ASTER Alteration Package

aster_alteration_junacipio_sericite

PhotoSat offers a geological alteration mapping package produced using archive ASTER satellite photos. In areas of sparse vegetation, ASTER data is used to map clay, iron oxide, and silica minerals for epithermal gold and silver and porphyry copper exploration. The best ASTER satellite scenes are selected from a worldwide archive to provide alteration and geological information for your project area.

Alteration Package includes:

  • Silica alteration
  • Hydroxyl alteration: Intensity¹
  • Hydroxyl alteration: Kaolinite² – alunite³
  • Sericite alteration
  • Iron Oxide alteration
  • Colour image
  • Vegetation intensity
  • Greyscale image

¹ Minerals with OH such as: alunite, sericite, kaolinite, dickite, illite, and montmorillonite
² Kaolinite or other minerals with an absorption peak at 2.16 microns
³ Alunite or other minerals with an absorption peak at 2.2 microns

Advanced products:

Spectral matching: Spectral matching uses the spectral signature of a pixel to look for other similar pixels. If there is an outcrop of significant interest, we can analyze the spectral signature of a pixel related to that outcrop and provide a map of other pixels in the ASTER scenes that are similar. We can work with only the exact location of the outcrop.  It is best if you can provide photographs and a detailed geologic description of the outcrop.

Lithological enhancement: Lithological enhancement is a statistical analysis of the spectral signature that reveals the strongest spectral differences over the visible, near infrared and shortwave infrared bands. Outcrops and soil will show differences in lithology, while vegetated areas will just show the differences in vegetation.  The process works best when there is a significant amount of soil and/or rock exposure.

ASTER alteration package pricing

The alteration mapping data is provided on a project-by-project basis. Please provide us with the extents of your project area and we will prepare a quote.

For more information contact us at info@photosat.ca or 1-604-681-9770.

SILICA ALTERATION with greyscale image

AsterMapping_big07

HYDROXYL ALTERATION: INTENSITY with greyscale image

AsterMapping_big04

HYDROXYL ALTERATION: KAOLINITE – ALUNITE with greyscale image

AsterMapping_big05

SERICITE ALTERATION with greyscale image

AsterMapping_big06

IRON OXIDE ALTERATION with greyscale image

AsterMapping_big03

Advanced Processing:
SPECTRAL MATCHING – match to the spectral signature of specified locations

AsterMapping_big09

Advanced Processing:
Lithological Enhancement

AsterMapping_big10

COLOUR bands 2, 3, 1

AsterMapping_big01

COLOUR bands 9, 3, 1

AsterMapping_big02

VEGETATION

AsterMapping_big08

Deliverables

  • Eight orthorectified alteration images:
    • Silica alteration
    • Hydroxyl alteration: Intensity
    • Hydroxyl alteration: Kaolinite – alunite
    • Sericite alteration
    • Iron Oxide alteration
    • Colour image
    • Vegetation intensity
    • Greyscale image
  • 14 orthorectified multispectral bands

Technical Specifications

Scene Dimensions: ~60 km x 60 km
Map Projection: UTM, Others on request
Datum: WGS84, NAD27, NAD83 – Others on request
Format: Alteration and Colour Images: GEOTIFF
Multispectral Data: BIL with ER Mapper and ArcInfo header files
Pixel Size: VNIR=12.5m, SWIR=25m, TIR=75m
Media: CD / DVD / FTP

 

Image Resolution Pixel Size
Iron Oxide Alteration Zones
Colour Image
Greyscale Image
Vegetation Intensity
15m 12.5m
Hydroxyl Alteration Zones
Hydroxyl Alteration Zones: Probable Kaolinite – Probable Alunite
Sericite Alteration Zones
30m 25m
Silica Zones 90m 75m

 

License Agreement

  • PhotoSat General Terms of Sale