DESIGN: PRECISION

What is Precision?
Precision is the degree to which data conforms. Precise data will be able to go out to many decimal places or be able to give us deeper insights into things. Something important, however, is the difference between precision and accuracy. Accurate data is data this is "correct"; Data that conforms to formulae and helps verify them. But if we were taking mainly accurate data, we would learn nothing new. It would just tell us things we already know. Precise data, on the other hand, may not measure things quite right, but it will do it in a very detailed way. This means that if the precisely taken data is even slightly accurate, it can be adjusted to fit models better and thus we'll learn new things!

This is important! Without accuracy, data is hard to interpret, but without precision, the data doesn't teach you anything!

How Much Error Can There be in the SDC?
The detector must be able to detect dust grains as small as 0.8 microns, with mass as low as 4x10^-12 g.

What Causes Error in Precision?
Badly designed instruments can cause precision errors. This means that the data will be spread out and not tell us very much. This can be caused by many things. A poorly designed instrument will introduce systematic error that keeps measurements from being precise. Saturation of the detector can cause it to not respond fully, thus giving us bad information. A high-energy particle hitting the instrument could cause a random error in measurements causing data to be imprecise. There are a number of ways for this error to occur, but there are many safeguards build into spacecraft to help try and minimize this kind of thing as much as possible.

How Can Precision be Improved?
The easiest way to imporve precision is by building a better instrument. Bigger, more components, more detail; All these increase precision. As time passes and technology improves, this naturally occurs, so increasing precision is usually just a matter of time. However, precision can also be increased by taking more measurements. The more measurements taken, the better the idea about the environment. So there are a number of ways to increase precision, but the best still remains time and the forward march of technology.