Date: Thu, 13 Aug 2009 13:20:15 +0100
From: Martin Shough <>
Subject: Re: Trindade upgraded to RADCAT

Can we justify carrying this as a radar case? I don't see the evidence, myself. FYI below is the section from the site concerning the radar issue (responding to a criticism of Barauna by Tim Printy)
With regard to the radar target that Barauna first mentions in the informal Hynek interview of 1982, I agree with Printy that this was very likely a confused memory of the radar target reported the day prior to the UFO incident. As I pointed out to Kentaro Mori in advancing the same suggestion (email, 27 January 2004) the time that Barauna recalls - about 15 minutes before the UFO sighting, i.e., around noon - is in this case accurate, except that he has mentally shifted the event by 24 hours. Slightly different versions of this radar story appeared in the papers O Jornal and O Diario on day-one of the publicity on 21 Feb. In neither case is it clear where the story comes from, although in both cases radar operators are said to have dismissed the echo as a probable malfunction.

"On the eve of the sighting, i.e., on January 15th, the saucer had been detected by the ship’s radar, also about noon.  The men in charge of the device thought the radar was out of order and made a through check to ascertain whether it was working properly." 0 Diário de São Paulo, São Paulo, February 21, 1958 (cited by Simoes)

"The day before the sighting, approximately at the same hour, the flying saucer had been spotted by the ship’s radar. But radar operators thought that strange 'blip' was caused by some kind of trouble in the apparatus—and rechecked it to see if it was operating properly." O Jornal, Feb 21 (cited by Fontes)

Barauna himself is first quoted as recalling this incident in an interview published in O Cruzeiro March 8 1958. He explicitly says that he was informed by the Navy about the four other visual sightings reported over the island, then appears to add the radar story as an afterthought. He may well have picked this up from newspaper reports. In this early statement, however, he still correctly recalls the date as Jan 15.

These radar stories appear in the papers on the same day that Barauna is quoted by Ultima Hora as saying that the Almirante Saldanha had not detected 'his' object on radar because the radar wasn't able to be manned in time. This could be interpreted as being in conflict with his statement 24 years later that the radar set was somehow disabled. But could he really be expected to know any of these things with authority? If he was extemporising in 1958, and/or embellishing a confused memory in 1982, are these things suspicious? Or merely human?

Now of course Barauna was not a Navy man, still less a radar operator. And let's remember that all these statements are just hearsay, often third-hand by the time we read them, with ambiguities and inaccuracies in the printed story to be considered as well. Portable voice recording was a pretty esoteric business in 1958 and the usual technological solution would be pencil and short-hand, Q & A being "reconstructed" - usually with a little extra journalistic flavour - back in the office (or in the local bar!). So, yes there may be material contradictions here, or there may not. Barauna might well have been making up reasons why there was no radar report. Another name for this would be speculating. Reporters enjoy printing speculations as facts.

There's no reason to expect that Barauna would be reliably informed about everything. Why shouldn't he give a few foggy answers in the face of persistent questioning? He was on board only as an invited civilian. His first-hand experience was limited to taking the photos and then being part-involved with the Navy tests of the negatives. He heard some things from Bacellar and others during the tests, yes, but he was never a Navy 'insider'. He probably listened to rumours and read the papers like anybody else. In fact we know he did - according to Zaluar he'd kept a scrap-book of news cuttings. He probably rounded out his picture of what happened by absorbing both information and misinformation from such sources, like anyone else.

The presumption would be that Barauna had heard tell from Navy sources that there was no radar confirmation. But maybe he didn't know exactly why. Why should he? When asked by a reporter on Day 1 of the publicity he was pressed on this and suggested reasonably that it was all over too quickly, that the radar was not switched on and warmed up, or was not manned - which all amounts to the same thing. (The bit of picture-painting in Ultima Hora about the operator "running" to get to the radar is not very material.) Later he maybe put two and two together, and guessed from hearing of the Navy's concerns about compasses, radars and motors that the radar must have been affected. If Barauna was genuine, indeed, then this is a very natural interpretation. It isn't hard to imagine that as the years went by this notion got conflated with his 'memory' of a stalled boat-winch etc.

Alternatively we can conclude that Barauna knew perfectly well that there could have been no radar contact because the whole thing was a hoax, and he decided to "explain" this away by inventing the story that the ship's radar wasn't operating. But what if the radar really _was_ operating? A lot of people were in a position to know about that, not least the Navy. If the radar was working, then seeing Barauna telling lies to the papers on the first day would have instantly tipped off the Navy that he was pulling a stunt. He couldn't have made this story a part of his hoax successfully unless he knew that the radar in fact was not working (for whatever reason), in which case it was simply the truth and so gets us nowhere.

As for the nature of the echoes reported (whichever day this may have happened) there is almost nothing to be said. There is no information at all. Printy is mistaken, however, in his attempt to suggest that the Almirante Saldanha's marine radar would be especially unlikely to detect airborne targets.

He says:

"One must understand that a surface search radar was not specifically designed to track aircraft. Instead it was more important for it to track other ships and sea-level obstacles in poor visibility. The fact remains that existence of an actual radar type and ability can not be readily confirmed. Additionally, it seems likely that if there was a radar in operation, it probably was not designed for tracking aircraft."

The version of this incident quoted by Printy (from Fontes) has it that the operator attempted to engage the radar's automatic tracking mode but failed. Printy may have been encouraged by this to believe that the radar concerned was not simply a marine navigation radar but a more sophisticated gyro-stabilised combat radar. However the newspaper accounts describing the episode (see above) do not contain any mention of automatic tracking and Fontes gives no attribution for his version. Printy goes on to assert that the ship's radar would probably have a horizontal beamwidth of 2 - 4 degrees and a very narrow vertical beamwidth of only 1 - 2 degrees, so that only a very low-flying aircraft would have a slim chance of briefly entering the coverage. This conclusion appears to be a misunderstanding.

The primary requirement for radar on a ship is for navigation. If a ship has one scanner then it is likely to be a marine navigation radar. Detailed scaled deck plans of the Almirante Saldanha show a single radar scanner on a tripod mounting at a height of about 30' above the deckhouse roof (about 65' above the waterline). This appears to be a single-curvature, tilted-parabolic design typical of a basic marine navigation scanner (Fig.1). Such a marine surveillance radar has exactly the same principal design goals as an air surveillance radar, that is to say good azimuth discrimination allied with good range discrimination (which is dependent on pulse length and is not relevant here) and a coverage pattern that is as far as possible gap-free. To achieve this the beam has a fan shape which is narrow in azimuth and very broad in elevation.

A shallow vertical coverage of the sort described by Printy would be useless on a ship where the sea surface has to be illuminated from close range out to the horizon even though the ship might be pitching and rolling by many degrees in a heavy sea. All surveillance radar emissions - marine or air - intersect the surface at all ranges from very close to the antenna out to the radar horizon. (It is precisely by managing the constructive/destructive interference of reflected wavefronts from the surface that the designer generates the desired beam shape.) The vertical diagrams for typical marine radars of this vintage will be between 15 and 30 degrees with scan rates of around 2 to 4 seconds, which makes them comparable to many air surveillance designs and fully capable of displaying aircraft over a very large range of altitudes.

Fig.1. Radar scanner and tripod, elevations.
Approximately to scale, adapted from deck plans by Harold A. Underhill A.M.I.E.S

The tilted-parabolic reflector shown (this is a slightly more efficient arrangement than the basic 'cheese' antenna because the feed horn structure can be kept out of the beam) has an aperture of about 10 feet by 2 feet. The beamwidth (taken as the angle between the 3dB-down or half-power points) is dependent on the number of wavelengths in the aperture, like

1.22 rad (l/aperture)

which for a 10cm radar - a common marine wavelength - gives a horizontal beamwidth of about 2.3 degrees and a vertical of about 15 degrees, consistent with typical marine navigation scanners. (These are obviously very gross approximations based on guesswork and the detailed specifications of the actual radar are needed.)

In some more sophisticated surface-search radars the scanner head is gyro-stabilised which would allow radar energy to be concentrated in a narrower vertical beam width. Such radars were in military use in 1958, but the absence of more than a basic marine navigation scanner on the Almirante Saldanha is consistent with the history and contemporary role of the ship, and with the fact that no radar upgrade was made during the ship's partial refit from a school ship to a hydrographic survey vessel in 1957.

According to the list of electronics acquisitions in the Brazilian Navy General Index for 1957 new radars were installed on several military vessels in that year, mainly SPS-4 and SPS-6. This new suite introduced a distinction between surface and air search in that different frequencies were used (C and L band respectively) and the surface-search SPS-4 could be gyro-stabilised against roll (it could also be modified to fill the gap in the SPS-6 air-search cover, i.e. rotated for "zenith search"). But the Navy Index lists only an AN/UQN-1C echo bathymeter for the Almirante Saldanha - no new radar. This points up the fact that she was not a frontline combat ship, but a 4-masted sailing vessel hitherto used for training and now (as of August 1957) seconded to the Hydrographic Division.

In conclusion, the radar anomaly reported on Jan 15 is unevaluable. It could presumably have been one of the events that motivated the Navy Intelligence report to recommend the reporting of radar effects in future UFO cases, and this could be true whether it was construed as a genuine target or as a malfunction. However, none of the above issues has any direct relevance to Barauna's testimony - except insofar as the coincidence of a radar 'UFO' occurring the day before the Jan 16 sighting does bear on the probability of a photo hoax that had to have been pre-planned before the ship sailed (see later)