{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Terra/Aqua MODIS RGB composites"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"```{hint} \n",
"Execute the notebook on the training platform >>\n",
"```"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"This module shows the structure of `MODIS MOD021K Level 1B Calibrated Radiances` data and what information of the data files can be used in order to load, browse and visualize the data.\n",
"\n",
"According to NASA, \"The MODIS Level 1B data set contains calibrated and geolocated at-aperture radiances for 36 discrete bands located in the 0.4 µm to 14.4 µm region of the electromagentic spectrum. These data are generated from MODIS Level-1A scans of raw radiance, and in the process are converted to geophysical units of W/(m2 µm sr).\"\n",
"\n",
"\n",
"\n",
"\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"```{admonition} Basic facts\n",
"**Spatial resolution**: `1 km at nadir`
\n",
"**Spatial coverage**: `Global`
\n",
"**Revisit time**: `Daily`
\n",
"**Data availability**: `since 2002`\n",
"```"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"```{admonition} How to access the data\n",
"This notebook uses the MODIS MOD21K dataset from the Terra platform. This data can be ordered via the LAADS DAAC and are distributed in `HDF4-EOS` format, which is based on `HDF4`.\n",
"\n",
"For the example below, you can select files for one single date (`8 April 2024`) and under the tab `LOCATION`, you can select an area over the Mediterranean sea. Then, a file list appears and you can select the file with the time stamp at `09:20 UTC`.\n",
"\n",
"**Note:** You need to register for an Earthdata account in order to be able to download data. \n",
"```"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"
<xarray.DataArray 'getitem-17cd15f3f26e033df0144d6540b08604' (y: 2030, x: 1354)> Size: 11MB\n", "dask.array<mul, shape=(2030, 1354), dtype=float32, chunksize=(1540, 1354), chunktype=numpy.ndarray>\n", "Coordinates:\n", " crs object 8B +proj=longlat +ellps=WGS84 +type=crs\n", "Dimensions without coordinates: y, x\n", "Attributes: (12/18)\n", " name: 1\n", " resolution: 1000\n", " calibration: reflectance\n", " coordinates: ('longitude', 'latitude')\n", " wavelength: 0.645 µm (0.62-0.67 µm)\n", " file_type: hdf_eos_data_1000m\n", " ... ...\n", " start_time: 2024-04-08 09:20:00\n", " end_time: 2024-04-08 09:25:00\n", " reader: modis_l1b\n", " area: Shape: (2030, 1354)\\nLons: <xarray.DataArray 'getit...\n", " _satpy_id: DataID(name='1', wavelength=WavelengthRange(min=0.6...\n", " ancillary_variables: []