Survey name | Type | Altitude | Spacing | Flight line distance |
---|---|---|---|---|
Dubuque | M/R-D | 121.9 m | 9.60 km | 2,634 km |
Northeast Iowa | M-A | 304.8 m above ground | 1.60 km | 12,713 km |
East-central Iowa | M-A | 304.8 m above ground | 1.60 km | 12,070 km |
Northwest Illinois | M-D | 548.6 m (barometer) | 4.80 km | 2,341 km |
SW Wisconsin-NW Illinois | M-D | 609.6 m (barometer) | 0.80 km | 7,563 km |
Southwest Wisconsin | M-D | 304.8 m above ground | 0.80 km | 22,128 km |
Wisconsin Tie Lines | M-D | 304.8 m above ground | 0.80 km | 2,293 km |