| ADD-SPECTRA | Sum spectra in X and Y, result in X; Y lost |
| AVERAGE-SPECTRA | Average with right weights for integration time, Tsys |
| DIVIDE-SPECTRUM | Divide X-register spectrum by constant |
| FORM-QUOTIENT-SPECTRA | Divide Y-register spectrum by X-register spectrum |
| MULTIPLY-SPECTRA | Multiply X-register spectrum by a constant factor |
| OFFSET-SPECTRUM | Add a d.c. offset to the X-register spectrum |
| SUBTRACT-SPECTRUM | Subtract X from Y, result in X; Y lost. |
The commands MULTIPLY-SPECTRUM and DIVIDE-SPECTRUM operate on the current spectrum with a scalar. OFFSET-SPECTRUM adds a scalar quantity to all data elements in the spectrum.
ADD-SPECTRA adds the current spectrum to the one above it in the stack, while SUBTRACT-SPECTRUM subtracts it from the one above it. AVERAGE-SPECTRUM averages the two spectra with weights defined by their integration times and system noise temperatures. FORM-QUOTIENT-SPECTRUM can be used to divide all points in the Y-array by the corresponding points in the X-array.