West Coast 0.3m Rural Aerial Photos Index Tiles (2016-2017)
Index Tiles ONLY, for actual orthophotos see layer [West Coast 0.3m Rural Aerial Photos (2016-2017)]( http://data.linz.govt.nz/layer/9 5552)
Orthophotography in the West Coast Region taken in the flying season (summer period) 2016 -17. Coverage is in the Westland District.
Imagery was captured for the ‘West Coast Regional Council’ by Aerial Surveys Ltd, Unit A1, 8 Saturn Place, Albany,0632, New Zealand.
Data comprises:
•1,261 ortho-rectified RGB GeoTIFF images in NZTM projection, tiled into the LINZ Standard 1:5,000 tile layout
•Tile layout in NZTM projection containing relevant information.
The supplied imagery is in terms of New Zealand Transverse Mercator (NZTM) map projection. The products are tiled into NZTopo50 1:5,000 tiles. Please refer to the supplied tile layout shape file for specific details, naming conventions, etc.
Imagery supplied as 30cm pixel resolution (0.3m GSD), 3-band (RGB) uncompressed GeoTIFF. The final spatial accuracy is ±0.6 m @ 68% confidence level in clear open spaces (2 sigma) over area of interest. ±2.0 m or better in the very steep terrain areas of
the Southern Alps.
Simple
Identification info
- Date (Creation)
- 2017
- Status
- Completed
- Point of contact
-
Role Organisation Electronic mail address Point of contact Toitū Te Whenua Land Information New Zealand
- Spatial representation type
- Grid
Spatial resolution
Equivalent scale
- Denominator
- 5000
- Topic category
-
- Imagery base maps earth cover
Extent
))
Resource format
- Title
-
*.xml
- Date
- Edition
-
Unknown
Resource constraints
- Classification
- Unclassified
Resource constraints
- Use limitation
-
Copyright of this work is owned by West Coast Regional Council © West Coast Regional Council
- Use constraints
- Copyright
Resource constraints
- Use limitation
-
Released by LINZ under Creative Commons Attribution 4.0 International (CC BY 4.0) with: Following Attribution: "Sourced from the LINZ Data Service and licensed by West Coast Regional Council for reuse under CC BY 4.0" For details see: https://www.linz.govt.nz/data/licensing-and-using-data/attributing-elevation-or-aerial-imagery-data
- Use constraints
- License
- Language
- English
- Character encoding
- UTF8
Resource lineage
- Statement
-
Data Acquisition:
The aerial photography for this project was captured within the 2016/17 flying season (September
2016 – April 2017) on the following dates:
8th, 16th, 17th, 23rd, 27th February, 8th, 9th March 2017.
All photography was captured using Vexcel's digital UCE camera and flown at:
0.3 m GSD: 18928 ft (5769 m) flying height
Camera Lens: 100 mm
Sun Angle
Minimum of +35 degrees
Data Processing
All aspects of the data processing from imagery processing to DTM creation and ortho production
and product deliverables was undertaken in-house by Aerial Surveys staff & Cyient.
Map Projection
All spatial data for this project provided in terms of New Zealand Transverse Mercator (NZTM) map
projection. The datum is New Zealand Geodetic Datum 2000. The height datum is orthometric
Lyttelton 1937 (sea level).
Image Processing and Aerial Triangulation
All imagery has gone through QA checks ensuring there is no cloud cover and cloud shadow. During
aerial acquisition the aircraft on-board GPS navigation data and ground base station data collected
and post processed. Imagery processed to level 3 and checked for colour correctness/radiometry and
even tonal balance across each project area. The aerial triangulation brings together the GPS data
and imagery using a two part process which stitches the imagery together using tie point matching
for the relative orientation phase and observing ground control points for the absolute orientation
phase. LINZ control, 8th order horizontal and 4th order vertical and other existing control from Aerial
Surveys control data base were used to strengthen the block adjustment or as independent checks on
position during final QA of the ortho imagery. A final report is generated to check RMSE values are
within specification.
DTM Creation
The DTM creation was collected from stereo imagery using photogrammetric techniques, largely
automated pixel matching and auto-correlation process that creates mass points of the terrain
surface. The final DTM took the form of mass points. A Triangulated Irregular Network (TIN) was then
created and used for the ortho rectification process.
DTM Accuracy: ±0.8 m @ 68% confidence level in clear open areas (1 sigma)
RGB and RGBI Ortho Rectification Process
OOrtho rectification is the process of removing (from the image) the effects of camera tip/tilt and
displacement caused by terrain relief. During this process each frame is 'draped' over the terrain
model and the photograph then becomes 'scaled' and 'levelled' in terms of true ground coordinates.
The generation of seamlines between frames follow natural physical features such as ridges, valleys,
roads and rivers. The seamlines are used for the final ortho mosaic that stitches the imagery together
using feather mosaicking techniques. The ortho imagery is then extracted aligned to LINZ 1:5,000
sheet tile layout.
The ortho imagery was processed to RGBI to ensure a consistent dataset is maintained for the RGB
and RGBI ortho tiles including the same seamlines. Minimal colour adjustment was undertaken in the
RGB, generally over water areas and along coastal foreshore for colour matching and to minimise
glare.
- Hierarchy level
- Dataset
- Other
-
dataset
Reference System Information
- Reference system identifier
- 2193
Metadata constraints
- Use limitation
-
Copyright is owned by Toitū Te Whenua Land Information New Zealand © LINZ
- Use constraints
- Copyright
Metadata constraints
- Use limitation
-
Released by LINZ under Creative Commons Attribution 4.0 International (CC BY 4.0) with: Following Attribution: "Sourced from the LINZ Data Service and licensed for reuse under CC BY 4.0" For details see https://www.linz.govt.nz/data/licensing-and-using-data/attributing-linz-data
- Use constraints
- License
Metadata
- Metadata identifier
- f6217265-d254-53d5-cafe-3ebbc5eec0c4
- Language
- English
- Character encoding
- UTF8
- Contact
-
Role Organisation Electronic mail address Point of contact Toitū Te Whenua Land Information New Zealand
Type of resource
- Resource type
- Dataset
- Name
-
dataset
- Date info (Revision)
- 2018-07-03
Metadata standard
- Title
-
ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata
- Edition
-
1.1