Spatial coverage

The use of various statistical techniques has been discussed (46) for two situations. For standard air quality networks with an extensive period of record, analysis of residuals, visual inspection of scatter diagrams, and comparison of cumulative frequency distributions are quite useful techniques for assessing model performance. For tracer studies the spatial coverage is better, so that identification of meiximum measured concentrations during each test is more feasible. However, temporal coverage is more limited with a specific number of tests not continuous in time. 

Spatial coverage (At-Risk Volume Approach)—based on the correlation between flammable gas accumulation and the resultant overpressure upon ignition. The detection spacing is determined by estimating the size of the cloud that can present a credible escalation hazard. 

Spatial coverage is a gas detection layout methodology that utilizes a goal setting or at-risk volume approach (Bond, 1993). The objective is to detect gas accumulations that can cause catastrophic escalation through a pragmatic methodology. For flammable gas hazards, this can be based on detection of... 

Completion of Field Studies in the Troposphere with Better Spatial Coverage. All of the examples of tropospheric measurements in this chapter were made at surface sites with the instrument inlets within 4 to 10 m of the ground. With the important influences of the surface on the near-surface concentrations of some atmospheric species and the lack of spatial information from surface studies, it is important to coordinate the surface measurements with aircraft (or balloon) measurements. Some aircraft measurements of nitrogen species in the troposphere have been made, but it is important to ensure that the measurement techniques on the surface and in the air give equivalent results. This assurance can only be accomplished through careful intercomparison of instruments utilized in each platform. 

Once developed, pilotless aircraft with long flight-time capabilities will be an exciting new platform for extending spatial coverage of measurements,... 

The Southeastern United States. There are far fewer sites with sufficiently intensive data to determine their watershed N loss status in the Southeast than in the Northeast (Figure 13). The spatial coverage of sites in the Southeast with seasonal data is poor, and few sites have the long-term data needed to detect trends in N03" concentrations. 

Figure 3. (a) Spatial distribution of mean annual moist static energy. The station locations (crosses) indicate the spatial coverage of the data set. (b) Spatial distribution of the function G=T+ y, Z where T is the mean annual temperature, Z is the station elevation, and y, = 5.9 K/km. The distributions of each variable as functions of latitude are shown in the insets. [Used by permission of Geological Society of America, from Forest et al. (1999), Geol. Soc. Am. Bull., Vol. Ill, Fig. 3, p. 502.]... 

Ground-based mm-wave emission techniques have recently provided definitive identification of HO2 in the upper stratosphere, measurements which can be directly compared with previous in situ experiments [13]. Figure 8 presents those recent spectra. These observations can be used both to cross check in situ techniques, for which two have been reported, and to extend measurements of this key free radical above the maximum altitude attainable by balloons, specifically above 45 km. We thus find a critical combination of independent techniques with highly complementary temporal and spatial coverage evolving such that the vertical distribution of a key free radical will soon be established in the scientific literature. 

Our knowledge of crustal composition obviously depends on the number and spatial coverage of the available measurements. Uranium and thorium concentrations can now be determined routinely using modern techniques, and the number of data published each year is very large. Yet there are several systematic biases in the data, and these must be borne in mind. 

These data do not offer enough spatial coverage to assess the differences between eastern and noneastern rural corrosion rates. 

Fig. 3. Near-range remote sensors of the German maritime surveillance aircraft and their spatial coverage. Also shown are the SLAR as a far-range sensor, the central operating console (COC) and the forward-looking infrared imaging system (FLIR) for ship identification...

Tables 1 and 2 present typical values for the spatial, temporal and radio-metric resolutions of marine radar, airborne and satellite radar systems. The marine radar is found to provide a much reduced spatial coverage but...

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