NAAWS, an international programme aimed at developing a unified system
for fleet defence, was expected to be a major customer for the new infrared
technology. Companies in Canada, the Netherlands, France, Britain and Israel
are working on these systems and are anxiously awaiting a decision over
NAAWS which was expected this month but has been put off till September
because of the uncertain state of current arms negotations.

At the heart of the new systems lies the detection of heat signatures
from incoming aircraft or missiles. Any object moving through the air leaves
behind a characteristic heat plume, either through burning fuel or simply
through friction with the air.

Infrared sensors passively pick up these minute amounts of heat radiation.
Radar works quite differently: it emits its own microwave radiation and
detects any echoes which bounce off the target. It then calculates the location
of the enemy. Radar has a number of drawbacks: it can be jammed with electronic
noise produced by the enemy; it gives away its position to the enemy since
it emits a microwave signal; and it cannot detect objects close to the surface
of the sea or the ground.

One of the leading infrared systems currently being tested under NAAWS
is being developed by the Canadian company Spar Aerospace and is known as
AN/SAR-8.

Spar claims that its system can detect sea-skimming missiles such as
the French Exocet which sank HMS Sheffield during the Falklands War. Such
missiles evade radar by flying very close to the surface of the sea and
are only detected when they are seconds from impact. Spar’s new system may
also even be effective against the new ‘stealth’ bomber and missiles which
are almost invisible to radar. These give out heat which an infrared sensor
may be able to pick up.

Infrared systems do have drawbacks of their own. Humid weather, fog
and heavy rain hampers infrared detection. Its short range, of around 20
kilometres, limits its use to quick self-defence. S. Sankar of Raytheon
Canada, a major manufacturer of radar, says: ‘I don’t see AN/SAR-8 replacing
radar, but rather the two complementing each other.’

AN/SAR-8 is the product of a joint effort costing Canadian $150 million
(Pounds sterling 75 million) between the US Navy and the Canadian Department
of National Defence. On the deck of a ship, AN/SAR-8 consists of a telescope
which focuses the infrared radiation onto an array of solid-state sensors.
The detectors must be cooled to the temperature of liquid nitrogen to reduce
the effect of thermal ‘noise’ from surrounding equipment. The apparatus
is mounted on a rotating platform stabilised against the ship’s rolling
motion. As it scans the horizon like a silent eye looking for heat signatures,
the sensors feed signals into processor circuits which weed out background
clutter – such as birds or clouds – and enhance the image.

A computer below decks transforms these signals into an image of the
approaching enemy on a screen. From here the information is transferred
to a second computer which track the targets, transmits the data to the
other ships and aircraft in the convoy, and alerts the combat weaponry.

AN/SAR-8 first spots missiles as they drop from the aircraft. It then
tracks them all the way in, giving the ship a full minute and a half to
respond – long enough to prepare defensive weapons. The system is currently
undergoing testing at the US Navy’s Pacific Missile Test Center, near Oxnard,
California, prior to production in 1993.

An important rival to AN/SAR-8 comes from the Dutch company Hollandse
Signaalapparaten. Its IRSCAN system works in the same way, but is more compact,
lighter in weight and uses more sophisticated sensors arranged in a so-called
focal plane array. This arrangement of sensors is still under development
at Spar for a second generation AN/SAR-8.

In HSA’s focal plane array, the infrared sensors and some preprocessing
circuits lie side by side, in a matrix. Such an integrated array gives more
sensitivity to small hot spots and can distinguish between missiles and
aircraft.

AN/SAR-8’s more conventional system relies on first passing the signals
from the sensors through a series of wires and amplifiers before they reach
the processing circuits. It is a more cumbersome arrangement, but Spar is
nearer than its competitors to producing a finished system.

Garry Brown, Spar’s manager of combat systems, maintains that the two
systems have different functions. ‘HSA’s system is designed to link into
a last ditch weapons system such as a Gatling gun, whereas ours serves missiles
and other defences that need to intercept further out.’ AN/SAR-8 has a greater
range, he says. Its telescopic lens has a larger aperture, so it can collect
weaker signals from a greater volume of air and over a longer distance.

Earle McCurdy, Secretary of the Fishermen, Food and Allied Workers Union,
says that ‘we sounded the alarm much earlier’ than 1988, when the problem
first came to light. But, he adds ‘our concerns were dismissed by the government.’
Officials claimed the phenomenon was temporary, perhaps due to a seasonal
drop in water temperature around the banks. Meanwhile, the government encouraged
more investment in the fishing industry, and too many fishermen ended up
chasing too few fish.

Fish stocks are higher than 20 years ago, but scientists are concerned
about the unexpectedly slow growth in the biomass and a drop in fish size
since 1984. To help conserve stocks, the federal government sharply sliced
northern cod quotas, from 295 000 tonnes in 1988 to 197 000 tonnes, forcing
fishermen to tie up their boats and plants to close.

Not all agree that the northern cod is in danger. Murray Cooligan, vice-president
of the processing company National Sea Products, says ‘our trawlermen say
the fishing has never been better’.

He claims scientists simply cannot find all the fish. For instance,
he says that their survey boats cover a huge area at random and don’t follow
temperature gradients to where cod congregate. Nor are they equipped to
use the latest hydro-acoustic techniques. Jean Jacques Maguire, a senior
scientist with the Canadian Department of Fisheries and Oceans, admits ‘forecasting
the weather is better’.

Nevertheless, the report of a federally appointed task force supports
the fishermen’s contention*. The report published earlier this month says
that mortality rates since 1977 have been ‘at least’ double that predicted
by scientific models.

These claimed fishermen only took 20 per cent of the ‘exploitable’ biomass
– fish old enough kill – while the true figure hovered closer to 45 per
cent.

‘Lots of errors led to faulty conclusions,’ says Lesley Harris, president
of Memorial University in Newfoundland and head of the task force. The models
failed to account for electronic tracking devices improving catching efficiency,
for instance. Wasteful practices such as ‘stripping off’ – landing only
the best fish and throwing the rest overboard – meant that perhaps 20 per
cent of the catch was not counted.

Also cod can live for 15 years, so data for this length of time is needed.
But studies do not go back that far. And with environmental changes and
‘irresponsible and cynical’ pirating by EEC trawlermen, says Harris, ‘our
mathematical models were imprecise, to say the least’.

Fortunately, he explained, ‘fish are an infinitely renewable resource
so we can build them back’. His report recommends not just reducing the
fish kill by half, but total overhaul of fish assessment.

* Independent Review of the State of the Northern Cod Stock, The Communications
Directorate, the Department of Fisheries, Canada.

About two-thirds of the wines produced today employ ‘starters’ – yeasts
added at the beginning of fermentation which help to control quality. Most
growers rely on commercial yeasts prepared to precise specifications. They
buy these yeasts from concerns such as the Canadian company L’Allemand,
in Montreal, which is the biggest supplier in the world.

Now the company has applied to the French authorities for approval to
test genetically engineered yeast in experimental vats in France. As the
technique involves the use of genetically engineered products in the production
of food for human consumption, this case could set a precedent throughout
Europe. Richard de Gre, L’Allemand’s president, does not expect the authorities
to grant approval for the yeast before next September.

Wine growers find that many musts are spoiled by rogue yeasts carried
on the skins of harvested grapes. These ‘killer yeasts’ proliferate during
fermentation and emit toxins which can kill the commercial starters and
spoil the flavour of the wine.

In the past, there was no easy way to prevent such contamination. Sometimes,
the yeasts even added new flavours that turned out to be valuable. So growers
often turned the rogue yeasts into next year’s starters, and today, two-thirds
of commercial wine yeasts include genetic stock from such ‘tame’ killer
types.

The tame varieties still produce toxins, but these do not affect the
wine’s flavour. They even help to control contamination by killing off some
of the rogue yeasts on the harvested grapes. But they do not kill all of
them. Now, L’Allemand wants to transform commercial strains that are still
sensitive to attack by other rogue yeasts into completely resistant types
by genetic manipulation.

L’Allemand started its work on this project with commercial varieties
of common killer strains and isolated the genes that produce the toxin.
The company’s scientists then combined the portions of these genes in sensitive
yeasts to create new commercial varieties. Tests showed that these yeasts
were effective at resisting attack, and panels of wine tasters pronounced
the quality of small quantities of wine made from these yeasts to be unimpaired.

The plant, operated by the West German company BASF, made trichlorophenol.
Rohleder claims the company presented the data in a way that disguised the
cancers. Dioxins, unwanted chemical by-products of many combustion processes,
poison some laboratory animals outright, and can cause cancer in others.
Large doses of dioxins cause chloracne, a serious skin ailment, in humans.
Partly because they have always had to rely on unreliable data, toxicologists
have never established unequivocally whether exposure to dioxins can give
people cancer or other long-term sickness.

The incident which Rohleder reviewed occurred on 17 November 1953 after
a runaway chemical reaction at a plant operated by BASF in Ludwigshafen.
The reaction released dioxins into the factory and its neighbourhood.

An investigation of the mortalilty records of the exposed workers published
in 1985 on behalf of the Born Berufsgenossenschaft (BG) – the industry association
which handles liability claims – became the foundation for refusing compensation
to workers. It dismissed associations between exposure to dioxin and cancer.

The BG report rekindled controversy about dioxin within the German scientific
community, and spurred victims and their families to take their cases to
the courts. Eventually, the government invited Rohleder, an epidemiologist,
to evaluate the evidence independently. The report of his findings provoked
controversy at an international symposium on dioxins in Toronto, Canada,
late last month.

Rohleder compared three sets of data: one, from BASF’s medical department,
formed the basis of the pivotal study in 1985 for the BG; a second, from
the state medical officer of commerce, was based on earlier data collected
by the BG; and a third set recently collected by the BG in response to a
growing clamour to re-examine the evidence. All sets of data originated
from the medical departments of BASF.

The data for the original BASF study mentioned 153 workers classed as
having been exposed to dioxin. The most recent data say that only 122 people
were exposed. Rohleder compared the medical histories of individuals on
both lists, and concluded that BASF included in its list 20 supervisors
who he believes were not exposed.

Another such comparison revealed that the company listed 18 workers
as suffering from dermatitis – a milder skin infection – when the BG reported
clear cases of chloracne, a sign of dioxin poisoning.

The study gauged exposure to dioxin by examining the severity of the
skin disease. But Rohleder says that because many of the skin ailments were
‘misclassified’, the investigators found no clear relationship between exposure
and skin disease. They then argued against any relationship between dioxin
exposure and cancer mortality, although their own research revealed an unexpectedly
high incidence of deaths from cancer in the group with chloracne.

In his own evaluation, Rohleder investigated BASF’s 153 workers but
eliminated the 20 supervisors. He also eliminated the only two women in
the sample, making the final group sufficiently uniform for standard epidemiological
analysis.

Rohleder grouped together neoplasms of the larynx, trachea, bronchi
and lung and other cancers of the respiratory organs. He observed 8 deaths
from cancer, instead of the expected 3.01, giving a statistically significant
standardised mortality ratio of 2.66. By adding cancers of the digestive
tract in a similar fashion he found an identical ratio.

Despite the small size of the sample Rohleder concludes that: ‘This
analysis adds further evidence to an association between dioxin exposure
and human malignancy.’ When contacted by New ÐÓ°ÉÔ­´´ this week, a spokesman
for BASF said the company was unaware of the new analysis presented by Rohleder
in Toronto.