UCVM VS30 etree map (Wills 2015) UCVM's interpolation
From SCECpedia
vs30 etree map
In UCVM, the extraction of vs30, surface value from vs30 etree map(ucvm.e) base on Wills 2015 is in src/ucvm/ucvm_map.c
UCVM's method:
From Latlngs, points are converted from geo to xy offset and then calculate the grid point into the etree map 4 corners of interpolation grid plane points are extracted from etree Interpolate_bilinear are called to arrive at the final surf and final vs30 values
Rob's method:
Figure out the closes vs30 etree grid points and then use it
There are 2 big discrepancies in vs30 returned from UCVM and vs30 from Rob
lon lat ucvm Rob -117.95682 33.84007 293.500 294 -117.81793 33.85332 351.900 352 -117.88693 33.88911 312.445 294 <--- A -117.95898 33.86630 228.200 228 -117.93108 33.90853 386.600 387 -117.95576 33.93152 386.600 387 -117.80333 33.92733 385.100 385 -117.85709 33.85299 228.200 228 -118.04687 33.88925 228.200 228 -118.05753 33.92822 386.600 387 -117.86562 34.02098 419.818 352 <--- B -117.98124 33.80772 228.200 228 -117.92242 33.87170 293.500 294 -117.92371 33.94536 385.411 385 -117.95081 34.00950 293.500 294
Adding debug statements to UCVM to output the surf and vs30 from multiple grid points that were used
A: ucvm_query -m cvms5 -l 33.88911,-117.88693,0
>>> grid location: x0 5648 y0 1702 >>> corners -> 0 0 >>> corners -> 1 0 >>> corners -> 0 1 >>> corners -> 1 1 >>> 4 sets of grid point values.. >>>...surf 84.540581 78.770798 79.989998 81.523117 >>>...vs30 386.600006 293.500000 385.100006 293.500000 >>>...FINAL surf 80.292620 vs30 312.445426 -117.8869 33.8891 0.000 80.293 312.445 cvms5 1621.082 854.413 2032.805 none 0.000 0.000 0.000 crust 1621.082 854.413 2032.805
B:ucvm_query -m cvms5 -l 34.02098,-117.86562,0
>>> grid location: x0 5598 y0 1746 >>> corners -> 0 0 >>> corners -> 1 0 >>> corners -> 0 1 >>> corners -> 1 1 >>> 4 sets of grid point values.. >>>...surf 207.701019 182.753067 176.160889 172.366409 >>>...vs30 468.399994 385.100006 468.399994 351.899994 >>>...FINAL surf 179.832657 vs30 419.817623 -117.8656 34.0210 0.000 179.833 419.818 cvms5 1714.918 943.196 2076.987 none 0.000 0.000 0.000 crust 1714.918 943.196 2076.987
For a matching location,
ucvm_query -m cvms5 -l 33.84007,-117.95682,0
>>> grid location: x0 5652 y0 1664 >>> corners -> 0 0 >>> corners -> 1 0 >>> corners -> 0 1 >>> corners -> 1 1 >>> 4 sets of grid point values.. >>>...surf 34.806599 34.438507 37.543068 34.159943 >>>...vs30 293.500000 293.500000 293.500000 293.500000 >>>...FINAL surf 34.435791 vs30 293.500000 -117.9568 33.8401 0.000 34.436 293.500 cvms5 1626.430 833.127 2021.462 none 0.000 0.000 0.000 crust 1626.430 833.127 2021.462
