On the shape of energy-detection ROC curves

A numerical study shows that energy-detection ROC curves based on chi-squared distributions may be accurately represented by binormal receiver operating characteristic (ROC) curves. This allows the detector accuracy and the ROC shape (asymmetry) to be expressed simply in terms of the distribution parameters. An established approximate formula for the shape of energy-detection ROC curves is shown to be inaccurate. An improved approximately is presented.