Minimum effective area for high resolution crater counting of martian terrains

Icarus ◽  
2015 ◽  
Vol 245 ◽  
pp. 198-240 ◽  
Author(s):  
Nicholas H. Warner ◽  
Sanjeev Gupta ◽  
Fred Calef ◽  
Peter Grindrod ◽  
Nathan Boll ◽  
...  
2000 ◽  
Author(s):  
Daniel A. Schwartz ◽  
Laurence P. David ◽  
R. H. Donnelly ◽  
Richard J. Edgar ◽  
Terrance J. Gaetz ◽  
...  

Author(s):  
Kevin W. Ferguson

With the age of the original Panhandle Eastern Pipeline (PEPL) Company pipelines, it’s not a matter of if anomalies will be found when an ILI tool is run, it’s a matter of how many and how severe. When a final report is received from an ILI vendor, burst pressures are typically calculated using Modified B31G, 0.85dL. The results can seem unmanageable, but success has been had doing further assessments on some anomalies without excavating them all. This assessment has been developed and performed by PEPL on three sets of Tuboscope ILI data and one set of Baker Hughes CPIG data. The method to be discussed was first employed in 2002. It provides a more accurate characterization of the defect and provides the company the ability to more effectively allocate resources. Efforts have been made to review the color scan of a vendor’s raw High Resolution Magnetic Flux Leakage (HRMFL) data, and perform an assessment using Effective Area Analysis without excavating hundreds of anomalies that prove no threat to the pipeline. This assessment is done by hand on the computer and in many cases returns a burst pressure higher than that calculated using Modified B31G, 0.85dL. The following is a case study that shows how multiple defects have been assessed prior to excavation in an attempt to more accurately characterize the defect, and allow for a better allocation of resources. Digs have been performed to validate the process, and the results will be discussed.


2005 ◽  
Vol 13 ◽  
pp. 796-798
Author(s):  
M Kowalski

AbstractAPEX is a proposed Small Explorer satellite that will obtain high-resolution EUV spectra of white dwarfs, CVs, stellar coronae, and the local ISM. The APEX effective area (30-50 cm2) and resolution (~10,000) are an order of magnitude improvement over Chandra.


Author(s):  
Patrick Viltart ◽  
Franc¸ois Jacquiot

Trapil is Europe’s leading refined product pipeline operator, with approximately 4,700 kilometers of pipeline in three networks in France. The Le Havre-Paris network has a number of dual-diameter 10” and 123/4” seamless lines in the Paris region. Built in the 1950s and 1960s, they are now located in heavily-populated areas where excavation to assess defects or perform repairs is difficult. Best in-line inspection practice for this type of line recommends the use of ultrasonic tools because of their depth-sizing accuracy and detection capabilities. The need for a dual-diameter, high-resolution ultrasonic tool to survey six 10”–123/4” lines prompted Trapil to develop its own tool offering a variety of benefits, such as using the RSTRENG effective area method to perform fitness-for-purpose calculations prior to excavation and determining the shape of dents.


2008 ◽  
Vol 26 (10) ◽  
pp. 3169-3184 ◽  
Author(s):  
V. Delouille ◽  
P. Chainais ◽  
J.-F. Hochedez

Abstract. Future missions such as Solar Orbiter (SO), InterHelioprobe, or Solar Probe aim at approaching the Sun closer than ever before, with on board some high resolution imagers (HRI) having a subsecond cadence and a pixel area of about (80 km)2 at the Sun during perihelion. In order to guarantee their scientific success, it is necessary to evaluate if the photon counts available at these resolution and cadence will provide a sufficient signal-to-noise ratio (SNR). For example, if the inhomogeneities in the Quiet Sun emission prevail at higher resolution, one may hope to locally have more photon counts than in the case of a uniform source. It is relevant to quantify how inhomogeneous the quiet corona will be for a pixel pitch that is about 20 times smaller than in the case of SoHO/EIT, and 5 times smaller than TRACE. We perform a first step in this direction by analyzing and characterizing the spatial intermittency of Quiet Sun images thanks to a multifractal analysis. We identify the parameters that specify the scale-invariance behavior. This identification allows next to select a family of multifractal processes, namely the Compound Poisson Cascades, that can synthesize artificial images having some of the scale-invariance properties observed on the recorded images. The prevalence of self-similarity in Quiet Sun coronal images makes it relevant to study the ratio between the SNR present at SoHO/EIT images and in coarsened images. SoHO/EIT images thus play the role of "high resolution" images, whereas the "low-resolution" coarsened images are rebinned so as to simulate a smaller angular resolution and/or a larger distance to the Sun. For a fixed difference in angular resolution and in Spacecraft-Sun distance, we determine the proportion of pixels having a SNR preserved at high resolution given a particular increase in effective area. If scale-invariance continues to prevail at smaller scales, the conclusion reached with SoHO/EIT images can be transposed to the situation where the resolution is increased from SoHO/EIT to SO/HRI resolution at perihelion.


1972 ◽  
Vol 14 ◽  
pp. 740-741
Author(s):  
J. H. Parkinson ◽  
K. Evans ◽  
K. A. Pounds

New results are presented from high resolution Bragg crystal spectrometers flown in late 1970 on two Skylark rockets. The first instrument, launched on 24 November 1970 at 22 13 UT from Woomera, South Australia, contained two crystal spectrometers, each with an effective area of 50 cm2 and field collimation to 3’ FWHM. This instrument obtained the X-ray spectrum of the quiet corona in the wavelength range 5–14 Å. The second instrument was launched on 6 December 1970 at 11 13 UT from Sardinia, Italy, and contained four crystals of 6 cm2, each collimated to 4’ FWHM. This instrument was pointed at a non-flaring active region near N20 W40(McMath region 11060), and obtained an X-ray spectrum between 5 and 23 Å. This first use of a collimator to limit the field of view has considerably increased the spectral clarity compared with earlier observations by excluding the contributions of other active regions.


1990 ◽  
Vol 115 ◽  
pp. 330-334
Author(s):  
James Green ◽  
Stuart Bowyer

AbstractWe present a new design for high resolution spectroscopy from 80 to 400 Å. This design employs grazing incidence optics and variable line-spaced gratings to achieve high resolution. Unlike some previously proposed EUV echelles, this design employs straight groove planar gratings, which are a well-proven, easily manufactured design. The instrument delivers a peak resolution of λ/Δλ = 7500 and a peak effective area of 3 cm2.


1998 ◽  
Author(s):  
Daniel Patnaude ◽  
Deron O. Pease ◽  
R. H. Donnelly ◽  
Michael Juda ◽  
Christine Jones ◽  
...  

1967 ◽  
Vol 31 ◽  
pp. 45-46
Author(s):  
Carl Heiles

High-resolution 21-cm line observations in a region aroundlII= 120°,b11= +15°, have revealed four types of structure in the interstellar hydrogen: a smooth background, large sheets of density 2 atoms cm-3, clouds occurring mostly in groups, and ‘Cloudlets’ of a few solar masses and a few parsecs in size; the velocity dispersion in the Cloudlets is only 1 km/sec. Strong temperature variations in the gas are in evidence.


2019 ◽  
Vol 42 ◽  
Author(s):  
J. Alfredo Blakeley-Ruiz ◽  
Carlee S. McClintock ◽  
Ralph Lydic ◽  
Helen A. Baghdoyan ◽  
James J. Choo ◽  
...  

Abstract The Hooks et al. review of microbiota-gut-brain (MGB) literature provides a constructive criticism of the general approaches encompassing MGB research. This commentary extends their review by: (a) highlighting capabilities of advanced systems-biology “-omics” techniques for microbiome research and (b) recommending that combining these high-resolution techniques with intervention-based experimental design may be the path forward for future MGB research.


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