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Hello List
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As mentioned in my post before, sometimes I need to do a resurvey.
<br>As the cave is an underwater cave and therefore the waterlevel can change I need to "correct" the depth readings.
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E.g.:
<br>The initial survey was done and the water depth at the start station was -5m at this time.
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The resurvey was done at a different time and the water level at the same start station was -9m.
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(to use positive numbers inside the data I use: "calibrate depth 0 -1")
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initial survey:
<br>centerline
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data diving from to length compass backcompass fromdepth todepth left right up down
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calibrate depth 0 -1
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10 11 2.04 160 - 5.2 3.9 [ - -] [ - -] [ - -] [ - -]
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...
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endcenterline
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resurvey:
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centerline
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data diving from to length compass backcompass fromdepth todepth left right up down
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calibrate depth 4 -1
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0 1 3.09 284 - 9.2 11.4 [ 0.2 2.6] [ 0.2 0.9] [ - -] [ 2.2 0.2]
<br>1 2 2.92 298 - 11.4 12.5 [ 2.6 1.8] [ 0.9 1.3] [ - 1.1] [ 0.2 1.1]
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2 3 1.96 259 - 12.5 13.7 [ 1.8 1.2] [ 1.3 1.2] [ 1.1 1.2] [ 1.1 0.0]
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...
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endcenterline
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Station 10 from the initial survey is identical to station 0 from resurvey and I do connect these using equate command.
<br>Due to the different waterlevel there is a difference of 4.0m in depth readings.
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To correct this I used "calibrate depth 4 -1" within the resurvey data.
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My assumption for e.g. station 0 was: (9.2 - 4) * -1 = -5.2 (identical to station 10 from initial survey: (5.2 - 0) * -1 = -5.2)
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(as discribed in the therion book on page 19: measured value = (read value - zero error) * scale)
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But doing so I get an error from the compiler:
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therion 6.0.0 (2021-07-13)
<br>- using Proj 5.1.0, compiled against 5.1.0
<br>initialization file: C:\Program Files (x86)\Therion/therion.ini
<br>reading ... done
<br>configuration file: thconfig-survey.thc
<br>reading ... done
<br>reading source files ... done
<br>preprocessing database ... done
<br>C:\Program Files (x86)\Therion\therion.exe: error -- test.th [64] -- length reading is less than change in depth
<br>writing xtherion file ... done
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Line 64 is station 2 from resurvey. Depth difference is 13,7-12,5=1,2 and Distance is 1,96 (1,96 > 1,2).
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I don't understand this error.
<br>When changing "calibrate depth 4 -1" to "calibrate depth 0 -1" in the resurvey
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there is no error compiling the data. But the depth readings are not correct then.
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What do I get wrong with calibrate command?
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Torsten
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