transforming based on implicit cross-references

I am a rank beginner using xslt 1.0 (Solaris 9 xsltproc) and I am being
provided xml data as in this example:

-------------------------8<--------------------

<timestamp>20091216
	<people>
		<person>	Peter	</person>
		<person>	Robert	</person>
		<person>	Anna	</person>
		<locations>
			<location>	New York	</location>
			<location>	Zurich		</location>
			<location>	Hong Kong 	</location>
		</locations>
	</people>
</timestamp>
<timestamp>20091217
	<people>
		<person>	Anna	</person>
		<person>	Peter	</person>
		<person>	Jason	</person>
		<person>	Robert	</person>
		<locations>
			<location>	Tokyo 	</location>
			<location>	Trenton	</location>
			<location>	Zurich	</location>
			<location>	Mumbai	</location>
		</locations>
	<people>
</timestamp>

-------------------------8<--------------------

Notice that:

- within each <timestamp> the count of "people/person" nodes == the
count of people/locations/location" nodes.  In the first <timestamp>,
there are
three people/person nodes, and there are three corresponding
people/locations/location nodes.  In the second <timestamp> there are
four.
.

- The document order of timestamp/people/person corresponds to the
document order of timestamp/people/locations/location.  For example,
on 20091216 Anna was in Hong Kong; and on 20091217 Anna was in Tokyo.

- The document order of <person> can change:  in the First <timestamp>,
document order is:

	Peter, then Robert, then Anna;

in second <timestamp>, the document order is:

	 Anna, then Peter, then Jason, then Robert.

The names will always be distinct (there is always just one Anna, just
one Robert, etc).

My transformation needs to output just the locations for one person of
interest, for example, if I'm interested in Robert:


<timestamp>20091216
		<person>	Robert	</person>
		<location>	Zurich	</location>
</timestamp>
<timestamp>20091217
		<person>	Robert	</person>
		<location>	Mumbai	</location>
</timestamp>

Is this possible to perform this transformation in my environment?

Thank you in advance,

ed