roo wrote: ↑Sun Jul 30, 2017 2:51 am
points to line up are in the spreadsheet Column N

column N contains the following entries

2 to 1

5 to 3

34 to 17

5 to 3

then,

roo wrote: ↑Sun Jul 30, 2017 2:51 am
* Start with 2 SS to 1 TS as known points to align Station 1

* Station 1 common points 5 T1 to 3 T2

* Station 2 common points 5 T1 to 3 T2 to match Station 1

* Station 3 common points 34 D to 17 G to match Station 2 and Station 1 respectively.

None of these instructions match data in column N. So i look nearby and see column M

in column M, there is an entry called '2 SS'

there is no entry called '1 TS'

(do you mean '1 PM'?)

there are two entries called '5 T1' how do i know which entry belong to which station? i assumed the colors green/orange/yellow would be the stations, but that is not really clear.

there are 2 entries called '34 D' again not clear what is what.

there are 2 entries called '17 G' again not clear what is what.

symbols 3 and 5 repeat and seems to be related to '3 T2' and '5 t1', symbol 17 seems related to both instances of '17 G'.

none of these things are obvious, until you devote some time and energy to sorting it out.

i see a strong connection between the green points and the yellow points through symbol 3 '3 T2' and symbol 5 '5 T1' if these are common points, i can align the green data set to the yellow data set. i dont know how i really feel about symbol 17 and 34. i guess 17 relates orange to green and 34 relates orange to yellow. i would almost bet this is correct if you hadn't mentioned something about 2 SS to 1 TS

could you verify the color coding for the stations, and then drop column M and N

*completely*. Just use column L 'symbol' to identify the connecting points.

if spreadsheet cell '6L', containing symbol '3' is the connecting point for station 1, just use that symbol when you repeat the measurement from another station. i think that's what you did, but the additional instructions don't clarify.

if the above is correct, then a good way to communicate that would be:

"i have two big sets of data points"

"the two big data sets share 1 point in common. it has symbol 17"

"to fix the orientation between the two sets, i have a third set. this third set only has 3 points: 3 and 5 from the first set, and 34 from the second set"

i see a real bearing column all the way at the end. does that mean each station is rotated? if so can i trust the 'real bearing'? how do i align the stations to true north? i would like to end up with the y axis pointing north, and if we have a common bearing, we can fix the orientation before doing a translation on all the data.

even without a common bearing it can be done, we would need to draw triangles [3,5,17] then [3,5,34], then [3,17,34]. by looking at these three triangles, we could see which sides have equal lengths, then we can figure out how to rotate them so the equal side are parallel. then we can translate them.