DP ME 6, Version 2, 2006. Airborne Magnetometer Survey Images, Total Field and Vertical Gradient Images Covering 11D, 11E, 11F, 11G, 11J, 11K, 11N, 20O, 20P, 21A, 21B and 21H, (200 m X 200 m Resolution)
DP ME 6, Version 2, 2006. Airborne Magnetometer Survey Images, Total Field and Vertical Gradient Images Covering 11D, 11E, 11F, 11G, 11J, 11K, 11N, 20O, 20P, 21A, 21B and 21H, (200 m X 200 m Resolution).
Originator:
Nova Scotia Department of Natural Resources, Mineral Resources Branch
Publication Date:
August 2006
Edition:
Version 2
Data Type:
remote-sensing image
Series:
Digital Product
Issue Identification:
DP ME 6
Publisher:
Nova Scotia Department of Natural Resources, Mineral Resources Branch
This data set consists of 24 color TIFF images with a resolution of 200 m X 200 m covering 12 1:250 000 NTS mapsheets, where airborne magnetometer surveys exist over Nova Scotia. Twelve of the TIFF images represent the total field aeromagnetics for the entire province, while the other twelve represent the vertical gradient aeromagnetics. Each of the 24 images also comes with an ESRI world file (.tfw) that is used by the Arc suite of products to georeference the image. The original data were collected by aeromagnetic surveys flown by the Geological Survey of Canada (GSC).
Purpose:
The TIFFs are to be used as a backdrop behind other geological layers to assist with geological interpretations.
Supplemental Information:
Data Set ID = m006nsam;
Data Class = magnetic;
Project ID = RFP1994;
old dataset ID = aeromag;
old data class = images
Language
English
Data Credit:
Nova Scotia Department of Natural Resources
Data Environment
ArcInfo 8.2 on a SUN Sparc 20 workstation running Solaris 7
The access constraints are contained in the following License Agreement which the user must agree to before using the data. A copy of the License Agreement is included with the digital product. The License Agreement reads as follows:
"For the data contained on this medium (media), or any part thereof, herein called the DATA
Between the PROVINCE OF NOVA SCOTIA as represented by the Nova Scotia Department of Natural Resources, hereinafter referred to as NR&R and the recipient of the data hereinafter called the USER
For good consideration, the receipt of which is acknowledged, NR&R licences the non-exclusive use of the digital DATA to the USER on the following terms and conditions.
TERMS AND CONDITIONS
NR&R remains the owner of the DATA and is not assigning copyright privileges to the USER.
The USER agrees to acknowledge NR&R as the source of the DATA, if using or distributing it in its original form, whether in whole or in part, or as part of a value added product.
NR&R reserves the right to modify and/or update the DATA without obligations to notify the USER.
The DATA is provided to the USER on an "as is" basis, without warranties of any kind, express or implied.
The entire risk as to the quality and accuracy of the DATA is with the USER and the USER shall use his/her own judgment in making use of the DATA or drawing conclusions based upon it.
NR&R shall not be liable to the USER, his/her clients, servants, agents, contractors, assigns, or to any other person for any loss or damage of any kind including personal injury or death arising from the use of the DATA or accompanying written materials, or from errors, deficiencies or faults therein, whether such damage is caused by negligence or otherwise. If errors or omissions are found in the DATA, the USER will notify NR&R.
This Licence is the entire Agreement between the parties and supersedes all previous Agreements or understandings between NR&R and the USER hereto, whether written or oral, in connection with or incidental to the DATA. This Licence shall be binding upon the parties hereto and each of their executors, administrators, successors and assigns and shall ensure to the benefit of such executors, administrators, successors and authorized assigns.
This Licence must be included with the DATA if the USER copies, resells, or re-distributes the DATA whether in whole or in part.
This Licence can be terminated by NR&R at any time. Upon such termination, the USER shall refrain from using the DATA and destroy all copies and backups in the USER'S possession.
This Licence is in effect once the USER reads and accepts the Terms and Conditions of this Licence. If the USER is unable or unwilling to fully comply with these terms and conditions, the USER must refrain from using the DATA. By using the DATA, the USER acknowledges that he/she was aware of the terms and conditions of this Licence when he/she accepted it, understood them, and agreed to be bound by them."
A copy of the terms and conditions of the license are available with the downloaded product.
Use Constraints:
Any constraints on the use of the data are contained in the above license agreement. The terms and conditions of the license accompany the downloaded digital product. A statement of some use constraints can be viewed in the technical prerequisites.
There may be positional accuracy errors in the data that came from the original data collection. The survey data was acquired from the Geophysical Data Centre, GSC, Ottawa in 16 bit signed integer raster grid format. The data were then linearly compressed to 8 bit file formats and geo-referenced to the NSGC 1:500 000 planimetric base map for Nova Scotia. Subsequently these data were contrast enhanced using a non-linear technique to facilitate visual appearance and interpretation. Quantitative image analysis using these data is possible, however accurate quantitative data analysis requires the original 16 bit values, which are available from the Geophysical Data Center, Ottawa.
"non-linear technique to facilitate visual appearance and interpretation" means to permanently alter data values within a grid so that a narrow range of grid cell values represent the data over a wider range of values. In this case 'non-linear' refers to the mathematical model used in controlling the input and output data value ranges. Once this operation is performed on a grid it is irreversible and returning to the original data values is impossible unless the exact input parameters and mathematical modelling equation is known. The entire risk as to the quality and accuracy of the data is with the user and the user shall use his/her own judgment in making use of the data or drawing conclusions from it.
Total field airborne magnetometer data have been systematically acquired for the province of Nova Scotia. A combination of GSC in-house surveys and external contract surveys and external surveys through various Federal/Provincial Programs have resulted in complete coverage of the province. In total 15 surveys have been flown ranging in date from the 1950's to 1990. The data from these surveys vary with respect to instrumentation, flight parameters (altitude, line spacing, digital/analogue recording, noise levels) and processing. Tables 1 and 2 provide information on digitally acquired data for the period 1970 to 1990. Tables 1 and 2 are provided as an html page at,A,Prior to 1970, all acquisition was analogue-based; contour maps were later digitized along flight path lines to generate digital profile data.
A regional aeromagnetic dataset covering the entire province has been created by the GSC by merging the individual surveys. The data have been levelled to a common datum, ensuring a match along coincident boundaries and referenced to the Definitive Geomagnetic Reference Field (DGRF). They are available from the GSC, as either grid or profile data.
Two tables are provided with the metadata in a file called gsc_surveys.wpd
Table 1. Description of data coverage from GSC in-house aeromagnetic surveys
Table 2. Description of data coverage from Federal/Provincial contract survey programs.
As part of the NSNR&R RFP 1994-001148 Synmap Information Technologies acquired the survey data from the Geophysical Data Centre, GSC, Ottawa in 16 bit signed integer raster grid format. The data was then linearly compressed to 8 bit file formats and georeferenced to the NSGC 1:500 000 planimetric base map for Nova Scotia. Subsequently these data were contrast enhanced using a non-linear technique to facilitate visual appearance and interpretation. Quantitative image analysis using these data is possible, however accurate quantitative data analysis requires the original 16 bit values, which are available from the Geophysical Data Center. The data products have been converted from the original format to a TIFF raster file format that is compatible with ESRI's ArcInfo GIS.
Footnotes: "non-linear technique to facilitate visual appearance and interpretation" means to permanently alter data values within a grid so that a narrow range of grid cell values represent the data over a wider range of values. In this case 'non-linear' refers to the mathematical model used in controlling the input and output data value ranges. Once this operation is performed on a grid it is irreversible and returning to the original data values is impossible unless the exact input parameters and mathematical modelling equation are known.
In January 2006 the data set was renamed from AEROMAG to M006NSAM and moved from the IMAGE directory on the MRB "S" drive to the MAGNETIC directory. This work was done by Brian Fisher.
The images were renamed in January 2006. The NSTFxxx.TIF image series were renamed to TF_200_xxx.TIF and the NSVGxxx.TIF series was renamed to VG_200_xxx.TIF, where xxx stands for the 1:250 000 NTS sheet name. The images were also re-projected from UTM zone 20 NAD27 to UTM zone 20 NAD83 using an AML for re-projecting single band images. This work was done by Angie Ehler.
The DATA is provided to the USER on an "as is" basis, without warranties of any kind, express or implied.
The entire risk as to the quality and accuracy of the DATA is with the USER and the USER shall use his/her own judgment in making use of the DATA or drawing conclusions based upon it.
NR&R shall not be liable to the USER, his/her clients, servants, agents, contractors, assigns, or to any other person for any loss or damage of any kind including personal injury or death arising from the use of the DATA or accompanying written materials, or from errors, deficiencies or faults therein, whether such damage is caused by negligence or otherwise. If errors or omissions are found in the DATA, the USER will notify NR&R.
The terms and conditions of the license accompany the downloaded digital product.
Technical Prerequisite:
In order to view our digital files on your computer, you require mapping software (e. g. ArcView(R), MapInfo(R), AutoCAD(R)). If you do not have this software, ESRI* provides a FREE Map Viewer called ArcExplorer(R) which you can download over the Internet. ArcExplorer(R) works with our "E00" and "TIFF" files. You need to download both ArcExplorer(R) and the ArcExplorer(R) Import Utility (Import71.exe). The import utility is required to convert the ArcInfo "E00" files into ArcInfo coverages, which then can be viewed in ArcExplorer(R).
Ordering Fee:
Free
Instructions:
The data set can be downloaded over the Internet.
Distribution Contact:
see contact information
Digital Form: (1 of 2)
format name:
TIFF
format specification:
dp006v2_tf_tf.exe
Transfer Size:
2.6 MB
Dataset Size:
4.1 MB
Information Content:
TIFF images for Nova Scotia divided into several images based on the NTS 1:250 000 map sheets. The image for each map sheet is further divided into TIFF images for total field aeromagnetics. Also included is an ESRI world file (.tfw) used to georeference the image.
TIFF images for Nova Scotia divided into several images based on the NTS 1:250 000 map sheets. The image for each map sheet is further divided into TIFF images for vertical gradient aeromagnetics. Also included is an ESRI world file (.tfw) used to georeference the image.