630315Eclipse3_p1

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ROYAL ASTRONOMICAL SOCIETY OF CANADA
Standing Cozwiittee on Observational Activities
Programme for Solar Eclipse of July 20, 1963,

Bulletin No. 3	   Basic Observation Prograzmne	March 15, 1963
Section A. Precision Observations

    In this bulletin we cover briefly the procedure to be followed for each of the
projects that come under the heading of Precision Observations, as outlined in Bulletin
No.2.


OBSERVER'S CO-ORDINATES

    All reports must give the observer's co-ordinates - latitude, longitude and elevation
above sea level for there is little value in making precision observations unless the
observer knows exactly where he is when he. makes then. For those who have neither the
instruments nor the experience to make an actual survey, the best method is to plot one's
position on a government survey map from which the co-ordinates can then be calculated
with a fair degree of accuracy. If survey maps are not obtainable, the observert s pos-
ition can be plotted on a road map, with a notation giving the distance, as measured by
car speedometer, from the nearest intersection. This road map is then attached to the
observation report. The method of determining co-ordinates or position should always
be stated in the report.


METHODS OF TIMING	

    There are several methods of timing and the one selected will depend on the degree
of accuracy required, the equipment available and personnel available. Four methods
are described below. (Anyone using more elaborate methods needs no guidance from us!)
The timing method used should be stated on the observation report.

(1) With Ordinary Watch. If an ordinary watch or clock with a second hand is used,
    two persons are required - one to watch the phenomenon and one to watch the watch.
    When the observer calls "Time!" the timekeeper notes the time, to the split second
    if possible. This involves some sacrifice on the part of the timekeeper, for he
    cannot take his eyes off the watch. The timekeeper has a record sheet handy and
    several minutes before the phenomenon is scheduled to occur he begins to write
    down the time each minute, making a pencil stroke as each second elapses. He then
    has a means of re-checking his timings later.

        The watch used should be set by radio time signals and its accuracy checked
    for some period both before and after the event. If short-wave time signals are
    not available, then the Dominion Observatory one o'clock time signal on the broad-
    cast band can be used, in which ease the watch must be checked for several days,
    both before and after, and the error noted. The timings should not be adjusted
    for watch error but the record of watch errors should accompany the report.

(2) With Short-Wave Radio. Two persons. are required for this method - one to observe
    the phenomenon and one to record the tine. The timekeeper follows much the same
    procedure as under (1) above, except that he listens instead of watches, writing
    down the time each minute and recording each second that elapses. This method is
    somewhat more accurate than Method (1) but requires great concentration on the
    part of the timekeeper, who will be completely lost if he allows his attention to
    be distracted even momentarily. Also, it is, dependent on good reception throughout.