Measurements of the Fabry-Pérot efficiency and resolving power were made during ground testing using a far-infrared laser at a number of spot wavelengths (Emery et al. 1993, [15]). It has proved difficult to confirm these measurements in-orbit owing to an absence of emission lines that are sufficiently narrow so that the intrinsic width of the line can be ignored with respect to the resolution element of the Fabry-Pérot. The presence of transient effects (Section 6.9) also causes the lines to be artificially broadened. The resolving power as derived from ground testing are listed in Table 5.22.
| FP | Det. |  |
res. power | res. element |
[ m] |
[m] |
|||
| FPS | SW1 | 47.00 | 8600 | 0.0055 |
| SW2 | 56.17 | 8450 | 0.0066 | |
| SW3 | 66.09 | 8200 | 0.0081 | |
| FPL | SW4 | 75.68 | 7800 | 0.0097 |
| SW5 | 84.80 | 9200 | 0.0092 | |
| LW1 | 102.42 | 9700 | 0.0105 | |
| LW2 | 122.19 | 9600 | 0.0127 | |
| LW3 | 141.78 | 9250 | 0.0153 | |
| LW4 | 160.59 | 8900 | 0.0180 | |
| LW5 | 178.00 | 8500 | 0.0209 |