Comments & Analyses


Subject: March 22, 1957; Rectangular Targets, Long Beach/Los Angeles, CA

Date: Thu, 09 Jul 2009 16:16:18 -0400
From: Joel Carpenter <crediblesport@gmail.com>
This doesn't make much sense. It only traveled 30 miles at 3600 mph
which means the track was only 30 seconds long. I don't know what the
antenna rotation rate was, but it couldn't have been more than a few
rotations over such a short period.
Also, by 1957 I think the danger of these kind of reports being due to
ECM testing gets very high. Especially in THAT area.

Date: Thu, 09 Jul 2009 16:18:50 -0500
From: Francis Ridge <nicap@insightbb.com>
Joel,
According to Dan's report (Brad's BBU listing was about a half line but he listed it as BBU) the incident had stops and starts and lasted about 12 minutes before (a possible EMF?) something knocked out the radar. I haven't looked at the BB docs yet so we might do that before we change anything. Many times we have an interesting BB sighting we look for docs on, or we have docs we found and file them with the appropriate incident, BBU or otherwise. Then we assume we are close to being done with the case dir and pitch it out for comment. This is one that may need a little more study but the docs pretty much back the description we posted and hopefully clarify some of the issues.

Date: Thu, 09 Jul 2009 23:08:10 +0100
From: Martin Shough <parcellular@btinternet.com>
The total duration is given as 40 secs, which as Joel says can only be a few sweeps. Radar type not stated, but apparently airfield radar with max range in the region of 50 miles, which indicates airfield surveillance radar something like a CPN-4, probably 15 rpm, so maybe 10 sweeps in total.
The blip(s) moved out, then back in, finally back out to max range all on the same 320 bearing. This fixed relationship to the same group of trace radii is symptomatic of a radar intrernal fault or interference in my opinion.
The same can be said of the "rectangular" scope presentation, which was "same size" as a normal target. This can only mean the same angular width as a a typical point-target arc (the angular beam width, maybe 1-2degs) but larger on the range dimension so that a sector of the scope a degree or two wide is "filled in" with a block of excitation a similar degree-or-two deep, so roughly rectangular. This sounds like noise to me, not any kind of echo.
The 2 F-89s found nothing, consistent with a radar fault.
The clincher is the fact that the radar failed 11 minutes after the first "UFO" appeared due to an apparent voltage fault.
So, no, I don't think this one is very interesting, except educationally.

Date: Thu, 09 Jul 2009 21:25:19 -0400 (EDT)
From: Brad Sparks
I would agree with Joel, it's pretty short in duration.  i would guess the airport surveillance radar had a rotation period of 10 seconds, thus accounting for the even numbers of time intervals in 10's.  If so, then there would have been 4 blips separated by 10 seconds.  And I would guess the AF ADC reporting officer and CAA tower radar operator made a mistake in counting up the total duration, because as I reconstruct it there was a 30 second period of rapid motion, then one 10-second stop then a restart going 10 miles in reverse direction in 10 seconds then a 2nd stop for a 10-sec sweep, then reversed direction going 20 miles in presumably 20 seconds for a total duration of 70 seconds not 40 seconds.
Also, while the report talks about a 320 Mag heading, in fact the blip appeared at azimuth 300 Mag and disappeared at 315 Mag, so the heading must not have been exactly 320 Mag, it must have CURVED slightly.  The fact the motion was radial and only on one side of the radar scope and veers off slightly from directly radial into and out of the station is suggestive of mutual interference with another radar at almost exactly the same frequency.  Two blips in trail might support the interference explanation.
I am confused as to whether the CAA radar was at LAX or Long Beach or whether at that time Long Beach airport was considered some kind of satellite facility under the control of LAX ??
I think it is unthinkable that anyone in their right mind would test ECM in a densely populated area like LA and risk an airliner crash or some other disaster.

Date: Fri, 10 Jul 2009 05:51:27 -0500
From: Brad Sparks
I made a mistake and the duration is even longer.  In going over the sequence of events in the terse AFR 200-2 report I see that after the first stop the target came back towards the radar TO 10 miles range NOT BY 10 miles traveled (as I had misread it).  That means this would be 30 seconds of rapid motion going 30 miles NOT 10 miles in 10 secs.  Then stopped 10 secs.  Then 40 miles outward again in 40 secs for a total duration of 120 seconds!  Sorry about that.

Date: Thu, 09 Jul 2009 21:55:41 -0400
From: Joel Carpenter <crediblesport@gmail.com>
OK, I retract the _deliberate_ ECM idea, but surely considering the
state of the art of the electronic equipment we're talking about, and
the electromagnetic environment in that area, it's possible that there
were other microwave devices that could have caused interference.
Ships at sea, aircraft, ground systems -- LA's a big, busy place full
of defense contractors and military activity.
I guess they would have ruled that out but...

Date: Thu, 09 Jul 2009 22:05:07 -0400 (EDT)
From: Brad Sparks
Copy that.  It almost seems like someone at this other presumed interfering radar site was jiggling a PRF (pulse repetition frequency) control ever so slightly so that sometimes the pulse on the CAA radar (that he didn't know was getting interference) headed in towards the CAA antenna, sometimes stopped, sometimes headed away. 

I guess they would have ruled that out but...

B:  If there was nothing further in the file then we don't really know how much if any investigation was undertaken to identify inteference radars or even if they thought of it (though surely any radar expert would have).

Date: Fri, 10 Jul 2009 10:41:08 +0100
From: Martin Shough <parcellular@btinternet.com>
Hi Brad,
Thanks for your comments on this one. I didn't notice that Joel's reply was a 'private' one to you, me and Fran, so responded last night (below FYI) via Fran's message to the 'list' - which you are apparently not included in. Why not, BTW?
We generally I agree, I think. I did notice the figures in the body of the report differing from the "320" summary as you mention but didn't have time to get into that. The sequence of bearings and the 320 "headline" figure don't collectively make sense to me. In any case, the essentially radial to and fro motion (initially in and out on the same bearing then out again on another radius rotated a few degrees) is very suggestive of interference/internal noise, as is the presentation (I was tired and mis-wrote "triangular" for "rectangular").
The speed clocked "initially" of "approximately 3600mph" could be timed over the whole 30 mile outward leg, although this is not clear and could refer to just an "initial" displacement measured off the screen between the first two blips. If the former it could be 4 paints in 30 secs at 6 RPM. But I don't see any trend of reference to multiples of 10 secs. I see "40 SECS" in one place, which you interpret as 4 x 10 secs but which could equally be 10 x 4 secs, fitting 15 RPM, which would IMO be more likely for a busy 50-mile airfield surveillance radar than 6 RPM.
The "stops" would then be a minimum of 4 sec. Assuming a constant 3600mph this leads to 30 + 4 + 30 + 4 + [significantly] 40 secs = 108 sec as opposed to 120 secs, but this is immaterial since we can't get a total of "40 sec" in any case.
I suspect the explanation here could be that the 40 sec timed for the final outbound track has been put against question 2.f ("length of time in sight") mistakenly because it follows 2.e ("manner of disappearance") with the answer "out of radar range". Just sloppy.