Marcie S. Compton
Abstract
New types of remotely sensed data are being announced every month, it seems. Integration between these data sets and GIS increases annually as well. This paper is an outgrowth of a project funded by the Alaska Science and Technology Foundation to introduce miners to new data and processing technologies. AeroMap U.S., international photogrammetric, GIS and remote sensing consultants, has created an Internet Map Server website designed to educate miners and the mining industry on the possibilities provided by a wide variety of remotely sensed imagery for all phases of mining projects. Data sets, Spatial Analyst processing, and our Internet Map Server application will be discussed.
Introduction
New types of remotely sensed data are flooding the market place. Older technologies are still available as well. Sifting through the options to determine the appropriate mix of data sources and processing techniques to provide valuable information without excessive cost is a task for which few organizations have the time, money or inclination. The Alaska Science & Technology Foundation (ASTF) saw the need to assist the local mining industry in sorting through the myriad of options. In September of 1998, Aeromap U.S. was awarded a grant by the ASTF to act as project manager for the Remote Sensing for Mining Applications project.
Project Overview
Working together with several other organizations, our goal was to provide information about the types of remote sensing products currently available, as well as to evaluate the usefulness of the products for the various phases in mining operations. As Project Manager, we coordinated the following efforts:
Working with us on this project in various capacities were:
We selected two sites in Alaska as study areas: Fort Knox Mine, north of Fairbanks; and Nome. These areas were selected to limit sample size and project cost. The data sets we finally received were more complete for the Fort Knox Mine. Consequently, we concentrated our efforts primarily on this study area.
Data Acquisition
We received a variety of airborne and satellite imagery for the purposes of the project. These included:
Satellite
RADARSAT
Landsat
IRS-1DAirborne
Aerial Photography
Multispectral Imagery
Star-3i IFSAR ORI and DEM
7200 hz Coplanar Resistivity
9000 hz Coplanar Resistivity
Magnetics
The RADARSAT data we received was taken in fine-beam mode on September 29, 1998. Quite a bit older, the Landsat imagery was acquired prior to the existence of the mine. Received in the fall of 1998, IRS – 1D image was the first available in Alaska.
The aerial photography was acquired on August 30, 1998, while the multispectral imagery dates from the same timeframe. In October 1998, Intermap spent several hours on a cloudy, blustery night aiming their equipment at the snow-covered slopes to the Northeast of Fairbanks. The data were processed to provide us with both an orthorectified image and a DEM. The geophysical data were acquired by DGGS shortly before the project began. DGGS also provided preliminary vector geologic data for the Fort Knox Mine Site. Fairbanks Gold Mining, Inc. provided previously created planimetric data and a DEM. Two USGS DEMs also proved used during the course of the project. Additionally, ground and airborne control survey data were employed.
Data Processing and Uses
The mining industry is a vast enterprise in Alaska. Members range from individual prospectors to large international corporations. The needs of the community are just as varied as the members themselves. To this end, we attempted to provide general information about the types and uses of data for the particular phases of a mining project from exploration, through development and restoration. Considering the new types of data available since our own data acquisition phase, this strategy has proven prudent.
One aspect of this project, was the (re)introduction of remote sensing and GIS to the local mining community. To that end, several examples of the utility of the various data sets were created. Images were processed to indicate geologic alteration from hydrothermal activity, and vegetation classification, among others. Fused Landsat and IRS imagery provided beneficial visual information. Industry members were particularly impressed with the variety of uses for the DEMs, including visualization, route finding and visibility analyses. A second derivative analysis was performed on each of the geophysical data sets.
Spatial Analyst was employed for several analyses throughout the course of the project. Contours and shaded relief images (Figure 4) were generated from the DEMs. Route planning procedures (Figure 5) and visibility analyses (Figure 6 and Figure 7) were performed, as well as the geophysical analyses. While the analyses were simple in nature, they provided the mining community with appropriate illustrations of solutions to some of their concerns.
Website
Educating the local mining industry about remote sensing products and their usefulness was a primary goal of this project. Our website has been one method of maintaining contact with the mining public. It is more readily updated than the CDs we produced and changes require less internal coordination and expense. The delayed release of ArcIMS has prevented the full implementation of our website. However, we are currently serving our vector and raster data using ArcExplorer at http://astfserver/scripts/Esrimap.dll. Several reports and a wide variety of information pertaining to the project is available at the project website.
We were disappointed with the limited functionality of ArcExplorer, however we were able to meet the majority of our goals. The easy to use interface and understandable options meet the needs of our users. Users can easily zoom in and out, view overlays of vector data on raster data. Vector attribute information can be viewed and used to display the data in a number of ways. Of course, the very nature of our data, primarily raster, means that to provide extensive functionality, we will need to wait for more than the arrival of ArcIMS.
We are serving three different AEP files. All of the data sets are contained in one, the second supplies strictly the satellite data and the third only the radar data. These options are much less overwhelming and require less time.
Summary
The Remote Sensing Technology for Mining Applications project funded by the ASTF has been a success. The mining community has received and has access to valuable information about the myriad of choices as to data and processing techniques that was not available one year ago.
Author Information
Marcie S. Compton
Spatial Data Analyst
AeroMap U.S.
2014 Merrill Field Dr.
Anchorage, AK 99501-4116
(O) 907-272-4495 / (F) 907-274-3265
mcompton@aeromap.com
www.aeromap.com
www.astf.aeromap.com