排序方式: 共有4条查询结果,搜索用时 15 毫秒
1
1.
G. Szejwach T.N. Sletten A.F. Hasler 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1982,2(6):161-164
The feasibility of determining cirrus “emissivity” from combined stereoscopic and infrared satellite observations in conjunction with radiosounding data is investigated for a particular case study. Simultaneous visible images obtained during SESAME-1979 from two geosynchronous GOES meteorological satellites were processed on the NASA/Goddard interactive system (AOIPS) and were used to determine the stereo cloud top height ZC as described by Hasler [1]. Iso-contours of radiances were outlined on the corresponding infrared image. Total brightness temperature TB and ground surface brightness temperature TS were inferred from the radiances. The special SESAME network of radiosoundings was used to determine the cloud top temperature TCLD at the level defined by ZC. The “effective cirrus emissivity” NE where N is the fractional cirrus cloudiness and E is the emissivity in a GOES infrared picture element of about 10 km × 10 km is then computed from TB, TS and TCLD. 相似文献
2.
A.F. Hasler R. Mack A. Negri 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1982,2(6):105-113
The capability of making stereoscopic observations of clouds from meteorological satellites is a new basic analysis tool with a broad spectrum of applications. Stereoscopic observations from satellites were first made using the early vidicon tube weather satellites (e.g., Ondrejka and Conover [1]). However, the only high quality meteorological stereoscopy from low orbit has been done from Apollo and Skylab, (e.g., Shenk [2] and Black [3], [4]). Stereoscopy from geosynchronous satellites was proposed by Shenk [5] and Bristor and Pichel [6] in 1974 which allowed Minzner [7] to demonstrate the first quantitative cloud height analysis. In 1978 Bryson [8] and desJardins [9] independently developed digital processing techniques to remap stereo images which made possible precision height measurement and spectacular display of stereograms (Hasler [10], and Hasler [11]). In 1980 the Japanese Geosynchronous Satellite (GMS) and the U.S. GOES-West satellite were synchronized to obtain stereo over the central Pacific as described by Fujita and Dodge [12] and in this paper. Recently the authors have remapped images from a Low Earth Orbiter (LEO) to the coordinate system of a Geosynchronous Earth Orbiter (GEO) and obtained stereoscopic cloud height measurements which promise to have quality comparable to previous all GEO stereo. It has also been determined that the north-south imaging scan rate of some GEOs can be slowed or reversed. Therefore the feasibility of obtaining stereoscopic observations world wide from combinations of operational GEO and LEO satellites has been demonstrated.Stereoscopy from satellites has many advantages over infrared techniques for the observation of cloud structure because it depends only on basic geometric relationships. Digital remapping of GEO and LEO satellite images is imperative for precision stereo height measurement and high quality displays because of the curvature of the earth and the large angular separation of the two satellites. A general solution for accurate height computation depends on precise navigation of the two satellites. Validation of the geosynchronous satellite stereo using high altitude mountain lakes and vertically pointing aircraft lidar leads to a height accuracy estimate of ± 500 m for typical clouds which have been studied. Applications of the satellite stereo include: 1) cloud top and base height measurements, 2) cloud-wind height assignment, 3) vertical motion estimates for convective clouds (Mack [13], [14]), 4) temperature vs. height measurements when stereo is used together with infrared observations and 5) cloud emissivity measurements when stereo, infrared and temperature sounding are used together (see Szejwach [15]).When true satellite stereo image pairs are not available, synthetic stereo may be generated. The combination of multispectral satellite data using computer produced stereo image pairs is a dramatic example of synthetic stereoscopic display. The classic case uses the combination of infrared and visible data as first demonstrated by Pichel [16]. Hasler [17], Mosher and Young [18] and Lorenz [19], have expanded this concept to display many channels of data from various radiometers as well as real and simulated data fields.A future system of stereoscopic satellites would be comprised of both low orbiters (as suggested by Lorenz and Schmidt [20], [19]) and a global system of geosynchronous satellites. The low earth orbiters would provide stereo coverage day and night and include the poles. An optimum global system of stereoscopic geosynchronous satellites would require international standarization of scan rate and direction, and scan times (synchronization) and resolution of at least 1 km in all imaging channels. A stereoscopic satellite system as suggested here would make an extremely important contribution to the understanding and prediction of the atmosphere. 相似文献
3.
4.
R. Mack A.F. Hasler E.B. Rodgers 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1982,2(6):143-151
Results are presented to show the application of GOES stereoscopy to the study of hurricanes and tornadic thunderstorms. Stereoscopic cloud top height contour maps were constructed to observe the structural evolution of two hurricanes: Frederic, 12 September 1979 and Allen, 8 August 1980 and a tornadic thunderstorm complex over Oklahoma on 2–3 May 1979. Stereoscopic height contours of Hurricane Allen show a very intense and symmetric storm with a circular shaped Central Dense Overcast (CDO) with an average height of 16.5 km. Height contours of Hurricane Frederic show a preferred region for convection with an explosive exhaust tower reaching a maximum height of 17.8 km. A technique for estimating tropical cyclone intensity using GOES stereoscopic height and infrared temperature information is also presented. Utilizing short interval (3-min) GOES stereoscopic data from 2 May 1979 and 9 May 1979 (SESAME days), cloud top ascent rates were measured and used in determining the intensity of growing convective cells. Results show vertical motions ranging from 4.4 m s?1 for a moderate storm to 7.7 m s?1 for an intense storm. These results compare well in magnitude with growth rates determined from simultaneous GOES infrared observations and previous estimates of visual and radar echo top growth rates of other thunderstorms. 相似文献
1