R: Class to Store AMSR-2 Satellite Data

amsr-class {oce} | R Documentation

## Class to Store AMSR-2 Satellite Data

### Description

This class stores data from the AMSR-2 satellite.

### Details

The Advanced Microwave Scanning Radiometer (AMSR-2) is in current operation on the Japan Aerospace Exploration Agency (JAXA) GCOM-W1 space craft, launched in May 2012. Data are processed by Remote Sensing Systems. The satellite completes an ascending and descending pass during local daytime and nighttime hours respectively. Each daily file contains 7 daytime and 7 nighttime maps of variables named as follows within the `data` slot of amsr objects: `timeDay`, `SSTDay`, `LFwindDay` (wind at 10m sensed in the 10.7GHz band), `MFwindDay` (wind at 10m sensed at 18.7GHz), `vaporDay`, `cloudDay`, and `rainDay`, along with similarly-named items that end in `Night`. See [1] for additional information on the instrument, how to cite the data source in a paper, etc.

The bands are stored in `raw` form, to save storage. The accessor function `[[,amsr-method` can provide these values in `raw` form or in physical units; `plot,amsr-method`, and `summary,amsr-method` work with physical units.

### Slots

`data`

  As with all `oce` objects, the `data` slot for `amsr` objects is a `list` containing the main data for the object.

`metadata`

  As with all `oce` objects, the `metadata` slot for `amsr` objects is a `list` containing information about the `data` or about the object itself. Examples that are of common interest include `longitude` and `latitude`, which define the grid.

`processingLog`

  As with all `oce` objects, the `processingLog` slot for `amsr` objects is a `list` with entries describing the creation and evolution of the object. The contents are updated by various `oce` functions to keep a record of processing steps. Object summaries and `processingLogShow` both display the log.

### Modifying slot contents

Although the `[[<-` operator may permit modification of the contents of `amsr` objects (see `[[<-,amsr-method`), it is better to use `oceSetData` and `oceSetMetadata`, because that will save an entry in the `processingLog` to describe the change.

### Retrieving slot contents

The full contents of the `data` and `metadata` slots of a `amsr` object named `amsr` may be retrieved in the standard R way. For example, `slot(amsr, "data")` and `slot(amsr, "metadata")` return the `data` and `metadata` slots, respectively. The `[[,amsr-method` operator can also be used to access slots, with `amsr[["data"]]` and `amsr[["metadata"]]`, respectively. Furthermore, `[[,amsr-method` can be used to retrieve named items (and potentially some derived items) within the `metadata` and `data` slots, the former taking precedence over the latter in the lookup. It is also possible to find items more directly, using `oceGetData` and `oceGetMetadata`, but this cannot retrieve derived items.

### Author(s)

Dan Kelley and Chantelle Layton

### References

1. Information on the satellite, how to cite the data, etc. is provided at `http://www.remss.com/missions/amsr/`.

2. A simple interface for viewing and downloading data is at `http://images.remss.com/amsr/amsr2_data_daily.html`.

### See Also

`landsat-class` for handling data from the Landsat-8 satellite.

Other things related to amsr data: `[[,amsr-method`, `[[<-,amsr-method`, `composite,amsr-method`, `download.amsr`, `plot,amsr-method`, `read.amsr`, `subset,amsr-method`, `summary,amsr-method`

[Package oce version 1.1-1 Index]