meeting summary Report from the International Workshop on Remote Sensing in Geophysics Using Doppler Techniques* Arnaldo Brandolini,a+ Ben B. Balsley,b# Antonio Mabres,c# Ronald F. Woodman,d# Carlo Capsoni,3 Michele D'Amico,3 Warner L. Ecklund,e Tor Hagfors/ Robert Harper^ Malcolm L. Heron,h Wayne K. Hocking; Markku S. Lehtinen; Jurgen Rottger,k Martin F. Sarango,d Torn Sato,1 Richard J. Stauch,m J. M. Vaughn," Lucy R. Wyatt,0 and Dusan S. Zrnic? 1. Introduction (A. Brandolini, B. Balsley, in different application areas of Doppler remote sens- A. Mabres, R. Woodman) ing. Actually, Doppler remote sensing is employed in a wide range of applications, from atmospheric bound- The International Workshop on Remote Sensing in ary layer sensing to wind profiling, from sea surface Geophysics Using Doppler Techniques was held on 11- sensing to radar astronomy. Such different applications 15 March 1996 in Bellagio, Italy, at the Rockefeller face different challenges, which sometimes lead to Study and Conference Center. Supported by the development of very different techniques. Rockefeller Foundation, the workshop brought to- In the organizers' opinion, a discussion of such gether a small number of expert researchers working techniques between researchers working in different application areas could be both interesting and useful. *Organized by the Department of Electrical Engineering of In particular, ideas of signal-processing techniques Politecnico di Milano. could be profitably exchanged. The purpose of the +Workshop organizing committee. workshop was in fact to provide a forum where such aPolitecnico di Milano, Milan, Italy. a discussion could take place. bUniversity of Colorado at Boulder, Boulder, Colorado. The following are summeries of communications cUniversidad de Piura, Piura, Peru. given at the workshop, many of which have been up- dJicamarca Radio Observatory, Lima, Peru. eAeronomy Laboratory, National Oceanographic and Atmo- dated to account for later results. The range of topics spheric Administration, Boulder, Colorado. is indeed wide. We hope readers will find them as 'Max-Planck-Institut fur Aeronomie, Katlenburg-Lindau, Ger- stimulating and thought provoking as the workshop many. participants did. 8Amoco Corp., Houston, Texas. hJames Cook University of North Queensland, Townsville, Queensland, Australia. (B. Balsley) 'University of Western Ontario, London, Ontario, Canada. 2. Who was Doppler? jSodankyla Geophysical Observatory, Sodankyla, Finland. kEISCAT Scientific Association, Kiruna, Sweden. Because of the nature of this conference on geo- 'Kyoto University, Kyoto, Japan. physical remote sensing, it is perhaps fitting that we •"National Oceanographic and Atmospheric Administration En- vironmental Research Laboratory, Boulder, Colorado. pause briefly to reflect on the origin of the word "Defense Research Center, St. Malvern, United Kingdom. "Doppler." This statement is particularly true in view °University of Sheffield, Sheffield, United Kingdom. of the nearly generic use of the word Doppler in pNational Oceanographic and Atmospheric Administration/Na- myriad aspects of our everyday life. Who was the per- tional Severe Storm Laboratory, Norman, Oklahoma. son named Christian Doppler? When and where did Corresponding author address: Prof. Arnaldo Brandolini, he live? What did he do? And in what scientific disci- Dipartimento di Elettrotecnica, Politecnico di Milano, Piazza Leonardo da Vinci 32,1-20133 Milano, Italy. pline did he work? Many of us may have heard at some E-Mail: [email protected] point in the dim past that the Doppler effect was first In final form 3 November 1997. introduced to account for the varying colors (e.g., "blue ©1998 American Meteorological Society shifting" and "red shifting") of the stars in our night Bulletin of the American Meteorological Society 6 643 Unauthenticated | Downloaded 10/10/21 02:46 AM UTC skies. Others may be more familiar with the Doppler fact, that he and his brother sought passage to America effect of a passing train, where the high, penetrating in 1834-35. sound of the approaching train whistle changes to an Fortunately, prior to their departure to America, increasingly lower tone as the train passes. In addition, Doppler received and accepted an offer to teach at the our local TV stations often promote the fact that they State Secondary School in Prague. He subsequently are making use of Doppler weather radar. To associ- married and began a slow climb to semisecurity, even- ate these and many other phenomena with one person's tually being appointed to a full professorship at the name is singular at the very least. Thus, in this initial Prague Technical Institute in 1841. In these years he presentation of a conference wherein we will discuss became interested in "optics, astronomy, electricity, some geophysical consequences of the Doppler effect, geophysics, and undulations." He was elected a full it is timely to pause for a moment and examine the man member of the Royal Bohemian Society in 1843, fol- behind the name. lowing a presentation to that body of a landmark pa- The following paragraphs summarize the salient per "On the Coloured Light of the Double Stars and features of the life and times of the person whose name Certain Other Stars in the Heavens." There were six is coupled inextricably with the above-mentioned people present at the reading of Doppler's paper at the phenomena: Christian Andreas Doppler. Unabashed society's monthly meeting. One of these was the min- reference is made to an excellent text published in utes keeper. 1992 by Springer-Verlag: The Search for Christian In his book, Eden cites a somewhat humorous ex- Doppler, by Alec Eden (Eden 1992). Dr. Eden, ample of testing the Doppler principle that occurred incidentally, is a surgeon who makes use of the in Holland in 1845. At that time, Buys Ballot—a Doppler principle in his work in transcranial Doppler young Dutch Ph.D. who was attempting to disprove sonography. It happens that the lion's share of devel- Doppler's idea—hired a group of highly trained lo- opment of the Doppler technique—at least judging cal musicians and a locomotive flat car. He put the from the citation indices—has taken place in medicine. horn players on the station platform while he and the This area is a giant step removed from the geophysical remaining musicians were stationed on the flat car. processes with which we are concerned in this confer- The flat car with its load of musicians was set to pass ence. It is also an insight into the breadth of the tech- by the station at a prearranged 40 mph while the mu- nology that has profited by employing this principle. sicians on the station platform played a single tone. Christian Doppler was born in Salzburg, Austria, As they approached the platform the flat-car-based in 1803 and died in Venice, Italy, in 1853. He was the musicians could clearly detect a half-tone increase in son of a stonemason in a long line of stonemasons. the pitch emitted by the instruments. A correspond- Many pieces of stonework bearing the "Doppler" in- ing half-tone decrease was heard as the train receded scription can still be found around Salzburg. But cer- from the platform. This was precisely the effect pre- tainly none of these represents the efforts of Christian dicted by Doppler, much to the chagrin of Ballot. Andreas himself, since he was early recognized as In any event, only some two years following his being too frail for the demanding tasks of that profes- election to the Royal Bohemian Society, Doppler was sion. His weakness, which was in large part respira- relieved of his official duties at the Prague Polytech- tory, may have arisen as a result of breathing the nic. His heavy student load coupled with his advanced marble dust that is an inherent concomitant of the respiratory problems made it impossible for him to trade. Christian was apprenticed briefly in 1821 as a continue his teaching schedule. The final eight years "commercial apprentice," but soon found his way to of his life, between 1845 and 1853, saw his appoint- the Vienna Polytechnic Institute (1822-25) where he ment to increasingly more prestigious positions. These excelled in the sciences. He soon returned to Salzburg advancements began with his appointment as profes- (1825-29) to broaden his education, learning French, sor of mathematics, physics, and mechanics at the Italian, and English. He also wrote a bit of prose and Schemnitz Academy of Mining and Forestry (1847). poetry and authored a short scientific work on the hu- This honor was followed by being named as profes- man eye. The following period (1829-33) found him sor at the Imperial University of Vienna (1849), and again in Vienna with an assistantship at the Vienna finally as the first director of the Institute of Physics Polytechnic. Unfortunately, the combined problems of at the same institution in 1850. health, teaching, and trying to find a permanent posi- Christian Doppler's last few months were spent in tion left him desolate and depressed; so depressed, in Italy accompanied by a friend and colleague. Although 644 Vol. 79, No. 4, April 1998 Unauthenticated | Downloaded 10/10/21 02:46 AM UTC he was buried on the Island of St. Michael near Venice, time interval between one pulse and the next is com- the exact burial site is unknown. puted, and the relevant position updated. The radar simulator was applied to study improve- ments of rain rate estimates by using Doppler spec- 3. Meteorological radar simulation tral moments in a vertically pointing antenna mode. (C. Capsoni and M. D'Amico) One (Z) or two (Z and V ) moments were supplied to the inversion algorithm and a gamma drop-size distri- This contribution presented a physically based bution (DSD) was assumed; the best estimate is ob- multiparameter radar simulator that is able to gener- tained for a generic exponential DSD.