On the cover of The New Standard Aspectarian are the words "Accurate", "Reliable", and "Convenient".  Let's take those factors one at a time and see what they mean.


ACCURATE

An aspectarian can be no better than the data that is utilized in its computations.  The quality of data can be expressed in terms of accuracy and precision.  Since we are differentiating between those two terms, it seems useful to indicate how they are being used here.

Precision relates to how sharply a numerical description specifies the quantity – for instance, the number of significant digits.

Accuracy relates to how closely a numerical description approximates the truth.

For example, let us say that we are going to measure an object that has been established by a highly trustworthy source as being exactly 10 cm long.  We make two independent measurements of the object, using different methods.  The first method yields a result of 10.0396 cm, and the second method yields a result of 10.02 cm.  The first method is more precise than the second, but the second method is more accurate than the first.  Ideally it is desirable to achieve both high accuracy and high precision.

The ephemeris data which is utilized by The New Standard Aspectarian is furnished by the U.S. Naval Observatory and is the most accurate and most precise data of its kind available on planet Earth.

One of the primary factors in computing aspect peak times and positions accurately is the method used for interpolating between the daily positions furnished by the ephemeris.  The simplest and easiest method is known as linear interpolation.  In linear interpolation, the planets are assumed to move absolutely uniformly, and only two sets of daily positions are used: those for the beginning of the day of interest (the day for which aspects are being computed) and those for the end of the day of interest.  However, the planets do not move absolutely uniformly, and so linear interpolation yields results which are inaccurate.  In order to improve the accuracy, it is necessary to employ nonlinear interpolation, which makes use of at least three sets of daily positions – with the day of interest located somewhere within the interval, as close to the middle as possible for maximum accuracy.  The accuracy can be further improved by increasing the number of sets of daily positions used, such as by using four sets.

The New Standard Aspectarian makes use of five sets of daily positions to compute one day's worth of aspects, and the day of interest straddles the middle of the range.  This provides a very high degree of useful nonlinear interpolation, ensuring maximum accuracy in the computation of aspect peak times and positions.

The computational methods employed in creating The New Standard Aspectarian utilize 12-digit precision, which far exceeds the precision of the data that is used.  Truncation is not performed until the computation for each aspect reaches the phase for translation into peak time and position.

In the motions of the planets, some very special situations can sometimes arise.  Specifically, if a planet becomes stationary (in either longitude or declination) on the day for which aspects are being computed, that planet could very well form two separate aspects with another planet or could cross a sign cusp (or the equator) twice on that day – once before it becomes stationary and once after it becomes stationary.  Furthermore, it is possible for two planets to become stationary on the same day and to aspect each other twice on that day.  Some aspectarian programs might not even detect the presence of these special aspects, but the method used in computing The New Standard Aspectarian not only detects them unfailingly but also computes their peak times with high accuracy.

Why all this emphasis on accuracy and precision?  Why all this care in the computation of aspects?  The answer is: to produce an aspectarian that is truly Accurate, Reliable, and Convenient – to set a new standard of trustworthiness in the realm of aspectarians.


RELIABLE

The ephemeris data which is obtained from the U.S. Naval Observatory is in the form of a recorded disk (CD-ROM).  Data files derived from that disk are manipulated electronically from beginning to end as files, not as individual data, and are utilized directly by the computer in that form.  Therefore there is no need for human intervention at the level of individual data, thereby eliminating any avenue for human error.

Furthermore, the results of the computations - the complete printed listings: numbers, special symbols, and text – are printed out directly and automatically, generated by the computer itself, again with no human intervention in the data-transfer process.  This greatly maximizes the overall accuracy and integrity of the final product.

The computing techniques and procedures associated with The New Standard Aspectarian have been thoroughly tested over a period of years and have been found to be totally trustworthy.


CONVENIENT

Everything about the embodiment of The New Standard Aspectarian is rigged for maximum convenience.  It contains the aspects for a period of one month, and each day's aspects are printed on a page of their own: one day, one page.

Each page contains four columns of information.  The column on the left shows the peak times of the aspects.  The second column shows the aspects themselves.  (The nonlunar aspects are emphasized for quick and easy reference by being offset slightly to the left so that they may be easily seen with a rapid scan.)  The pair of columns on the right show the positions.

For further quick-scan convenience, extra space is used to separate the aspects which peak before noon from those which peak after noon.

If you are in the Pacific Time Zone, you have the added convenience of being able to read the aspect peak times directly, without the need for time conversions.  For a brief list of conversions for some other time zones, please refer to the Format chapter.