| 24 | |
| 25 | 11th Mar. 2008: Note that the email below were the numbers as originally received, but calculation of the Gamma angle contains an error - "gam = acos( abs(dz) / dst )" should use asin, not acos. Del and Dst are unaffected. Investigation of this suggests this causes an along-track error of approx. 1.5m in all 2006/2007 delivered data for ATM, which may be partially corrected by boresight correction (since these numbers were computed using the incorrect lever-arm numbers) depending on flight altitude. Other sensors have smaller errors, since the effect of the original calculation error is smaller for the offset angles of these sensors. Correct lever-arm numbers are below for reference, new boresight numbers would need to be computed to use these. |
| 26 | |
| 27 | Corrected 2006/7 lever-arm numbers |
| 28 | || || Gam || Del || Dst || |
| 29 | || ATM || 1.306 || 0.006353 || 1.741 || |
| 30 | || Casi || 1.098 || 0.007934 || 1.702 || |
| 31 | || Eagle || 0.873 || 0.000781 || 1.994 || |
| 32 | || Hawk || 0.806 || 0.000682 || 2.117 || |