random phase plate to generate hybrid diffraction patterns, and a modified CMI algorithm was adopted to reconstruct the complex amplitude of each wavelength from one diffraction intensity frame. The validity of this proposed technique was verified using both numerical simulation and experimental analyses. Compared to commonly used measurement methods, this proposed method has several advantages, including a compact structure, convenient operation and high accuracy.

scholarly journals A Novel Calibration Method of Articulated Laser Sensor for Trans-Scale 3D Measurement

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1083 ◽  
Author(s):  
Jiehu Kang ◽  
Bin Wu ◽  
Xiaodeng Duan ◽  
Ting Xue
Keyword(s):  
Measurement Instrument ◽  
Calibration Method ◽  
High Accuracy ◽  
Industrial Applications ◽  
Laser Beams ◽  
Laser Sensor ◽  
3D Measurement ◽  
System Parameters ◽  
Laser Sensing ◽  
Processing Techniques

The articulated laser sensor is a new kind of trans-scale and non-contact measurement instrument in regular-size space and industrial applications. These sensors overcome many deficiencies and application limitations of traditional measurement methods. The articulated laser sensor consists of two articulated laser sensing modules, and each module is made up of two rotary tables and one collimated laser. The three axes represent a non-orthogonal shaft architecture. The calibration method of system parameters for traditional instruments is no longer suitable. A novel high-accuracy calibration method of an articulated laser sensor for trans-scale 3D measurement is proposed. Based on perspective projection models and image processing techniques, the calibration method of the laser beam is the key innovative aspect of this study and is introduced in detail. The experimental results show that a maximum distance error of 0.05 mm was detected with the articulated laser sensor. We demonstrate that the proposed high-accuracy calibration method is feasible and effective, particularly for the calibration of laser beams.

scholarly journals Contribution to solving the orientation problem for an automatic magnetic observatory

2013 ◽  
Vol 2 (1) ◽  
pp. 1-9 ◽  
Author(s):  
A. Khokhlov ◽  
J. L. Le Mouël ◽  
M. Mandea
Keyword(s):  
Vertical Component ◽  
Calibration Procedure ◽  
High Accuracy ◽  
Absolute Calibration ◽  
Magnetic Observatory ◽  
Time Interval ◽  
Internal Calibration ◽  
Scale Factors ◽  
The Absolute ◽  
Absolute Measurements

Abstract. The problem of the absolute calibration of a vectorial (tri-axial) magnetometer is addressed with the objective that the apparatus, once calibrated, gives afterwards, for a few years, the absolute values of the three components of the geomagnetic field (say the Northern geographical component, Eastern component and vertical component) with an accuracy on the order of 1 nT. The calibration procedure comes down to measure the orientation in space of the three physical axes of the sensor or, in other words, the entries of the transfer matrix from the local geographical axes to these physical axes. Absolute calibration follows indeed an internal calibration which provides accurate values of the three scale factors corresponding to the three axes – and in addition their relative angles. The absolute calibration can be achieved through classical absolute measurements made with an independent equipment. It is shown – after an error analysis which is not trivial – that, while it is not possible to get the axes absolute orientations with a high accuracy, the assigned objective (absolute values of the Northern geographical component, Eastern component and vertical component, with an accuracy of the order of 1 nT) is nevertheless reachable; this is because in the time interval of interest the field to measure is not far from the field prevailing during the calibration process.

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