scholarly journals A New Method for Characterizing NOAA-20/S-NPP VIIRS Thermal Emissive Bands Response Versus Scan Using On-Orbit Pitch Maneuver Data

2019 ◽  
Vol 11 (13) ◽  
pp. 1624
Author(s):  
Wenhui Wang ◽  
Changyong Cao ◽  
Slawomir Blonski
Keyword(s):  
Test Data ◽  
Infrared Imaging ◽  
New Method ◽  
Temperature Dependent ◽  
Significant Contributor ◽  
Comparison Results ◽  
Response Versus ◽  
Cross Track

The on-orbit calibration of Visible Infrared Imaging Radiometer Suite (VIIRS) Thermal Emissive Bands (TEB), onboard the National Oceanic and Atmospheric Administration-20 (NOAA-20) and the Suomi National Polar-orbiting Partnership (S-NPP) satellites, have been stable during nominal operations. However, larger than expected scan angle/scene temperature dependent biases, relative to the co-located Cross-track Infrared Sounder (CrIS) observations, were observed in the NOAA-20 longwave infrared (LWIR) bands. The Response Versus Scan (RVS) effect—the variation of instrument reflectance of source radiance with scan angle, is a significant contributor to VIIRS calibration. TEB RVS is characterized using prelaunch test data and verified on-orbit using pitch maneuver data. This study presents a new method that characterizes VIIRS on-orbit TEB RVS at both Earth View (EV) and Space View (SV) scan angles simultaneously. This method was compared with an existing on-orbit RVS method (the Wu et al. method), which derives RVS at EV scan angles using pitch maneuver data and extrapolates SV RVS from EV. The new method derived on-orbit RVS differ from prelaunch values up to 1.0% at the beginning of scan in the NOAA-20 LWIR bands, and ~0.5% in S-NPP M15. VIIRS–CrIS inter-comparison results indicates that the new method derived on-orbit RVS can effectively minimize LWIR scan angle/scene temperature dependent biases, with scan averaged biases reduced from 0.40K to 0.15K for NOAA-20 LWIR bands, and from 0.24K to 0.08K for S-NPP M15. The Wu et al. method can also reduce the scan angle dependent biases, but at the expense of increasing the scene temperature dependent biases.

scholarly journals A New 32-Day Average-Difference Method for Calculating Inter-Sensor Calibration Radiometric Biases between SNPP and NOAA-20 Instruments within ICVS Framework

2021 ◽  
Vol 13 (16) ◽  
pp. 3079
Author(s):  
Banghua Yan ◽  
Mitch Goldberg ◽  
Xin Jin ◽  
Ding Liang ◽  
Jingfeng Huang ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Satellite System ◽  
Advanced Technology ◽  
New Method ◽  
Double Difference ◽  
Sensor Calibration ◽  
Long Term Trends ◽  
Cross Track ◽  
Radiative Transfer Modeling

Two existing double-difference (DD) methods, using either a 3rdSensor or Radiative Transfer Modeling (RTM) as a transfer, are applicable primarily for limited regions and channels, and, thus critical in capturing inter-sensor calibration radiometric bias features. A supplementary method is also desirable for estimating inter-sensor calibration biases at the window and lower sounding channels where the DD methods have non-negligible errors. In this study, using the Suomi National Polar-orbiting Partnership (SNPP) and Joint Polar Satellite System (JPSS)-1 (alias NOAA-20) as an example, we present a new inter-sensor bias statistical method by calculating 32-day averaged differences (32D-AD) of radiometric measurements between the same instrument onboard two satellites. In the new method, a quality control (QC) scheme using one-sigma (for radiance difference), or two-sigma (for radiance) thresholds are established to remove outliers that are significantly affected by diurnal biases within the 32-day temporal coverage. The performance of the method is assessed by applying it to estimate inter-sensor calibration radiometric biases for four instruments onboard SNPP and NOAA-20, i.e., Advanced Technology Microwave Sounder (ATMS), Cross-track Infrared Sounder (CrIS), Nadir Profiler (NP) within the Ozone Mapping and Profiler Suite (OMPS), and Visible Infrared Imaging Radiometer Suite (VIIRS). Our analyses indicate that the globally-averaged inter-sensor differences using the 32D-AD method agree with those using the existing DD methods for available channels, with margins partially due to remaining diurnal errors. In addition, the new method shows its capability in assessing zonal mean features of inter-sensor calibration biases at upper sounding channels. It also detects the solar intrusion anomaly occurring on NOAA-20 OMPS NP at wavelengths below 300 nm over the Northern Hemisphere. Currently, the new method is being operationally adopted to monitor the long-term trends of (globally-averaged) inter-sensor calibration radiometric biases at all channels for the above sensors in the Integrated Calibration/Validation System (ICVS). It is valuable in demonstrating the quality consistencies of the SDR data at the four instruments between SNPP and NOAA-20 in long-term statistics. The methodology is also applicable for other POES cross-sensor calibration bias assessments with minor changes.

scholarly journals A simple method for determining seismic demands on gravity load frames

2017 ◽  
Vol 44 (8) ◽  
pp. 661-673 ◽  
Author(s):  
J. Beauchamp ◽  
P. Paultre ◽  
P. Léger
Keyword(s):  
Response Spectrum ◽  
Time History ◽  
Bending Moment ◽  
New Method ◽  
Simple Method ◽  
Seismic Demands ◽  
Gravity Load ◽  
Comparison Results ◽  
Seismic Force ◽  
Nonlinear Time History

This paper presents a simple method based on modal response spectrum analysis to compute internal forces in structural elements belonging to gravity framing not part of the seismic force resisting system (SFRS). It is required that demands on these gravity load resisting system (GLRS) be determined according to the design displacement profile of the SFRS. The proposed new method uses the fact that if the linear stiffness properties of the GLRS not part of the SFRS have negligible values compared to those of the SFRS, only the latter will provide lateral resistance. Displacements of the GLRS then correspond to those of the SFRS alone. The new method is illustrated by computing the seismic responses of a symmetric and an asymmetric multi-storey reinforced concrete building. These results are compared to those obtained from the application of the simplified analysis method proposed in the Canadian standard for the design of concrete structures. Nonlinear time history analyses are also performed to provide a benchmark for comparison. Results show that the new method can predict shear and bending moment in all members at once with ease. Therefore, this new simplified method can effectively be used to predict seismic forces in elements not considered part of the SFRS.

Constitutive Equations for Tensile and Creep Behavior of a 9 Cr-1 MO Steel

1975 ◽  
Vol 97 (4) ◽  
pp. 258-263
Author(s):  
F. V. Ellis ◽  
J. E. Bynum ◽  
B. W. Roberts
Keyword(s):  
Constitutive Equation ◽  
Test Data ◽  
Constitutive Equations ◽  
Tensile Tests ◽  
Temperature Dependent ◽  
Creep Tests ◽  
Creep Properties ◽  
Hardening Mechanism ◽  
Strain Relationship ◽  
Analysis Computer

This paper describes an investigation of the tensile and creep properties of annealed 9 Cr-1 Mo steel. Tensile tests were conducted at temperatures from 70 to 1050 F while creep tests were conducted at 750, 850, 950, and 1050 F with stresses from 4 to 52 ksi. From the tensile test data, a constitutive equation was developed for the stress-plastic strain relationship. This equation was based on a two-stage hardening mechanism and combined power law and exponential functions. From the creep test data, isochronous stress-strain curves were constructed out to 104 hr. These curves were extrapolated to 105 hr and to lower stresses using a parametric analysis procedure. Additionally, a creep constitutive equation capable of describing the total creep curve, including the tertiary region, was developed. This equation, having three stress and temperature dependent parameters predicted creep curves which were in good agreement with the actual curves. Both the time-independent (tensile) and time-dependent (creep) constitutive equations are suitable for use in finite element stress analysis computer programs.

Constitutive Model of Supper-Alloy IN625 Based on Extrusion Test

2011 ◽  
Vol 314-316 ◽  
pp. 819-822 ◽  
Author(s):  
Zhong Tang Wang ◽  
Shi Hong Zhang ◽  
Ming Cheng ◽  
De Fu Li
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Test Data ◽  
Arrhenius Equation ◽  
New Method ◽  
Extrusion Speed ◽  
Material Constitutive Model ◽  
Model Based ◽  
Calculation Results ◽  
Relative Errors

Abstract: It had been put forward that a new method to establish material constitutive model based on extrusion test, which was that the material constitutive model was determined with the Arrhenius equation according to the extrusion test data. The tube extruding test of supper-alloy Inconel625(IN625) had been done on 16300kN extrusion machine. According to the extrusion test data and the Arrhenius equation, it had been determined that the constitutive model of supper-alloy IN625 based on extrusion test, and the relative errors between calculation results of the model and experiment results are less than 7.8%. The suitable conditions of the constitutive model of supper-alloy IN625 are that the temperature being 1150°C～1200°C, and extrusion speed being 15～60mm/s, and strain-rate being 1.86～7.44.

Moving Target Tracking Using Sparse Optical Flow Method

2013 ◽  
Vol 718-720 ◽  
pp. 2335-2339
Author(s):  
Tian Ding Chen ◽  
Jian Hu ◽  
Chao Lu ◽  
Zhong Jiao He
Keyword(s):  
Optical Flow ◽  
Target Tracking ◽  
New Method ◽  
Moving Target ◽  
Tracking Accuracy ◽  
Experimental Conditions ◽  
Moving Target Tracking ◽  
Research Production ◽  
Harris Corner ◽  
Comparison Results

Moving target tracking is a hot research spot of computer vision and applied in various fields. In this paper, a new tracking method base on sparse optical flow is put forward. In this method, targets are tracked through calculating the movements of Harris corner points, rather than the movements of all pixel points. Experiments results show that the tracking effect of this new method is pretty good. Tracking accuracy can reach more than 80% in most experimental conditions. And according to other peoples research production, experiments based on dense optical flow are done to compare with the new method proposed in this paper. The comparison results show that the new method has high calculation efficiency. This indicates that the method has feasibility and practical value.

scholarly journals COMPARISON OF STATIC AND DYNAMIC LASER BASED POSITIONING METHODS FOR CHARACTERIZATION OF CNC MACHINES

2018 ◽  
Vol 18 (4) ◽  
pp. 39-46
Author(s):  
Grzegorz BUDZYN ◽  
Janusz RZEPKA ◽  
Pawel KALUZA
Keyword(s):  
Dynamic Method ◽  
Static Method ◽  
New Method ◽  
Measurement Time ◽  
Cnc Machines ◽  
Comparison Results ◽  
Measuring Machine

In the paper we compare the laser based measurements of linear parameters of numerically controlled machines. A new dynamic method of measuring machine positioning is described and compared with the widely used static method. The algorithms of the dynamic method are presented and the comparison results of both methods are shown. It is proven that with the new method the measurement time of linear errors of the CNC machines can be reduced significantly. Additionally the machine wear-out in the linear axes can also be easily and efficiently monitored.

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