PlanetServer (PS) console allows for quick and easy access to certain functions, either restricted to the console itself (e.g. return or a certain value, parameter), or affecting the various views or widget, such as Map, Diagram. It is available when a certain CRISM observation (data product/granule) is loaded, either interactively from the main WebGUI or directly with a URL.
For example, CRISM IR could be reached through (see spectral range in “Diagram” widget):
while CRISM VNIR of the same granule (see spectral range in “Diagram” widget):
Please note that features and capabilities are evolving. Updates will be posted in this blog and eventual corrections applied to existing documentation/blog posts, including this one. Current information refers to the stable client on http://planetserver.eu (September 2013).
More general information is contained in the PlanetServer 101 post.
Averaging pixels for extracting spectra is possible on PlanetServer, using a certain kernel size, e.g. the default in collecting a spectra is a 3×3 pixel kernel over the point of collection/query. The maximum bin is 7×7. The bin size can be changed using the bin() function in the console:
Using bin 5x5
Using maximum bin of 7×7
The stretch applied to the original floating point values of each band of the hyperspectral CRISM cube can be modified, when rendering in 8-bit (0:255) original data for display on the WebGUI. The default is zero.
setting it to a different value affects all following image display (either single band or e.g. indexes) e.g.
WCPS> minstretch = 0.01
Single band, RGB composites
To load a single bands on the main window through a console command one could directly call for a single band number (as listed in the Table of Contents), e.g. for
The same could be expressed in nanometers, e.g.:
which shows in both cases such a result:
RGB images with a band colour composite can be obtained with, e.g.:
which provides, as a result:
Ratios between different bands can be produced and visualised with, e.g.:
WCPS> image("band200 / band24")
Indexes / summary products
Mineral indexes are implemented in PS and its console, their formula is returned as console output, e.g., after loading a certain CRISM observation and its IR channel:
(data.106 / (0.1*data.12 + 0.1*data.32 + 0.4*data.50 + 0.4*data.71 ) ) - 1
where “sp” stands for “summary product”.
Indexes can also be visualized interactively in the map window, e.g. on this data product (CRISM VNIR):
returns on the console:
for data in ( frt00012613_07_if164l_trr3_1_01 ) return encode( (char) (255 / (max((data.106 / (0.1*data.12 + 0.1*data.32 + 0.4*data.50 + 0.4*data.71 ) ) - 1) - 0)) * (((data.106 / (0.1*data.12 + 0.1*data.32 + 0.4*data.50 + 0.4*data.71 ) ) - 1) - 0), "png" )
and on the main window:
This list summarizes the summary products one could extract and visualize with PS (see Pelkey et al., 2007, DOI:10.1029/2006JE002831 for description and explanations).
Summary products can be listed from the console (also reproduced in the lists below) with:
Hyperspectral Summary Products IR:
Spectral Summary Products VNIR:
Spectral Summary Products IR
CAVEAT: on the stable client/WebGUI the IR and VNIR channels are separate and not all indexes are available (e.g. sp.olindex is not available on VNIR, but only on the IR spectral range), e.g. in VNIR the console returns:
(data.0 / (0.1*data.0 + 0.1*data.0 + 0.4*data.0 + 0.4*data.0 ) ) - 1
Metadata and other parameters
Similarly, available metadata can be listed with:
Minimum, maximum of a certain band can be returned by the console, either expressed as band number or, as in this example, in nanometers:
Alternatively, once could query by band number, such as:
A function for calculating band depth is also available, providing low, center, high in nanometers, e.g, for
WCPS> banddepth(440, 530, 709)
(1 - (data.25 / ((0.6588279348436623 * data.12) + (0.3411720651563377 * data.53))))
one could visualise the image of the desired band depth:
WCPS> bdimage(440, 530, 709)
Console interaction with Menu button functions
The console can returns the point coordinate (p) and spectrum (s) of the points clicked using the Spectrum button
Once a spectrum point is collected, e.g. on
The console returns the ascii spectrum (µm, value) with
The position of the collected spectrum is returned with
This can also be expressed in latitude and longitude, separately:
Similarly, after collecting 2 spectra (first=red, second=green) from the WebGUI (previous section), one could visualise their ratio:
e.g. the 2 collected spectra, in order:
As an alternative to selecting a certain band from the Table of Contents and visualising its histogram from from the “Diagrams” widget, one could interactively visualise the histogram of a certain band, e.g. expressed in nanometers, from the console. The second argument is the number of bins:
WCPS> histogram(nm2band(550), 10)