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Bartholic, J. F.

Publications and source records attributed to Bartholic, J. F..

14 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

A two-stage cross correlation approach to template matching

Two-stage template matching with sum of absolute differences as the similarity measure has been developed by Vanderburg and Rosenfeld (1977). This correspondence shows the development of two-stage template matching with cross correlation as the similarity measure. The threshold value of the first-stage is derived analytically and its validity is verified experimentally. Considerable speed-up over the one-stage process can be obtained by introducing only a small false dismissal probability.

Goshtasby, A.↗
NASA NTRS1983

Comparison of winter-nocturnal geostationary satellite infrared-surface temperature with shelter-height temperature in Florida

Geostationary satellite surface temperatures derived from a Visible and Infrared Spin Scan Radiometer (VISSR) sensor (10.5 to 12.6 microns) were compared with 1.5-m air temperatures collected by a thermocouple on a traversing vehicle along rural highway transects in Florida, and with two fixed thermographs located in rural and agricultural areas. Statistical comparisons between satellite and 1.5-m observations yielded a mean correlation coefficient of 0.87 and an average sample standard deviation from regression of 1.57 C during clear nights for four winters (1978-1981). The satellite-temperature image of Lake Okeechobee was compared with its geographic outline for areal image registration. Manual overlays of temporal images were repeatable to within one pixel. Satellite-sensed water temperature of Lake Okeechobee was used as an indicator of satellite radiometer repeatability and stability.

Chen, E.↗
NASA NTRS1982

Delineation of cold-prone areas using nighttime SMS/GOES thermal data Effects of soils and water

Infrared digital data from geostationary satellites were used to demonstrate the usefulness of remotely sensed surface temperature data to delineate microscale and mesoscale climates. Nocturnal winter data (December-February) from 1976-77 to 1978-79 over Florida revealed noticeable contrasts in surface temperature patterns. Colder areas were associated with low soil moisture content in the upper layers of excessively drained and well drained sandy soils, whereas warmer areas were associated with bodies of water, wetlands, or poorly drained soils. An unexpected surface temperature pattern for one night where the north-central Florida climatic zone was colder than the north Florida climatic zone was found to be caused by differences in antecedent frontal rainfall. Differences in surface radiant energy fluxes over these two areas at 0200 EST 20 December 1977, based on average satellite-sensed surface temperatures, were compared with differences in soil heat fluxes that were computed from 1.5 m climatological temperatures and soil thermal properties by use of a simplified surface energy balance equation.

Chen, E.↗
NASA NTRS1979

Emissivity correction for interpreting thermal radiation from a terrestrial surface

A general method of accounting for emissivity in making temperature determinations of graybody surfaces from radiometric data is presented. The method differs from previous treatments in that a simple blackbody calibration and graphical approach is used rather than numerical integrations which require detailed knowledge of an instrument's spectral characteristics. Also, errors caused by approximating instrumental response with the Stephan-Boltzman law rather than with an appropriately weighted Planck integral are examined. In the 8-14 micron wavelength interval, it is shown that errors are at most on the order of 3 C for the extremes of the earth's temperature and emissivity. For more practical limits, however, errors are less than 0.5 C.

Sutherland, R. A.↗
NASA NTRS1979

Satellite-sensed winter nocturnal temperature patterns of the Everglades Agricultural Area

Surface temperature patterns of drained organic soil farmland in the Everglades Agricultural Area south of Lake Okeechobee, Florida, were studied using GOES-1 satellite infrared digital data for the winters of 1976-77 and 1977-78. Local thermal features were explained in terms of soil types, soil depths and climate modification caused by organic soil drainage. A cold-prone area was delineated in the Everglades Agricultural Area with satellite data. The winter nighttime surface temperatures of this area were more characteristic of north central Florida, approximately 370 km further north, than of surrounding areas of mineral soil or undrained organic soil.

Chen, E.↗
NASA NTRS1979

Simulating the moderating effect of a lake on downwind temperatures

A steady-state, two-dimensional numerical model is used to simulate air temperatures and humidity downwind of a lake at night. Thermal effects of the lake were modelled for the case of moderate and low surface winds under the cold-air advective conditions that occur following the passage of a cold front. Surface temperatures were found to be in good agreement with observations. A comparison of model results with thermal imagery indicated the model successfully predicts the downwind distance for which thermal effects due to the lake are significant.

Bill, R. G., Jr.↗
NASA NTRS1979

Future freeze forecasting

Real time GOES thermal data acquisition, an energy balance minimum temperature prediction model and a statistical model are incorporated into a minicomputer system. These components make up the operational "Satellite Freeze Forecast System" being used to aid NOAA, NWS forecasters in developing their freeze forecasts. The general concept of the system is presented in this paper. Specific detailed aspects of the system can be found in the reference cited.

Bartholic, J. F.↗
NASA NTRS1978

Observations of the convective plume of a lake under cold-air advective conditions

Moderating effects of Lake Apopka, Florida, on downwind surface temperatures were evaluated under cold-air advective conditions. Point temperature measurements north and south of the lake and data obtained from a thermal scanner flown at 1.6 km indicate that surface temperatures directly downwind may be higher than surrounding surface temperatures by as much as 5 C under conditions of moderate winds (about 4 m/s). No substantial temperature effects were observed with surface wind speed less than 1 m/s. Fluxes of sensible and latent heat from Lake Apopka were calculated from measurements of lake temperature, net radiation, relative humidity, and air temperature above the lake. Bulk transfer coefficients and the Bowen ratio were calculated and found to be in agreement with reported data for nonadvective conditions.

Bill, R. G., Jr.↗
NASA NTRS1977

Significance of vegetation in interpreting thermal radiation from a terrestrial surface

The regions between crop rows are modeled as infinitely long diffuse cavities. Geometrical view factors are calculated, accounting for reflected radiation emanating internal to the cavity and from the background sky. A 'cavity' emissivity dependent on local geometry is defined to allow for correcting apparent temperatures to true temperatures. The total emissivity appropriate for correcting aircraft thermal data is then calculated by averaging all emissivity components to account for soil, crop, and background. It is shown that even for the lowest crop and vegetation emissivities, if the crop height-to-spacing ratio is greater than unity, the composite emissivity is greatly increased, giving rise to a decreased error in remotely sensed temperature data.

Sutherland, R. A.↗
NASA NTRS1977

Cold climate mapping using satellite high resolution thermal imagery

In an attempt to improve cold climate mapping and freeze forecasting techniques, thermal imagery from the NOAA-2 and -3 satellites and the Synchronous Meteorological Satellite (SMS) were obtained and analyzed. Enhanced image transparencies showed detailed temperature patterns over the peninsula of Florida. The analysis was superior to hand-drawn isotherms drawn from the 300 to 500 thermograph stations presently in use. Satellite data on several cold nights with similar synoptic conditions showed that similar cold patterns existed. Thus, cold climate mapping is possible.

Bartholic, J. F.↗
NASA NTRS1977

Observations of the microclimate of a lake under cold air advective conditions

The moderating effects of Lake Apopka, Florida, on downwind surface temperatures were evaluated under cold air advective conditions. Point temperature measurements north and south of the lake and data obtained from the NOAA satellite and a thermal scanner flown at 1.6 km, indicate that, under conditions of moderate winds (approximately 4m/sec), surface temperatures directly downwind may be higher than surrounding surface temperatures by as much as 5 C. With surface wind speed less than 1m/sec, no substantial temperature effects were observed. Results of this study are being used in land use planning, lake level control and in agriculture for selecting planting sites.

Bill, R. G., Jr.↗
NASA NTRS1970

Thermal scanner data for studying freeze conditions and for aiding irrigation scheduling

The use of thermal imagery in connection with plant water stress appears to hold considerable potential, particularly with scanners such as the RS-14 where internal calibration sources can be adjusted to bracket the temperatures of interest. The data from the thermal film are fairly easy to reduce; however, data reduction in 3 days or less would be required before it could be used in irrigation timing.

Bartholic, J. F.↗