Table 160 (continued) 461 

 HORIZONTAL VISIBILITY 



Table 160-B1. — Extinction coefficient as a function of visual range of black objects viewed 



against horizon sky in daytime where threshold of luminance contrast, c, is 0.02 



3.912 



Tinge 0.00 °- 01 002 °- 03 °- 04 ° 05 006 °- 07 °- 08 °- 09 



km. km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 



0.40 9.780 9.541 9.314 9.098 8.891 8.693 8.504 8.323 8.150 7.984 



0.50 7.824 7.671 7.523 7.381 7.244 7.113 6.986 6.863 6.745 6.631 



0.60 6.520 6.413 6.310 6.210 6.112 6.018 5.927 5.839 5.753 5.670 



0.70 5.589 5.510 5.433 5.359 5.286 5.216 5.147 5.081 5.015 4.952 



0.80 4.890 4.830 4.771 4.713 4.657 4.602 4.549 4.497 4.445 4.396 



0.90 4.347 4.299 4.252 4.206 4.162 4.118 4.075 4.033 3.992 3.952 



1.00 3.912 3.873 3.835 3.798 3.762 3.726 3.691 3.656 3.622 3.589 



1.10 3.556 3.524 3.493 3.462 3.432 3.402 3.372 3.344 3.315 3.287 



1.20 3.260 3.233 3.207 3.180 3.155 3.130 3.105 3.080 3.056 3.033 



1.30 3.009 2.986 2.964 2.941 2.919 2.898 2.876 2.855 2.835 2.814 



1.40 2.794 2.774 2.755 2.736 2.717 2.698 2.679 2.661 2.643 2.626 



1.50 2.608 2.591 2.574 2.557 2.540 2.524 2.508 2.492 2.476 2.460 



1.60 2.445 2.430 2.415 2.400 2.385 2.371 2.357 2.343 2.329 2.315 



1.70 2.301 2.288 2.274 2.261 2.248 2.235 2.223 2.210 2.198 2.185 



1.80 2.173 2.161 2.149 2.138 2.126 2.115 2.103 2.092 2.081 2.070 



1.90 2.059 2.048 2.037 2.027 2.016 2.006 1.996 1.986 1.976 1.966 



2.00 1.956 1.946 1.937 1.927 1.918 1.908 1.899 1.890 1.881 1.872 



2.10 1.863 1.854 1.845 1.837 1.828 1.820 1.811 1.803 1.794 1.786 



2.20 1.778 1.770 1.762 1.754 1.746 1.739 1.731 1.723 1.716 1.708 



2.30 1.701 1.694 1.686 1.679 1.672 1.665 1.658 1.651 1.644 1.637 



2.40 1.630 1.623 1.617 1.610 1.603 1.597 1.590 1.584 1.577 1.571 



2.50 1.565 1.559 1.552 1.546 1.540 1.534 1.528 1.522 1.516 1.510 



2.60 1.505 1.499 1.493 1.487 1.482 1.476 1.471 1.465 1.460 1.454 



2.70 1.449 1.444 1.438 1.433 1.428 1.423 1.417 1.412 1.407 1.402 



2.80 1.397 1.392 1.387 1.382 1.377 1.373 1.368 1.363 1.358 1.354 



2.90 1.349 1.344 1.340 1.335 1.331 1.326 1.322 1.317 1.313 1.308 



y^e 1 .0 .1 .2 .3 .4 .5 .6 .7 .8 .9 

 v 2 



km. km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 km.- 1 



3.0 1.304 1.262 1.222 1.185 1.151 1.118 1.087 1.057 1.029 1.003 



4.0 0.9780 0.9541 0.9314 0.9098 0.8891 0.8693 0.8504 0.8323 0.8150 0.7984 



5.0 0.7824 0.7671 0.7523 0.7381 0.7244 0.7113 0.6986 0.6863 0.6745 0.6631 



6.0 0.6520 0.6413 0.6310 0.6210 0.6112 0.6018 0.5927 0.5839 0.5753 0.5670 



7.0 0.5589 0.5510 0.5433 0.5359 0.5286 0.5216 0.5147 0.5081 0.5015 0.4952 



8.0 0.4890 0.4830 0.4771 0.4713 0.4657 0.4602 0.4549 0.4497 0.4445 0.4396 



9.0 0.4347 0.4299 0.4252 0.4206 0.4162 0.4118 0.4075 0.4033 0.3992 0.3952 



10.0 0.3912 0.3873 0.3835 0.3798 0.3762 0.3726 0.3691 0.3656 0.3622 0.3589 



(continued) 



SMITHSONIAN METEOROLOGICAL TABLES 



