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Hemispherical Photography
Last modified by Bec Trevithick on 2016/11/09 14:26
Hemispherical photography - digital camera and hemispheric lens, raw imagery and ancillary data, Australian field sites
Contents
Figure 1: Hemispherical image taken at Chowilla, South Australia.
Link to Data
| Descriptor | Data link | Layer name |
|---|---|---|
| Persistent URL | http://www.auscover.org.au/purl/hemispherical-photography-all-sites | |
| GeoNetwork record | Not Available Yet | |
| Data Portal (in development) | http://qld.auscover.org.au/public/html/field/index.html |
Data licence and Access rights
| Item | Detail |
|---|---|
| Rights | Rights owned by JRSRP. Rights licensed subject to Creative Commons Attribution (CC BY 4.0). |
| Licence | Creative Commons Attribution 4.0 License, http://creativecommons.org/licenses/by/4.0 |
| Access | These data can be freely downloaded and used subject to the CC BY licence. Attribution and citation is required as described at http://www.auscover.org.au/citation. We ask that you send us citations and copies of publications arising from work that use these data. |
Abstract or Summary
Hemispherical photography has been used in studies of LAI (Chen et al., 1997; Robison & McCarthy, 1999; van Gardingen et al., 1999; Welles, 1990; Whitford et al., 1995). Hemispherical photography has also been used to measure canopy architecture of boreal forests (Fournier et al. 1997), and the light environment in old growth temperate rain forests (Weiss 2000). Hemispherical photography can provide a number of structural measurements that can be used for calibration and validation of LiDAR derived products. This field data will be suitable for integration with the LiDAR data for calibration and validation of LiDAR derived fractional cover and leaf area index.
Spatial and Temporal extents
| Item | Detail |
|---|---|
| Spatial resolution | 1 ha |
| Spatial coverage (degrees) | 110.000000 to 155.001329 E, -10.000000 to -45.000512 N |
| Temporal resolution | 1 day |
| Temporal coverage | 2012-01-31, ongoing |
| Sensor and instrument | Digital camera and hemispheric lens |
| Item | Detail |
|---|---|
| Spatial representation type | vector - point |
| Spatial reference system | WGS 84 |
Point of contact
| Item | Detail |
|---|---|
| Name | Rebecca Trevithick |
| Organisation | Remote Sensing Centre - Qld Department of Science, Information Technology and Innovation (DSITI) |
| Position | Senior Scientist |
| rebecca.trevithick@qld.gov.au | |
| Role | pointOfContact |
| Address | Remote Sensing Centre, DSITI, EcoSciences Precinct |
| Telephone | (07) 3170 5679 |
Credit
The following organisations contributed to the data collection:
- Joint Remotes Sensing Research Project
- Royal Melbourne Institute of Technology
- Curtin University
- University of Adelaide
- CSIRO
Keywords
| Thesauri | Keyword |
|---|---|
| GCMD | EARTH SCIENCE > BIOSPHERE > VEGETATION > VEGETATION COVER |
| CF | vegetation_area_fraction |
| FoR | Environmental Sciences > Ecological Applications = 0501 |
There are three main thesauri that AusCover recommends:
- Global Change Master Directory (http://gcmd.nasa.gov)
- Climate and Forecast (CF) convention standard names (http://cfconventions.org/standard-names.html).
- Fields of Research codes (http://www.abs.gov.au/ausstats/abs@.nsf/0/6BB427AB9696C225CA2574180004463E?opendocument).
Data quality
Data quality for this data set is assured by adherence to the data collection protocol for hemispherical photography (see References section for full details).
Validation status
Related products
| Item | Product link |
|---|---|
| SLATS star transect | SLATS Star Transect Data |
| Leaf area index (LAI) | Not Available Yet |
| Ground LiDAR | TLS Products |
References
| Item | Detail or link |
|---|---|
| Online info | Field data collection protocol: Hemispherical |
Sampling strategy
A sample of images (5, 7 or 13 depending on site) are collected in a star or cross formation around a central point. All images are referenced to the central geographic location. The naming convention of the imagery enables positioning of each individual image in relation to that central point (see Instrument Data Naming Convention) for details. Three images are collected at each sampling point, one at three different exposures. Samples are collected at dawn, dusk or overcast conditions. See the AusCover hemispherical data collection protocol for full details on collection method (see References).
Product version history
| Version label | Detail |
|---|---|
| 1.0 | Initial release |
Instrument data filenaming convention
Filenames for instrument data conforms to the AusCover naming convention. This convention is an adaptation of the convention developed by the Queensland governments Remote Sensing Centre. The standard form of this convention is:
<sensor category code><instument code><product code>_<longitude>e<latitude>s_<yyyymmdd>_<processing stage code>_<additional dataset specific tags>
The following table describes the meaning of the unique codes used for this product.
| Data Naming Element | Code | Descriptor |
|---|---|---|
| Standard Elements | ||
| sensor category | dc | digital camera |
| instrument | hm | hemispheric lens |
| product | re | reflectance |
| ir | infrared | |
| processing stage | aa0 | raw instrument data |
| data projection | g0 | geographic coordinates |
| Data Specific Elements | ||
| h | h<3 digit code> | height from ground imagery taken at in centimetres |
| a | a<3 digit code> | azimuth of transect running from plot centre to camera location in degrees from North |
| d | d<2 digit code> | distance from plot centre along transect |
Shapefile/KMZ file attribute metadata
| Shapefile Field | Description (units) | Format |
|---|---|---|
| supersite | AusCover calibration/validation site | Text |
| sensor | Code in naming convention – for hemispheric photography always dc, specifying digital camera | Text |
| instrument | Code in naming convention specifying instrument used – for hemispheric imagery always hm, specifying hemispheric lens | Text |
| product | Code specifying type of imagery obtained: re – standard reflectance ir – infrared camera | Text |
| scene | Identifier for plot location given in longitude latitude combination | Text |
| date | Date of data collection given in yyyymmdd format | Text |
| azimuth | Azimuth of transect from plot centre to photo collection point in degrees from north (degrees) | Integer |
| height | Height from ground photo taken (cm) | Integer |
| distance | Distance from centre, along transect running from plot centre to photo collection point (m) | Float |
| obs_key | Unique identifier for site visit | Text |
| id | Database id for data management purposes | Integer |
| exposure | Exposure bracketing. Number represents f-stop under automatic exposure photo taken at, eg. 1 represents an f-stop of -1 | Integer |
| photo | Name of photo according to AusCover naming convention | Text |
| make | Make of camera | Text |
| lens | Details of lens | Text |
| dpi | Maximum dpi raw images obtained at | Integer |
| model | Camera model details | Text |
Metadata history
| Date | Detail |
|---|---|
| 2013-09-13 | Metadata creation date |
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