Satellite identification

Filename matching

Sanchez matches satellite imagery to known satellites based on optional file prefix, optional file suffix, and, when stitching satellite images, by filename timestamp. For images which have the same file structure across different satellites, an optional image root path file can be specified.

File prefixes are registered in Resources\Satellites.json. If you have changed the default file prefix, you will need to edit the appropriate satellite definition.

When stitching images, Sanchez needs to identify the closest satellite imagery based on the provided timestamp. This matching is performed by regular expressions in code. Currently, default filenames created by goesproc, xrit-rx and Electro are supported.

Filename timestamps

Timestamps in all geostationary filenames are UTC, with the exception of Elektro-L No.2 images which are in Russian Standard Time. When creating a stitched image using Electro, Sanchez will choose images based on the converted UTC time, not the local time in the filename itself.

Custom satellite support

Sanchez normalises geostationary satellite imagery to be consistent with images received via GOES-R satellites. It is therefore technically possible for Sanchez to process images from any satellite, provided a suitable section is added to the Resources\Satellites.json file.

Satellite disambiguation

For source images which map to multiple satellites - currently, Elektro-L No.2 and Elektro-L No.3 - an optional JSON file can be specified which contains a map of satellite name and root directory. See File disambiguation for details.

Cropping

Because the Himawari-8, GK-2A and Electro images have a border around the disc that the GOES-16 and GOES-17 images lack, a Crop section is present. This specifies the ratio of pixels to be cropped for top, right, bottom and left edges respectively.

For example, a crop value of 0.007273 for an image of 2200px will result in a crop of 16px. Typically, all four crop values will be the same, but they may be different if a horizontal or vertical offset is required.

Images should be cropped so the image is tight at the equator.

Filename prefix / suffix

The FilenamePrefix and/or FilenameSuffix properties may be populated to disambiguate satellites. Both accept regular expressions.

IR inversion

If the source IR image is inverted, set the Invert property to true.

Filename formats

Sanchez supports the following filename formats. The leading and trailing capturing groups are used to match filename prefixes and suffixes, and the middle capturing group matches the date.

Format	Expected timestamp format	Example
(.*)([0-9]{6}_[0-9]{4})_(.*)\\..*	yyMMdd_HHmm	200830_0330_9.jpg (no prefix)
(.*)_([0-9]{8}_[0-9]{6})(.*)\\..*	yyyyMMdd_HHmmss	IMG_FD_001_IR105_20200912_001006.jpg
(.*)([0-9]{8}T[0-9]{6}Z)(.*)\\..*	yyyyMMddTHHmmssZ	GOES17_FD_CH13_20200830T033031Z.jpg