How Does the Observation Strategy Influence the Correctness of Alerting Services?

2001 ◽  
pp. 95-103 ◽  
Author(s):  
Annika Hinze
Keyword(s):  
Observation Strategy

scholarly journals Overview of the NOAA/ESRL Federated Aerosol Network

2019 ◽  
Vol 100 (1) ◽  
pp. 123-135 ◽  
Author(s):  
Elisabeth Andrews ◽  
Patrick J. Sheridan ◽  
John A. Ogren ◽  
Derek Hageman ◽  
Anne Jefferson ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Data Access ◽  
Department Of Energy ◽  
Atmospheric Measurements ◽  
Aerosol Radiative Forcing ◽  
Cooperative Program ◽  
Observation Strategy ◽  
The World ◽  
History Of ◽  
Foreign Science

AbstractTo estimate global aerosol radiative forcing, measurements of aerosol optical properties are made by the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory (ESRL)’s Global Monitoring Division (GMD) and their collaborators at 30 monitoring locations around the world. Many of the sites are located in regions influenced by specific aerosol types (Asian and Saharan desert dust, Asian pollution, biomass burning, etc.). This network of monitoring stations is a shared endeavor of NOAA and many collaborating organizations, including the World Meteorological Organization (WMO)’s Global Atmosphere Watch (GAW) program, the U.S. Department of Energy (DOE), several U.S. and foreign universities, and foreign science organizations. The result is a long-term cooperative program making atmospheric measurements that are directly comparable with those from all the other network stations and with shared data access. The protocols and software developed to support the program facilitate participation in GAW’s atmospheric observation strategy, and the sites in the NOAA/ESRL network make up a substantial subset of the GAW aerosol observations. This paper describes the history of the NOAA/ESRL Federated Aerosol Network, details about measurements and operations, and some recent findings from the network measurements.

scholarly journals Impact of temperature field inhomogeneities on the retrieval of atmospheric species from MIPAS IR limb emission spectra

2010 ◽  
Vol 3 (5) ◽  
pp. 1487-1507 ◽  
Author(s):  
M. Kiefer ◽  
E. Arnone ◽  
A. Dudhia ◽  
M. Carlotti ◽  
E. Castelli ◽  
...  
Keyword(s):  
Temperature Field ◽  
Temperature Gradient ◽  
Michelson Interferometer ◽  
Emission Spectra ◽  
Monthly Means ◽  
Atmospheric Species ◽  
Mixing Ratios ◽  
Observation Strategy ◽  
Ch4 And N2o ◽  
Relative Differences

Abstract. We examine volume mixing ratios (vmr) retrieved from limb emission spectra recorded with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board Envisat. In level 2 (L2) data products of three different retrieval processors, which perform one dimensional (1-D) retrievals, we find significant differences between species' profiles from ascending and descending orbit parts. The relative differences vary systematically with time of the year, latitude, and altitude. In the lower stratosphere their monthly means can reach maxima of 20% for CFC-11, CFC-12, HNO3, H2O, 10% for CH4 and N2O. Relative differences between monthly means of 1-D retrieval results and of the true atmospheric state can be expected to reach half of these percentage values, while relative differences in single vmr profiles might well exceed those numbers. Often there are no physical or chemical reasons for these differences, so they are an indicator for a problem in the data processing. The differences are generally largest at locations where the meridional temperature gradient of the atmosphere is strong. On the contrary, when performing the retrieval with a tomographic two dimensional (2-D) retrieval, L2 products generally do not show these differences. This suggests that inhomogeneities in the temperature field, and possibly in the species' fields, which are accounted for in the 2-D algorithm and not in standard 1-D processors, may cause significant deviations in the results. Inclusion of an externally given adequate temperature gradient in the forward model of a 1-D processor helps to reduce the observed differences. However, only the full tomographic 2-D approach is suitable to resolve the horizontal inhomogeneities. Implications for the use of the 1-D data, e.g. for validation, are discussed. The dependence of the ascending/descending differences on the observation strategy suggests that this problem may affect 1-D retrievals of infrared limb sounders, if the line of sight of the instrument has a significant component in the direction of the horizontal temperature variation.

scholarly journals Tomographic reconstruction of atmospheric gravity wave parameters from airglow observations

2017 ◽  
Author(s):  
Rui Song ◽  
Martin Kaufmann ◽  
Jörn Ungermann ◽  
Manfred Ern ◽  
Guang Liu ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Tomographic Reconstruction ◽  
Lower Thermosphere ◽  
Real Data ◽  
Atmospheric Gravity Wave ◽  
Mesopause Region ◽  
Angle Measurements ◽  
Target Mode ◽  
Observation Strategy ◽  
Atmospheric Gravity

Abstract. Gravity waves (GWs) play an important role in atmospheric dynamics. Especially in the mesosphere and lower thermosphere (MLT) dissipating GWs provide a major contribution to the driving of the global wind system. Therefore global observations of GWs in the MLT region are of particular interest. The small scales of GWs, however, pose a major problem for the observation of GWs from space. We propose a new observation strategy for GWs in the mesopause region by combining limb and sub-limb satellite-borne remote sensing measurements for improving the spatial resolution of temperatures that are retrieved from atmospheric soundings. In our study, we simulate satellite observations of the rotational structure of the O2 A-band nightglow. A key element of the new method is the ability of the instrument or the satellite to operate in so called target mode, i.e. to stare at a particular point in the atmosphere and collect radiances at different viewing angles. These multi-angle measurements of a selected region allow for tomographic reconstruction of a 2-dimensional atmospheric state, in particular of gravity wave structures. As no real data is available, the feasibility of this tomographic retrieval is carried out with simulation data in this work. It shows that one major advantage of this observation strategy is that much smaller scale GWs can be observed. We derive a GW sensitivity function, and it is shown that target mode observations are able to capture GWs with horizontal wavelengths as short as ~ 50 km for a large range of vertical wavelengths. This is far better than the horizontal wavelength limit of 100–200 km obtained for conventional limb sounding.

scholarly journals The Magellanic Edges Survey I: Description and first results

2020 ◽  
Vol 497 (3) ◽  
pp. 3055-3075
Author(s):  
L R Cullinane ◽  
A D Mackey ◽  
G S Da Costa ◽  
S E Koposov ◽  
V Belokurov ◽  
...  
Keyword(s):  
Target Selection ◽  
Radial Distance ◽  
Large Magellanic Cloud ◽  
Disc Model ◽  
Observation Strategy ◽  
First Results ◽  
Mass Estimate ◽  
Red Clump ◽  
Red Giant ◽  
Giant Branch Stars

ABSTRACT We present an overview of, and first science results from, the Magellanic Edges Survey (MagES), an ongoing spectroscopic survey mapping the kinematics of red clump and red giant branch stars in the highly substructured periphery of the Magellanic Clouds. In conjunction with Gaia astrometry, MagES yields a sample of ~7000 stars with individual 3D velocities that probes larger galactocentric radii than most previous studies. We outline our target selection, observation strategy, data reduction, and analysis procedures, and present results for two fields in the northern outskirts (>10° on-sky from the centre) of the Large Magellanic Cloud (LMC). One field, located in the vicinity of an arm-like overdensity, displays apparent signatures of perturbation away from an equilibrium disc model. This includes a large radial velocity dispersion in the LMC disc plane, and an asymmetric line-of-sight velocity distribution indicative of motions vertically out of the disc plane for some stars. The second field reveals 3D kinematics consistent with an equilibrium disc, and yields Vcirc = 87.7 ± 8.0 km s−1 at a radial distance of ~10.5 kpc from the LMC centre. This leads to an enclosed mass estimate for the LMC at this radius of (1.8 ± 0.3) × 1010 M⊙.

scholarly journals Monitoring Mining Disturbance and Restoration over RBM Site in South Africa Using LandTrendr Algorithm and Landsat Data

2019 ◽  
Vol 11 (24) ◽  
pp. 6916 ◽  
Author(s):  
Lubanzi Z. D. Dlamini ◽  
Sifiso Xulu
Keyword(s):  
Negative Impact ◽  
Google Earth ◽  
Remotely Sensed Data ◽  
Mining Areas ◽  
Surface Mines ◽  
Automated Method ◽  
Observation Strategy ◽  
Petroleum Resources ◽  
The Status ◽  
Disturbance And Recovery

Considering the negative impact of mining on ecosystems in mining areas, the South African government legislated the Mineral and Petroleum Resources Development Act (No. 28 of 2002), to compel mining companies to restore the land affected by mining. Several studies have used remotely sensed data to observe the status and dynamics of surface mines. Advances in remote sensing along the cloud-based Google Earth Engine (GEE) now promise an enhanced observation strategy for improved monitoring of mine environments. Despite these advances, land rehabilitation at Richards Bay Minerals (RBM) is mainly restricted to field-based approaches which are unable to reveal seamless patterns of disturbance and restoration. Here, we illustrate the value of the trajectory-based LandTrendr algorithm in conjunction with GEE for mine rehabilitation studies. Our automated method produced disturbance and recovery patterns (1984–2018) over the RBM site. The study revealed that RBM has progressively been mining different portions of the mineral-rich coastal area after which restoration was undertaken. The duration of mining over each site ranged from 2 to 6 years. The LandTrendr outputs correspond with independent reference datasets that were classified with an overall accuracy of 99%; it captures mine-induced disturbance efficiently and offers a practical tool for mine restoration management.

GW170817: Swift UV detection of a blue kilonova, and improving the search in O3

2017 ◽  
Vol 13 (S338) ◽  
pp. 53-60
Author(s):  
Aaron Tohuvavohu ◽  
Jamie A. Kennea ◽  
Keyword(s):  
Health And Safety ◽  
X Ray ◽  
Operational Capabilities ◽  
Observation Strategy ◽  
Ongoing Work ◽  
The Galaxy ◽  
Multi Wavelength ◽  
Flexible Planning ◽  
The Impact

AbstractSwift’s rapid slewing, flexible planning, and multi-wavelength instruments make it the most capable space-based follow-up engine for finding poorly localized sources. During O1 and O2 Swift successfully tiled hundreds of square-degrees of sky in the LVC localization regions, searching for, and identifying, possible X-ray and UV/O transients in the field. Swift made important contributions to the discovery and characterization of the kilonova AT 2017gfo, discovering the UV emission and providing the deepest X-ray upper limits in the first 24 hours after the trigger, strongly constraining the dynamics and geometry of the counterpart. Swift tiled 92% of the galaxy convolved error region down to average X-ray flux sensitivities of 10−12 erg cm−2 s−1, significantly increasing our confidence that AT 2017gfo is indeed the counterpart to GW 170817 and sGRB 170817. However, there remains significant room for improvement of Swift’s follow-up in preparation for O3. This will take the form of both revised observation strategy based on detailed analysis of the results from O2, and significant changes to Swift’s operational capabilities. These improvements are necessary both for maximizing the likelihood that Swift finds a counterpart, and minimizing the impact that follow-up activities have on other Swift science priorities. We outline areas of improvement to the observing strategy itself for optimal tiling of the LVC localization regions. We also discuss ongoing work on operational upgrades that will decrease latency in our response time, and minimize impact on pre-planned observations, while maintaining spacecraft health and safety.

scholarly journals Instrument observation strategy for a new generation of three-axis-stabilized geostationary meteorological satellites from China

2019 ◽  
Vol 8 (2) ◽  
pp. 161-175
Author(s):  
Jian Shang ◽  
Lei Yang ◽  
Pan Huang ◽  
Huizhi Yang ◽  
Chengbao Liu ◽  
...  
Keyword(s):  
Attitude Control ◽  
Mode Design ◽  
The Earth ◽  
Observation Strategy ◽  
Ground System ◽  
Image Navigation ◽  
Complicated Part ◽  
New Generation ◽  
Observation Strategies ◽  
Instrument Observation

Abstract. The Fengyun-4 (FY-4) satellite series is a new generation of geostationary meteorological satellites from China. The newly adopted three-axis-stabilized attitude-control platform can increase observation efficiency and flexibility while bringing great challenges for image navigation as well as integrated observation mode design. Considering the requirements of earth observation, navigation and calibration as well as observation flexibility, instrument observation strategies are proposed. These include the earth, the moon, stars, cold space, blackbody and diffuser observations on which the instruments' in-orbit daily observations must be based. The most complicated part is the star observation strategy, while navigation precision is dependent on in-orbit star observations. A flexible, effective, stable and automatic star observation strategy directly influences star data acquisition and navigation precision. According to the requirement of navigation, two specific star observation strategies for the two main instruments on board FY-4A were proposed to be used in the operational ground system. The strategies have been successfully used in FY-4A in-orbit tests for more than a year. Both the simulation results and in-orbit application results are given, including instrument observation strategies, star observation strategies and moon observation tasks, to demonstrate the validity of the proposed observation strategies, which lay important foundations for the instruments' daily operation.

scholarly journals Research on Aerospace Cooperative Continuation Observation Strategy for Maritime Moving Target

2016 ◽  
Vol 81 ◽  
pp. 04001
Author(s):  
Xingxing Liang ◽  
Chao Chen ◽  
Jin Li ◽  
Mingxing Zhang ◽  
Gaungquan Cheng ◽  
...  
Keyword(s):  
Moving Target ◽  
Observation Strategy
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