| 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 |