00514nas a2200145 4500008004100000245007100041210006900112300001300181490000700194100001500201700001900216700001600235700001700251856010000268 1989 eng d00aMapping surface soil moisture with L-band radiometric measurements0 aMapping surface soil moisture with Lband radiometric measurement a305 -3120 v271 aWang, J.R.1 aSchmugge, T.J.1 aShiue, J.C.1 aEngman, E.T. uhttp://lter.konza.ksu.edu/content/mapping-surface-soil-moisture-l-band-radiometric-measurements01661nas a2200145 4500008004100000245009200041210006900133300001300202490000700215520113300222100001901355700001501374700001601389856011001405 1988 eng d00aResults from the push broom microwave radiometer flights over the Konza Prairie in 19850 aResults from the push broom microwave radiometer flights over th a590 -5960 v263 a

There were four flights of the NASA C-130 aircraft carrying the Push Broom Microwave Radiometer (PBMR) over the Konza Prairie Research Natural Area in eastern Kansas in 1985. Their objective was to observe surface soil moisture variations with the PBMR. The radiometer operates at the 21-cm wavelength and has four beams that sweep out a swath of about 1.2 times the aircraft altitude. The resolution of each beam is 0.3 times the altitude. At the time of the flights the soil conditions ranged from very wet to moist and the microwave emission expressed as brightness temperatures for the burned watersheds ranged from below 200 to about 245 K. The brightness temperatures were correlated (r2 = 0.5) with surface moisture measurements and the slope of the regression is in good agreement with prior results over other grasslands. However, for the unburned watersheds the brightness temperatures were around 270 K and roughly independent of the soil moisture conditions. In these unburned watersheds, a buildup of a thatch layer serves as highly emissive layer above the soil, causing high brightness, especially when wet

1 aSchmugge, T.J.1 aWang, J.R.1 aAsrar, G.A. uhttp://lter.konza.ksu.edu/content/results-push-broom-microwave-radiometer-flights-over-konza-prairie-198502477nas a2200145 4500008004100000245007400041210006900115260001800184300001300202520195400215100001902169700001902188700001602207856010802223 1987 eng d00aAirborne multispectral observations over burned and unburned prairies0 aAirborne multispectral observations over burned and unburned pra aAnn Arbor, MI a203 -2073 a

One of the ongoing studies at the Konza Prairie Natural Area (KPNA) in central Kansas is that of determining the effects periodic burning has on the native grassland ecosystem. In this study, watersheds are burned at intervals from one year to ten years or not at all. The Evapotransiration Laboratory at Kansas State University has been studying the multispectral response of burned and unburned watersheds using truck mounted raiometers and microwave scatterometers since 1983. In June 1985, there was a series of 5 flights with the NASA C-130 aircraft over the KPNA. On board the aircraft was the NS001 multispectral scanner, also known as the thematic mapper simulator. It has 7 visible and near IR channels and a thermal IR channels, whose spectral bands were chosen to simulate the thematic mapper on Landsat's 4 and 5. The 21-cm Pushbroom Microwave Radiometer (PBMR) was also on board the aircraft for soil and moisture observations. In addition several L- Band SAR images from the NASA CV-990 aircraft were obtained during this period. The spectral differences between the burned and unburned watersheds were clearly observable in all spectral bands including the thermal IR and the microwave. The normalized difference vegetation index (NDVI) using TM bands 3 and 4 was calculated. Values of less than 0.5 were obtained for the unburned watersheds which contained a mixture of senescent and green vegetaion. The NDVI values for the burned watersheds which contained only green vegetation were greater than 0.6. In the thermal IR, 3 to 4 degree Celsius temperature differences between the two treatments were observed at about 2:00 p.m. LST with the burned watersheds being cooler. Large differences between the two treatments were observed in the microwave emissivities derived from the PBMR data. These are attributed to the build-up of a layer of senescent vegetation on the soil surface in the unburned and ungrazed watersheds

1 aSchmugge, T.J.1 aKanemasu, E.T.1 aAsrar, G.A. uhttp://lter.konza.ksu.edu/content/airborne-multispectral-observations-over-burned-and-unburned-prairies01771nas a2200145 4500008004100000245009100041210006900132260001800201300001300219520123100232100001901463700001501482700001901497856010901516 1987 eng d00aResults from the pushbroom microwave radiometer flights over the Konza Prairie in 19850 aResults from the pushbroom microwave radiometer flights over the aAnn Arbor, MI a877 -8813 a

There were 4 flights in 1985 of the NASA C-130 aircraft carrying the Push Broom Microwave Radiometer (PBMR). The flights were over the Konza Prairie in central Kansas and their objective was to observe surface soil moisture variations with the PBMR. The radiometer operates at the 21-cm wavelength which is most sensitive to soil moisture. It has 4 beams which sweep out a swath of about 1.2 times the aircraft altitude. The resolution of each beam is 0.3 time the altitude. At the time of the flights the soil conditions ranged from very wet to moist and the brightness temperatures for the burned watersheds ranged from below 200 K to about 230 K. These results were well correlated (r2 = 0.7) with ground truth measurements and in good agreement with prior results over pasture grass situations. However for the unburned watersheds the brightness temperatures were around 270 K and roughly independent of the soil moisture conditions. In these unburned watersheds there is a buildup of a thatch layer which serves as highly emissive layer above the soil, especially when wet. This layer also caused a lower return to be observed over this area during this period, which is consistent with the radiometer observations

1 aSchmugge, T.J.1 aWang, J.R.1 aLawrence, R.W. uhttp://lter.konza.ksu.edu/content/results-pushbroom-microwave-radiometer-flights-over-konza-prairie-1985