Tasseled Cap
Guide by Aaron Zuspan
Overview
The eemont package extends the ee.Image and ee.ImageCollection classes with the method tasseledCap():
ee.Image
|
Calculates tasseled cap brightness, wetness, and greenness components. |
ee.ImageCollection
|
Calculates tasseled cap brightness, wetness, and greenness components for all images in the collection. |
Supported Platforms
Tasseled cap transformation coefficients are published for a number of sensors and processing levels:
Usage
Tasseled cap transformation calculates brightness, greenness, and wetness components from spectral bands. These data transformations can be helpful for both visualization and dimensionality reduction.
To calculate tasseled cap components, we’ll load a supported image (Sentinel-2) and run the tasseledCap method.
img = ee.Image("COPERNICUS/S2/20160111T112432_20160111T113311_T28PDT")
img = img.tasseledCap()
Now if we check the image band names, we’ll see tasseled cap brightness (TCB), greenness (TCG), and wetness (TCW) component bands have been added to our image.
>>> img.bandNames().getInfo()
['B1', 'B2', 'B3' ... 'TCB', 'TCG', 'TCW']
Warning
tasseledCap requires a specific set of bands depending on the dataset. If your image does not contain the correct bands,
you will receive an error like Image.select: Pattern 'B1' did not match any bands. To avoid that, it is safest to run tasseledCap
before subsetting your image bands.
For convenience, we could also run the tasseledCap method on an ee.ImageCollection, which would add TCB, TCG, and TCW bands
to each image.
col = ee.ImageCollection("COPERNICUS/S2")
col = col.tasseledCap()
References
- 1
Shi, T., & Xu, H. (2019). Derivation of Tasseled Cap Transformation Coefficients for Sentinel-2 MSI At-Sensor Reflectance Data. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 1–11. doi:10.1109/jstars.2019.2938388
- 2
Baig, M.H.A., Zhang, L., Shuai, T. and Tong, Q., 2014. Derivation of a tasselled cap transformation based on Landsat 8 at-satellite reflectance. Remote Sensing Letters, 5(5), pp.423-431.
- 3
Huang, C., Wylie, B., Yang, L., Homer, C. and Zylstra, G., 2002. Derivation of a tasselled cap transformation based on Landsat 7 at-satellite reflectance. International journal of remote sensing, 23(8), pp.1741-1748.
- 4
Crist, E.P., Laurin, R. and Cicone, R.C., 1986, September. Vegetation and soils information contained in transformed Thematic Mapper data. In Proceedings of IGARSS’86 symposium (pp. 1465-1470). Paris: European Space Agency Publications Division.
- 5
Crist, E.P. and Cicone, R.C., 1984. A physically-based transformation of Thematic Mapper data—The TM Tasseled Cap. IEEE Transactions on Geoscience and Remote sensing, (3), pp.256-263.
- 6
Crist, E.P., 1985. A TM tasseled cap equivalent transformation for reflectance factor data. Remote sensing of Environment, 17(3), pp.301-306.
- 7
Lobser, S.E. and Cohen, W.B., 2007. MODIS tasselled cap: land cover characteristics expressed through transformed MODIS data. International Journal of Remote Sensing, 28(22), pp.5079-5101.