Integrating Remote Sensing and Surface Geophysics

Problem/Opportunity

The increasing demand for effective environmental assessment and monitoring and the inventory and audit of cultural resources on military lands requires not only the information that can be obtained by commonly used surveying techniques, but also the integration of qualitative, remotely sensed data. The advances in remote sensing and surveying instrumentation are providing opportunities for better and more cost-effective long-term monitoring capabilities, thus reducing the time spent on ground-truthing and field data collection.

Approach

The remotely sensed data sets, which are most commonly used in environmental studies, include raster- and vector-data types that may be used in any Geographic Information System (GIS) software packages. The raster-data type to be identified, assessed, and collected include visible/infrared satellite data (Landsat TM and SPOT images), radar imagery (AVHRR and RADARSAT), airborne sensor data (SIR), and digital terrain models. For example, Landsat images, such as the multispectral scanner (MSS), and TM data consist of electromagnetic radiation (EMR) in 4 or 7 bands. Bands 1 and 2 are useful in detecting cultural features and bands 3, 4, and 5 are used to discriminate water and vegetation, as well as soil and geologic boundaries. Band 6 is useful in detecting heat intensity, insecticide applications, and thermal pollution location. Band 7 is very important for the discrimination of geologic rock type and soil boundaries, as well as moisture content in soil and vegetation. However, a successful integration of remotely sensed data with conventional data requires identification, assessment, and collection of the data that have to be included into a GIs-based database.

Results

At this phase of Argonne's research, gravity and geomagnetic data have been evaluated. The gravity data cover the continental U.S. (including land and sea gravity) and were used to compute gravimetrically derived geodetic deflections by the National Geodetic Survey (NGS) in order to enhance data quality and produce the Gravity Anomaly Map of North America (DNAG). The gravity data can be used to determine bedrock type (Figure 1) and clays in bedrock (Figure 2). Additional data from other sources have been added to the initial database through NOAA's NGDC to a total of 1,677,370 data point values. High-quality geodetic quantities may be computed from this data source.

The geomagnetic data set covers most of North America. The data originated from ship-track, flight line, gridded data, and compiled regional maps. It is uniformly gridded at a 2-km spacing based on a spherical North Transverse Mercator projection and consists of over 2 million grid values that can easily be extracted at a desired point.

Future Plans

Argonne plans to continue to investigate available remotely sensed data to identify information that can contribute to optimizing surface-based geophysics and intrusive investigations.

Figure 1. ANAD Bonguer Gravity Anomaly Map	Figure 2. ANAD Gravity, 2nd Vertical Derivative Map