[g__day (Matthew)]

Sorry to drone on folk,

I just followed the rest of Gary's advice and added the Harmonic terms(DCEC, DCES, HCEC and HCES), which brings RMS down to 20 arc seconds (so +/- 10 arc seconds = wow!) - now you're talking!

This changes the Tpoint alignment SCP advice yet again to:

Southern Hemisphere

************* AZIMUTH ************
MA: +166 seconds (+2.8 minutes).
Rotate axis East (counterclockwise).
For latitude -33.79°, the azimuth adjustment is 3.3 minutes.
Sigma=15.716

************* ALTITUDE ************
ME: +82 seconds (+1.4 minutes).
The polar axis should be lowered +82 seconds (+1.4 minutes).
Sigma=21.243


* fit

coeff change value sigma

1 IH +70.234 +70.23 35.008
2 ID +93.833 +93.83 45.150
3 NP -27.242 -27.24 15.434
4 CH -170.121 -170.12 36.278
5 ME +81.423 +81.42 21.243
6 MA +165.643 +165.64 15.716
7 TF +91.513 +91.51 38.162
8 HCES +40.758 +40.76 18.575
9 HCEC +124.462 +124.46 26.770
10 DCES -142.175 -142.18 31.814
11 DCEC -56.605 -56.61 45.030
12 DAF -118.588 -118.59 22.289

Sky RMS = 20.27
Popn SD = 22.27

* Correlations between terms:

ID -0.2593
NP -0.5549 -0.1389
CH +0.0004 -0.0070 +0.4676
ME +0.5718 -0.5949 -0.1076 +0.0692
MA -0.0024 +0.1444 +0.2958 -0.0012 -0.5019
TF +0.9704 -0.1218 -0.5491 +0.1521 +0.4671 +0.0285
HCES -0.3847 -0.2571 +0.6540 +0.6933 +0.2381 -0.3068 -0.3131
HCEC -0.7244 +0.1203 +0.1882 -0.6552 -0.3797 -0.0065 -0.8145 -0.0815
DCES -0.8065 +0.6383 +0.2446 -0.1047 -0.4589 -0.2263 -0.7542 +0.1637 +0.6304
DCEC -0.4243 -0.6793 +0.5010 -0.0913 -0.0937 +0.2144 -0.5275 +0.2585 +0.4139 -0.1285
DAF +0.5095 -0.1736 +0.1972 +0.8341 +0.3376 +0.1204 +0.6016 +0.3332 -0.9257 -0.5351 -0.2203

IH ID NP CH ME MA TF HCES HCEC DCES DCEC

Action was taken to correct ill-conditioning. The
current FITTOL tolerance is 0.01, which exceeds
values from 7.38e-006 to 0.00994 encountered
during the fit.

* fit

coeff change value sigma

1 IH +0.062 +70.30 35.025
2 ID -0.002 +93.83 45.206
3 NP +0.301 -26.94 15.434
4 CH -0.072 -170.19 36.258
5 ME +0.210 +81.63 21.241
6 MA -0.071 +165.57 15.717
7 TF -0.156 +91.36 38.170
8 HCES -0.062 +40.70 18.571
9 HCEC +0.225 +124.69 26.775
10 DCES +0.272 -141.90 31.837
11 DCEC +0.031 -56.57 45.012
12 DAF -0.019 -118.61 22.258

Sky RMS = 20.27
Popn SD = 22.27

* Correlations between terms:

ID -0.2597
NP -0.5559 -0.1377
CH +0.0003 -0.0066 +0.4667
ME +0.5717 -0.5966 -0.1090 +0.0680
MA -0.0031 +0.1453 +0.2968 -0.0013 -0.5020
TF +0.9706 -0.1233 -0.5500 +0.1517 +0.4669 +0.0282
HCES -0.3843 -0.2544 +0.6529 +0.6946 +0.2373 -0.3071 -0.3122
HCEC -0.7244 +0.1205 +0.1895 -0.6552 -0.3788 -0.0059 -0.8144 -0.0829
DCES -0.8069 +0.6385 +0.2458 -0.1047 -0.4603 -0.2247 -0.7554 +0.1645 +0.6308
DCEC -0.4238 -0.6796 +0.5013 -0.0911 -0.0912 +0.2137 -0.5260 +0.2561 +0.4134 -0.1284
DAF +0.5100 -0.1737 +0.1955 +0.8337 +0.3372 +0.1198 +0.6020 +0.3340 -0.9259 -0.5357 -0.2200

IH ID NP CH ME MA TF HCES HCEC DCES DCEC

Action was taken to correct ill-conditioning. The
current FITTOL tolerance is 0.01, which exceeds
values from 0.000102 to 0.00996 encountered
during the fit.

IH : = +70.30
ID : = +93.83
NP : = -26.94
CH : = -170.19
ME : = +81.63
MA : = +165.57
TF : = +91.36
HCES : = +40.70
HCEC : = +124.69
DCES : = -141.90
DCEC : = -56.57
DAF : = -118.61