Mileage: North block: (not available) Central block: 3,514 line miles South block: 2,340 line miles Survey Size: 11,218 miles Flight Lines: NNE-SSW, ¼-mile spacing Tie Lines: WNW-ESE, 5-mile spacing Elevation: 500 feet above ground level Instrumentation: Optically pumped, Cesium-vapor magnetometer, ¼-second sampling Date Flown: February, 1986 Data Provided: Total Magnetic Intensity (IRGF removed) contour map
Survey Size: 35,843 miles Flight Lines: East-West, ½-mile spacing, except, 2-mile spacing in western part of Webb, northeastern part of Duval, and northern part of Jim Wells Counties Tie Lines: a) North-South, 1½-mile spacing in western portion including all or portions of Webb, Zapata, Starr, Jim Hogg, and Duvall Counties b) North-South, 5-mile spacing in
Survey Size: 1,800 line miles (2,897 line km) Flight Lines: East-West, 1-mile (1.6 km) spacing Tie Lines: North-South, 1-mile (1.6 km) spacing Elevation: 500 ft. (152 m) above mean terrain Instrumentation: Geometrics G-813 magnetometer Date Flown: 1993 Data Provided: Total Magnetic Intensity (IRGF removed) contour map Flight Path Map Reduced-To-Pole of TMI map Vertical Derivative
Sampling rate: 0.25 seconds Survey Size: 7,350 miles Flight Lines: N70-W, 1-mile spacing Tie Lines: N20-E, 4-mile spacing Elevation: 500 feet above mean terrain Instrumentation: High-sensitivity, optically pumped magnetometer Data Provided: Total Magnetic Intensity (IRGF removed) contour map Flight Path Map Reduced-To-Pole of TMI map Vertical Derivative map (optional) Horizontal Gradient (optional) Profiles, on paper
Processing: Pearson, deRidder and Johnson, Inc. of Lakewood, Colorado Survey Size: 11,490 miles Flight Lines: East-West, ½-mile spacing Tie Lines: North-South, ½-mile spacing Elevation: 300 feet above mean terrain Instrumentation: High-sensitivity, optically pumped Cesium Vapor magnetometer with 0.25-second sampling Date Flown: 1987 Data Provided: Total Magnetic Intensity (IRGF removed) contour map Flight Path Map Reduced-To-Pole
