[alma-config]Pad locations in both coord systems

Adrian Webster asw at roe.ac.uk
Thu Nov 29 04:32:47 EST 2001


Simon et al.,

The system of coordinates I adopted for my design seemed so natural that it
did not occur to me that it would cause some extra difficulty when surveying
the site. Please find below a revised list of coordinates, in both systems.
Each line now gives:-

1) the pad serial number

2) and 3) the coords in my system, offset from the nominal array centre

4) and 5) the coords in the Chilean system, SAm56 UTM.

Best regards

Adrian

John,

Here are the coordinates of the pads in my current design for the ALMA. The
table gives, on each line, the serial number, x  and y coordinates. The
coordinates are in metres E and N of the nominal "centre" at Chajnantor
South, which is the designated
point for the compact part of the array, at (627807.166, 7453228.830) on the
Chilean National Grid, or whatever it is
called. There are 223 pads in all.

The parts of the array are named as follows:-

pads			name

1 - 60		central disk
61 - 80		central ellipse
81 - 164		concentric rings of the inverse-square array, to 5
km diameter
165 - 212		Reuleaux triangle (the other 12 pads in the Reuleaux
are reused parts of the above 3 components)
213 - 219		Southern Chascon hybrids
220- 223		North-Eastern Chascon hybrids

These pads have all been checked against Bryan's map and are fine as far as
that goes. Whether they are accessible 
by any feasible system of roads is another matter, especially on the eastern
side of the site. The positions of most of the pads are not very critical,
and this includes the Reuleaux triangle, the pads of which are the most
likely to lie in difficult terrain. The electromagnetic properties of thin
rings like the Reuleaux are, in my opinion, very robust against quite
substantial relocations.

Not so, however, the Southern Chascon hybrids. The positions of the
individual pads are not critical, but if it should not prove possible to put
6 - 8 pads somewhere along this E-W line from the eastern edge of the
consecutive rings, running close to the southern boundary of Chascon, the
present hybridization scheme will not work very well and I don't know what
will. This feature seems at the moment to be almost essential. The other
hybrids, to the NE of Chascon, are useful in filling a minor  gap that opens
up in the uv-plane at pa 60 degrees when the baselines are of order 10 km,
but are not as essential; probably  the best way to run a road to them is
from the Reuleaux, from somewhere near pads 170 - 173 or perhaps pad 208.

I attach some plans and maps that may help.

Please do not use the data I am sending you for any other purpose than
checking out the site.

Please acknowledge safe receipt of this e-mail.

Cheers

Adrian.

1     0       0       627808   7453229
2     15      0       627823   7453229
3     32      10      627839   7453239
4     18      32      627825   7453261
5     17      15      627825   7453244
6     32      25      627839   7453254
7     3       29      627811   7453257
8     45      31      627853   7453260
9     8       43      627815   7453272
10    -10     35      627797   7453264
11    -7      50      627800   7453279
12    33      40      627841   7453269
13    -21     45      627786   7453274
14    -36     43      627771   7453272
15    6       58      627813   7453287
16    -18     60      627789   7453289
17    28      54      627835   7453283
18    -8      12      627799   7453241
19    -25     21      627782   7453249
20    -37     -2      627770   7453227
21    -22     6       627786   7453235
22    -38     13      627769   7453242
23    -27     -13     627781   7453216
24    -50     22      627757   7453251
25    -41     -16     627766   7453212
26    -26     -28     627781   7453201
27    -40     -33     627767   7453196
28    -52     7       627755   7453236
29    -29     -43     627778   7453186
30    -20     -55     627787   7453174
31    -53     -25     627754   7453204
32    -43     -47     627764   7453182
33    -61     -5      627746   7453224
34    -6      -14     627801   7453215
35    -5      -34     627802   7453195
36    20      -32     627827   7453196
37    5       -23     627813   7453205
38    8       -41     627815   7453188
39    24      -18     627832   7453211
40    6       -56     627813   7453173
41    35      -29     627842   7453200
42    37      -10     627844   7453219
43    48      -20     627855   7453209
44    20      -50     627827   7453179
45    51      -5      627858   7453223
46    57      8       627864   7453237
47    48      -35     627856   7453194
48    62      -15     627870   7453213
49    34      -52     627842   7453177
50    42      52      627850   7453281
51    32      68      627839   7453297
52    8       73      627815   7453301
53    -12     74      627795   7453303
54    -31     67      627776   7453296
55    -50     48      627757   7453277
56    -35     -60     627772   7453169
57    -19     -70     627788   7453159
58    35      -67     627842   7453162
59    16      -67     627823   7453162
60    -6      -76     627801   7453152
61    58      44      627866   7453273
62    56      65      627863   7453294
63    44      82      627851   7453311
64    11      90      627818   7453319
65    -18     91      627789   7453320
66    -3      106     627804   7453335
67    17      111     627824   7453340
68    37      102     627844   7453331
69    58      98      627865   7453327
70    51      118     627858   7453347
71    62      -47     627869   7453182
72    49      -79     627856   7453150
73    16      -85     627823   7453144
74    -20     -88     627787   7453141
75    35      -94     627842   7453134
76    56      -99     627863   7453130
77    17      -106    627824   7453123
78    -4      -106    627803   7453123
79    39      -115    627846   7453114
80    54      -130    627861   7453099
81    106     109     627914   7453338
82    139     53      627946   7453281
83    139     -44     627946   7453184
84    109     -101    627916   7453128
85    72      -210    627879   7453019
86    162     -164    627969   7453065
87    198     -103    628005   7453126
88    190     80      627997   7453309
89    101     163     627908   7453392
90    23      162     627830   7453391
91    -15     141     627792   7453370
92    -81     27      627726   7453256
93    -60     -128    627747   7453101
94    13      -200    627820   7453029
95    50      233     627857   7453462
96    -95     125     627712   7453354
97    -133    28      627674   7453257
98    -90     -228    627717   7453001
99    71      -333    627879   7452896
100   206     -287    628013   7452942
101   279     -190    628086   7453039
102   306     -20     628113   7453209
103   241     152     628048   7453381
104   163     220     627970   7453448
105   -31     290     627776   7453518
106   -201    55      627606   7453284
107   -220    -163    627588   7453066
108   -174    -314    627633   7452915
109   -58     -462    627749   7452767
110   217     -497    628024   7452732
111   427     -244    628234   7452985
112   427     42      628234   7453271
113   287     271     628094   7453500
114   158     327     627965   7453556
115   -201    325     627606   7453553
116   -343    -128    627464   7453101
117   -279    -443    627528   7452786
118   -42     -686    627765   7452543
119   206     -726    628013   7452503
120   511     -562    628318   7452667
121   640     -322    628447   7452907
122   643     -15     628450   7453214
123   527     217     628334   7453446
124   282     384     628089   7453613
125   42      470     627849   7453699
126   -490    105     627317   7453334
127   -530    -300    627277   7452929
128   -363    -712    627444   7452516
129   -125    -950    627682   7452278
130   216     -990    628023   7452239
131   716     -816    628523   7452413
132   962     -347    628769   7452882
133   891     192     628698   7453421
134   311     486     628119   7453715
135   153     700     627960   7453929
136   -633    185     627174   7453413
137   -784    -506    627023   7452723
138   -210    -1395   627597   7451834
139   145     -1649   627952   7451580
140   883     -1387   628690   7451842
141   1319    -887    629127   7452342
142   1375    -252    629182   7452977
143   1169    312     628976   7453540
144   724     629     628531   7453858
145   -220    875     627587   7454104
146   -1054   26      626753   7453255
147   -1197   -498    626610   7452731
148   -808    -1736   626999   7451493
149   81      -2316   627888   7450913
150   946     -2252   628754   7450977
151   2105    -1197   629912   7452032
152   2081    18      629889   7453247
153   1280    820     629087   7454048
154   486     1034    628293   7454263
155   -435    1240    627372   7454469
156   -1713   -347    626095   7452882
157   -1641   -1720   626166   7451508
158   -546    -3205   627261   7450024
159   970     -3887   628777   7449342
160   2121    -3467   629928   7449762
161   2978    -1998   630785   7451231
162   3034    -54     630841   7453175
163   2351    883     630158   7454112
164   843     1518    628650   7454747
165   8704    7383    636511   7460612
166   8124    7120    635931   7460349
167   7518    6962    635325   7460191
168   6911    6568    634718   7459797
169   6226    6200    634033   7459428
170   5699    5989    633506   7459218
171   4908    5516    632715   7458745
172   4275    5148    632082   7458377
173   4249    4385    632056   7457614
174   3563    3202    631370   7456431
175   3065    2734    630872   7455963
176   2852    2150    630659   7455379
177   2509    1440    630316   7454669
178   2614    -4440   630422   7448788
179   3168    -4923   630975   7448305
180   3827    -5029   631634   7448200
181   4644    -5476   632451   7447753
182   5461    -5555   633268   7447674
183   6111    -5893   633918   7447335
184   6990    -6028   634797   7447201
185   8071    -6212   635878   7447017
186   8598    -6291   636405   7446938
187   9653    -6554   637460   7446675
188   10050   -6300   637857   7446929
189   10075   -6300   637882   7446929
190   10136   -6265   637943   7446964
191   10300   -6300   638107   7446929
192   11307   -6260   639114   7446969
193   12183   -6159   639991   7447069
194   12210   -5292   640017   7447937
195   12315   -4503   640122   7448726
196   12737   -3924   640544   7449305
197   12948   -2846   640755   7450383
198   13027   -1742   640834   7451487
199   13212   -1032   641019   7452197
200   13027   -243    640834   7452986
201   13137   543     640945   7453772
202   12579   1861    640386   7455090
203   12684   2518    640491   7455747
204   12236   3149    640043   7456378
205   11920   4122    639727   7457351
206   11287   4411    639094   7457640
207   10259   5121    638066   7458350
208   9622    5684    637429   7458913
209   9609    5706    637416   7458934
210   9549    5741    637356   7458969
211   9497    5901    637304   7459129
212   9574    6200    637381   7459428
213   3780    -1031   631588   7452197
214   4560    -1050   632368   7452179
215   4597    -2071   632404   7451157
216   5958    -2017   633765   7451212
217   6974    -2236   634781   7450993
218   8244    -2181   636051   7451048
219   9006    -1469   636813   7451760
220   8647    3832    636454   7457060
221   9173    3223    636980   7456452
222   9331    2694    637138   7455923
223   9620    2218    637427   7455447

...........................................

Adrian Webster,
Institute for Astronomy,
Department of Physics and Astronomy,
University of Edinburgh,
Royal Observatory,
Blackford Hill,
Edinburgh EH9 3HJ,
Scotland.
asw at roe.ac.uk
tel: 0131-668-8391
fax: 0131-668-8416

...........................................
 



More information about the Alma-config mailing list