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ocssw
V2022
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Go to the source code of this file.
vegetation_indices.c - Utility functions for vegetation index calculations | |
Functions useful to the implementation of vegetation index algorithms
| |
| #define | NUM_BANDS_TO_BE_HYPERSPECTRAL 50 |
| const int32_t | blu_min = 459 |
| const int32_t | blu_max = 479 |
| const int32_t | red_min = 620 |
| const int32_t | red_max = 670 |
| const int32_t | nir_min = 841 |
| const int32_t | nir_max = 876 |
| const int32_t | grn_min = 480 |
| const int32_t | grn_max = 537 |
| const int32_t | modis_b4_min = 545 |
| const int32_t | modis_b4_max = 565 |
| const int32_t | modis_b11_min = 526 |
| const int32_t | modis_b11_max = 536 |
| float | average_rhos_values (float rhos_values[], size_t length) |
| bool | invalid_pixel (double pixel_elevation, double pixel_mask, double rhos_values[], int len_rhos_values) |
| float | clamp (float pixel_value, int minimum, int maximum) |
| bool | instrument_is_hyperspectral (int32_t num_bands) |
Macro Definition Documentation
◆ NUM_BANDS_TO_BE_HYPERSPECTRAL
| #define NUM_BANDS_TO_BE_HYPERSPECTRAL 50 |
Definition at line 11 of file vegetation_indices.c.
Function Documentation
◆ average_rhos_values()
| float average_rhos_values | ( | float | rhos_values[], |
| size_t | length | ||
| ) |
Get the average of rho_s values from a hyperspectral measurement to approximate a multi-band measurement.
- Parameters
-
uint16_t rho_s_values An array of rho_s values to average size_t length An integer indicating the size of wavelengths
- Returns
- the average value of the values in rho_s_values
Definition at line 27 of file vegetation_indices.c.
◆ clamp()
| float clamp | ( | float | pixel_value, |
| int | minimum, | ||
| int | maximum | ||
| ) |
Clamp the value of a pixel between minval and maxval.
- Parameters
-
pixel_value A float representing a the vegetation index minimum Lower bound to which pixel_value will be clamped maximum Upper bound to which pixel_value will be clamped
- Returns
- pixel_value clamped between minimum and maximum
Definition at line 49 of file vegetation_indices.c.
◆ instrument_is_hyperspectral()
| bool instrument_is_hyperspectral | ( | int32_t | num_bands | ) |
Definition at line 53 of file vegetation_indices.c.
◆ invalid_pixel()
| bool invalid_pixel | ( | double | pixel_elevation, |
| double | pixel_mask, | ||
| double | rhos_values[], | ||
| int | len_rhos_values | ||
| ) |
Check pixel attributes for validity.
- Parameters
-
pixel_elevation Measured pixel elevation ASL pixel_mask Bitwise AND b/n this pixel's flags and a mask rhos_values Array of doubles representing measured surface reflectances in a number of bands len_rhos_values Number of bands for which a rho_s value has been measured
- Returns
- true if there is something wrong with any of the given attributes, false otherwise
Definition at line 35 of file vegetation_indices.c.
Variable Documentation
◆ blu_max
| const int32_t blu_max = 479 |
Definition at line 15 of file vegetation_indices.c.
◆ blu_min
| const int32_t blu_min = 459 |
Definition at line 14 of file vegetation_indices.c.
◆ grn_max
| const int32_t grn_max = 537 |
Definition at line 21 of file vegetation_indices.c.
◆ grn_min
| const int32_t grn_min = 480 |
Definition at line 20 of file vegetation_indices.c.
◆ modis_b11_max
| const int32_t modis_b11_max = 536 |
Definition at line 25 of file vegetation_indices.c.
◆ modis_b11_min
| const int32_t modis_b11_min = 526 |
Definition at line 24 of file vegetation_indices.c.
◆ modis_b4_max
| const int32_t modis_b4_max = 565 |
Definition at line 23 of file vegetation_indices.c.
◆ modis_b4_min
| const int32_t modis_b4_min = 545 |
Definition at line 22 of file vegetation_indices.c.
◆ nir_max
| const int32_t nir_max = 876 |
Definition at line 19 of file vegetation_indices.c.
◆ nir_min
| const int32_t nir_min = 841 |
Definition at line 18 of file vegetation_indices.c.
◆ red_max
| const int32_t red_max = 670 |
Definition at line 17 of file vegetation_indices.c.
◆ red_min
| const int32_t red_min = 620 |
Definition at line 16 of file vegetation_indices.c.
