Evaluation of ATMS cross track asymmetry

2012 ◽  
Author(s):  
Tong Zhu ◽  
Fuzhong Weng
Keyword(s):  
Cross Track

Evolution of Peroxyacetyl Nitrate (PAN) in wildfire smoke plumes detected by the Cross-Track Infrared Sounder (CrIS) over the western U.S. during summer 2018.

2021 ◽  
Author(s):  
Julieta F. Juncosa Calahorrano ◽  
Vivienne H. Payne ◽  
Susan Kulawik ◽  
Bonne Ford ◽  
Frank Flocke ◽  
...  
Keyword(s):  
Peroxyacetyl Nitrate ◽  
Wildfire Smoke ◽  
Smoke Plumes ◽  
The Cross ◽  
Cross Track

scholarly journals The Estimation of Angular Misalignments for Ultra Short Baseline Navigation Systems. Part II: Experimental Results

2013 ◽  
Vol 66 (5) ◽  
pp. 773-787 ◽  
Author(s):  
Hsin-Hung Chen
Keyword(s):  
Trial Data ◽  
Experimental Results ◽  
Experimental Result ◽  
Alignment Error ◽  
Navigation Systems ◽  
Analytical Prediction ◽  
Short Baseline ◽  
Sea Trial ◽  
Alignment Errors ◽  
Cross Track

An algorithm of alignment calibration for Ultra Short Baseline (USBL) navigation systems was presented in the companion work (Part I). In this part (Part II) of the paper, this algorithm is tested on the sea trial data collected from USBL line surveys. In particular, the solutions to two practical problems referred to as heading deviation and cross-track error in the USBL line survey are presented. A field experiment running eight line surveys was conducted to collect USBL positioning data. The numerical results for the sea trial data demonstrated that the proposed algorithm could robustly and effectively estimate the alignment errors. Comparisons of the experimental result with the analytical prediction of roll misalignment estimation in Part I is drawn, showing good agreement. The experimental results also show that an inappropriate estimation of roll alignment error will significantly degrade the quality of estimations of heading and pitch alignment errors.

scholarly journals The Coplane Analysis Technique for Three-Dimensional Wind Retrieval Using the HIWRAP Airborne Doppler Radar

2015 ◽  
Vol 54 (3) ◽  
pp. 605-623 ◽  
Author(s):  
Anthony C. Didlake ◽  
Gerald M. Heymsfield ◽  
Lin Tian ◽  
Stephen R. Guimond
Keyword(s):  
Global Optimization ◽  
Doppler Radar ◽  
Three Dimensional ◽  
Optimization Method ◽  
Vertical Wind ◽  
Wind Component ◽  
Global Optimization Method ◽  
Analysis Technique ◽  
Radar Measurements ◽  
Cross Track

AbstractThe coplane analysis technique for mapping the three-dimensional wind field of precipitating systems is applied to the NASA High-Altitude Wind and Rain Airborne Profiler (HIWRAP). HIWRAP is a dual-frequency Doppler radar system with two downward-pointing and conically scanning beams. The coplane technique interpolates radar measurements onto a natural coordinate frame, directly solves for two wind components, and integrates the mass continuity equation to retrieve the unobserved third wind component. This technique is tested using a model simulation of a hurricane and compared with a global optimization retrieval. The coplane method produced lower errors for the cross-track and vertical wind components, while the global optimization method produced lower errors for the along-track wind component. Cross-track and vertical wind errors were dependent upon the accuracy of the estimated boundary condition winds near the surface and at nadir, which were derived by making certain assumptions about the vertical velocity field. The coplane technique was then applied successfully to HIWRAP observations of Hurricane Ingrid (2013). Unlike the global optimization method, the coplane analysis allows for a transparent connection between the radar observations and specific analysis results. With this ability, small-scale features can be analyzed more adequately and erroneous radar measurements can be identified more easily.

scholarly journals A Simple Model for Simulating Tornado Damage in Forests

2006 ◽  
Vol 45 (12) ◽  
pp. 1597-1611 ◽  
Author(s):  
Andrew P. Holland ◽  
Allen J. Riordan ◽  
E. C. Franklin
Keyword(s):  
Simple Model ◽  
Loblolly Pine ◽  
Forward Speed ◽  
Forward Motion ◽  
Tree Resistance ◽  
Forested Areas ◽  
Storm Characteristics ◽  
Tornado Damage ◽  
Cross Track ◽  
Along Track

Abstract An analytical model is presented to describe patterns of downed trees produced by tornadic winds. The model uses a combined Rankine vortex of specified tangential and radial components to describe a simple tornado circulation. A total wind field is then computed by adding the forward motion of the vortex. The lateral and vertical forces on modeled tree stands are then computed and are compared with physical characteristics of Scots and loblolly pine. From this model, patterns of windfall are computed and are compared to reveal three basic damage patterns: cross-track symmetric, along-track asymmetric, and crisscross asymmetric. These patterns are shown to depend on forward speed, radial speed, and tree resistance. It is anticipated that this model will prove to be useful in assessing storm characteristics from damage patterns observed in forested areas.

Effects of Thermal and Cross-Track Variations for Longitudinal Heat-Assisted Magnetic Recording Systems

2013 ◽  
Vol 770 ◽  
pp. 331-334
Author(s):  
Piya Kovintavewat ◽  
Adisorn Kaewpukdee ◽  
Nitthita Chirdchoo
Keyword(s):  
Magnetic Recording ◽  
Storage Capacity ◽  
Current Data ◽  
Data Recording ◽  
Magnetic Medium ◽  
Recording Technology ◽  
Heat Assisted Magnetic Recording ◽  
Capacity Limit ◽  
Superparamagnetic Limit ◽  
Cross Track

The current data recording technology is approaching its capacity limit approximately 1 Tbit/in2(terabits per square inch) known as superparamagnetic limit. Heat-assisted magnetic recording (HAMR) is one of the promising technologies that is being planned to be used as a new data recording technology to achieve the storage capacity beyond 1 Tbit/in2. In HAMR, the laser is applied to heat a magnetic medium during the writing process, which results in the unique transition characteristics if compared to a conventional system. This paper investigates the effects of thermal and cross-track variations to the transition characteristics (both transition center and transition parameter) of longitudinal HAMR systems. Experimental results indicate that the longitudinal HAMR system can withstand some amount of thermal and cross-track variations and still provides satisfactory system performance.

scholarly journals A two-dimensional Stockwell transform for gravity wave analysis of AIRS measurements

2016 ◽  
Vol 9 (6) ◽  
pp. 2545-2565 ◽  
Author(s):  
Neil P. Hindley ◽  
Nathan D. Smith ◽  
Corwin J. Wright ◽  
D. Andrew S. Rees ◽  
Nicholas J. Mitchell
Keyword(s):  
General Circulation ◽  
Drake Passage ◽  
General Circulation Models ◽  
Two Dimensional ◽  
Atmospheric Infrared Sounder ◽  
Spectral Window ◽  
Energy And Momentum ◽  
Stockwell Transform ◽  
Cross Track ◽  
Along Track

Abstract. Gravity waves (GWs) play a crucial role in the dynamics of the earth's atmosphere. These waves couple lower, middle and upper atmospheric layers by transporting and depositing energy and momentum from their sources to great heights. The accurate parameterisation of GW momentum flux is of key importance to general circulation models but requires accurate measurement of GW properties, which has proved challenging. For more than a decade, the nadir-viewing Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite has made global, two-dimensional (2-D) measurements of stratospheric radiances in which GWs can be detected. However, one problem with current one-dimensional methods for GW analysis of these data is that they can introduce significant unwanted biases. Here, we present a new analysis method that resolves this problem. Our method uses a 2-D Stockwell transform (2DST) to measure GW amplitudes, horizontal wavelengths and directions of propagation using both the along-track and cross-track dimensions simultaneously. We first test our new method and demonstrate that it can accurately measure GW properties in a specified wave field. We then show that by using a new elliptical spectral window in the 2DST, in place of the traditional Gaussian, we can dramatically improve the recovery of wave amplitude over the standard approach. We then use our improved method to measure GW properties and momentum fluxes in AIRS measurements over two regions known to be intense hotspots of GW activity: (i) the Drake Passage/Antarctic Peninsula and (ii) the isolated mountainous island of South Georgia. The significance of our new 2DST method is that it provides more accurate, unbiased and better localised measurements of key GW properties compared to most current methods. The added flexibility offered by the scaling parameter and our new spectral window presented here extend the usefulness of our 2DST method to other areas of geophysical data analysis and beyond.

scholarly journals Deriving the slit functions from OMI solar observations and its implications for ozone-profile retrieval

2017 ◽  
Vol 10 (10) ◽  
pp. 3677-3695 ◽  
Author(s):  
Kang Sun ◽  
Xiong Liu ◽  
Guanyu Huang ◽  
Gonzalo González Abad ◽  
Zhaonan Cai ◽  
...  
Keyword(s):  
Atmospheric Composition ◽  
Half Maximum ◽  
Ozone Monitoring Instrument ◽  
Gaussian Functions ◽  
Solar Observations ◽  
Ozone Profile ◽  
Retrieval Algorithms ◽  
Ozone Monitoring ◽  
Cross Track ◽  
Over Time

Abstract. The Ozone Monitoring Instrument (OMI) has been successfully measuring the Earth's atmospheric composition since 2004, but the on-orbit behavior of its slit functions has not been thoroughly characterized. Preflight measurements of slit functions have been used as a static input in many OMI retrieval algorithms. This study derives on-orbit slit functions from the OMI irradiance spectra assuming various function forms, including standard and super-Gaussian functions and a stretch to the preflight slit functions. The on-orbit slit functions in the UV bands show U-shaped cross-track dependences that cannot be fully represented by the preflight ones. The full widths at half maximum (FWHM) of the stretched preflight slit functions for detector pixels at large viewing angles are up to 30 % larger than the nadir pixels for the UV1 band, 5 % larger for the UV2 band, and practically flat in the VIS band. Nonetheless, the on-orbit changes of OMI slit functions are found to be insignificant over time after accounting for the solar activity, despite of the decaying of detectors and the occurrence of OMI row anomaly. Applying the derived on-orbit slit functions to ozone-profile retrieval shows substantial improvements over the preflight slit functions based on comparisons with ozonesonde validations.

Sign in / Sign up

Export Citation Format

Share Document