Most of the memos that I have written are specific to the
Chandra Xray Observatory. On this page you will find links to some that may be of
more general interest. I am placing them here in the hope that the
reader will find them to be of some pedagogical value.
 The Multilayer Reflectivity memo presents
a selfcontained derivation of the reflection and transmission
probabilties of a plane classical electromagnetc wave incident upon a
multilayer with complex indices of refraction.
 The Combining Error Ellipses memo was
written to show how to combine a number of independent estimates of a
source's position to obtain an improved estimate of its position.
Here I have adopted a general multivariate approach and discuss
tangent plane projections.
 Creating the ``Behr Memo'' was my introduction
to Bayesian methods. Here the technique is applied to the ratio of
two Poisson rates (a hardness ratio).
