Wednesday, March 13, 2013

(12) Air traffic control (4/7).


A few words about radar.

There was a screen of primary radar in our office, with its antenna located on the ground in the middle of Ivanka airport*. Radio frequencies of the radar had similar properties to those of our transmitters and receivers. Consequently, it was possible to see the airplanes at most frequently used heights of 1200 to 3000 metres only to the distance of 40 to 150 kilometres. The radar’s maximum range was 400 kilometres, but as was the case of transmitters/receivers, due to its location, its practical range was severely restricted due the hilly terrain, meteorological conditions and the curvature of earth. Because of this, and the slow and ponderous communication, the radar was never used, despite being constantly at our disposal. This picture shows the display, operated by a very popular bloke Fero Lisý:
One thing on its screen was tickling my curiosity: the clouds. I was able to see clouds heavy with rain, and especially the storms, and the approaching cold fronts (only their "faces" nearest to our radar. For their depths another radar would be needed, "looking" from the side. Radars with different wavelengths would also be needed for more detailed data-gathering, with - at this time - unforeseeable and certainly useful results). Today anybody with access to internet can see the weather at any time. In those faraway days (1962) it was only us and maybe the air force. Since we were receiving weather reports and forecasts at regular intervals it was interesting to compare these with what we saw on the radar screen: the differences were amazing! The reports and forecasts were created on the basis of observations from numerous ground stations and were invariably crude and several hours behind the actual situations as we were able to observe them. Ants, and no doubt other insects, have been weather forecasters par excellence since time immemorial - I wonder what kind of "radar" is being used by them...

I tried to attract the attention of our local (Bratislava airport-based) weathermen to these phenomena. I kept inviting them for several years to sit with me in front of our radar screen – none of them came!!!** None for several years, until one day, one of the newly hatched forecasters, fresh from the university, a RnDr Dušan Podhorský, came; and not only came, but became interested! That visit, in its final results, had far-reaching consequences not only for the needs of the Hydrometeorological Office, but for the improvement of radio communication and radar coverage over the entire territory of Slovakia. None of us two had any inkling of it at the time, though…

We began discussing clouds and meteorology. I was talking from my experience as a pilot and from my several years of watching the clouds on our radar; all this information was evaluated by Dušan from his theoretical angle. As well, I told him all about my problems with disinterested, apathetic, even resentful management. In the end, we received an unexpected boost in the form of a tornado (see next chapter).

Around the time something like a tornado flattened trees in a strip some 100 metres wide and 400 metres long about a kilometre above Rača (eastern part of Bratislava), and Dušan asked if I could take him there to take some photographs. After that I took him a couple of kilometres farther along "my" new road to “my” mountain, freshly cleared of vegetation, and confided in him about my efforts to improve radio communication and radar coverage of Slovakia for the purposes of Area Air Traffic Control. Dušan mentioned that a radar located on a similar mountain could be useful for the purposes of his institution, and – without knowing at the time – that was the beginning of his carrier as the forerunner of usage of radar in meteorology.
                            
                            ***
* Primary radar emits radio waves that bounce back (and also in many random directions) from obstacles in their way (mountain, clouds, airplanes, etc.); the returning waves are captured by an antenna and processed for graphic indication on a screen;

** Of the most ardent "refusenics" I remember but two names: a professor Popálený and RnDr. Forgáč. The former was refuting my claims by claiming that it is impossible to beat precise and time-honoured ground observations with some sort of pilot's fantasies; the latter restricted himself to a sort of leg-pulling remarks, akin to the adults' treatment of little children.
In about 1963 a Zlin Z-381, equipped with some meteorological instruments, landed at Vajnory. It was brought by the (then) famous glider pilot Ladislav Háza, a Czech from Prague, I think. After admiring his at the time rare airplane (the same type on which I did my basic training a few years previously), and especially its obviously meteorological instrumentation, I mentioned to him my ideas about radars and meteorology. He laughed me off, as I recall. I think he did not understand what I was blabbering about. In 1963 I myself had no clear idea myself...
By the way, much later I discovered that this Háza was fairly high in some National Hydrometeorological Institute in Prague.
                           ***
 Attempts to improve radio coverage.
I started a campaign (1963) to re-locate our transmitters/receivers and the radar somewhere on a hill. With the help of aero club airplanes, I tested most of the Slovakian territory, from Bratislava down to somewhere Prešov-Michaľany line, in low and medium altitudes, recording radio reception of Area ATC and local towers' ATC. The only airplane in Vajnory with a suitable transmitter/receiver was one Meta-Sokol. Its equipment was of poor quality, the airplane was not always available to me, so it took me around two years to get to the point where I was satisfied with the amount and quality of my data. The last and most niggling blanks on my radio-coverage maps were filled during one flight with Pal'o Veslár from Senica somewhere to the mountainous area of central Slovakia and back.

After those two years I concentrated on two mountains in the Malé Karpaty range near Bratislava, named Malý and Veľký Javorník. These two were not the ideal mountains from the radio coverage point of view as 2/3rds of its coverage would be above the neighbouring countries (I would have much preferred Inovec, near Trenčín, for example), but these two mountains were ideal from practical point of view. I lived nearby (in Rača), and was able to study them in more detail. From my recent land surveying days, I was able to wangle a couple of detailed maps (1:10,000, top secret in those days), and use them for detailed evaluation. On a few occasions I „borrowed“ an all-terrain vehicle „Gazik“ from Ivanka airport, with a small low power transmitter/receiver PYE on board, which was used for communication on the ground. With this equipment, and from „my“ mountains, I was able to communicate with airplanes flying at low levels (1800 metres) from Bratislava almost to Košice (300 kilometres away!), loud and clear!  For comparison, our official, and far more powerful, equipment could not reach airplanes above Sliač, which is but 150 kilometres away from Bratislava.

To my surprise, our management was not interested in this information in the slightest. On quite a few occasions I was summoned to the airport’s State Security office (StB), where I was threatened with various unpleasant sanctions if I do not cease my anti-management activities???!!! Often I had no idea where is the Security getting information about me from. Many years later I discovered in the so-called Petr Cibulka lists how many of my colleagues, even friends, be they at my work, or in the aero club, were agents or at least confidantes of the State Security.

I did not cease my „anti-management“ activities, though, only began to work more quietly, almost clandestinely. For that reason I was never bold enough to confide in our colleagues in the Czech half of Czechoslovakia, whose problems were no doubt similar to ours (but who, in the person of Jindra Černohorský had far more skilful operator than us in Slovakia, and they were closer to the seat of power in Prague).

***
Recently I discovered the following information. The articles inform on the activity in (my!?) meteorological radar centre after it was commissioned in 1972. Alas, I have no information on the performance of the Air traffic Control radar centre that was built at the same time:

https://journal.geo.sav.sk/cgg/article/view/107/102

.

 3. Conclusions (from the Journal above).

Listed quarter of a century has been extremely successful thanks to enthusiasm of the first team of ‘musketeers’ on the crest of Malé Karpaty, which since 1977 has been gradually enriched with qualified programmers, electrical engineers and IT specialists, making it a total of 112 members. Close cooperation between RCRM and several universities in the Czech Republic and Slovakia resulted in a number of master and doctoral theses led by the staff at Malý Javorník. These were years filled with numerous professional internships for students and professionals, supported financially by the World Meteorological Organisation, FAO, IAHS, ESA, CMEA, COSPAR and INTERKOSMOS.

Note.

In 2022, I have come across information about Sir Robert Watson-Watt, a British meteorologist, who in the 19twenties studied radio waves generated by lightnings. His observations led eventually to realization that radio waves bounce off stationary, and eventually even from moving objects (1935, some 25 years before me).

It is remarkable that in the 1960-ties, two professors of meteorology in Czechoslovakia were not aware of the Sir R.W-W's work! He, for his work, was gradually promoted to the position of Overseer of all radars in the UK; as for myself, I was being laughed at, denied any progress at work, I was accused of "undermining the achievements of socialism" and eventually threatened with jail...

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