Each time the amplitude change detection analytic is executed, a set of files are produced. The screen shot below shows the file download options from the Console order page. The files are described in the table below.
|
File Content |
File Type |
Naming Structure |
Description |
|
ACD Changemap |
GeoTIFF |
<file_name>.tiff |
The ACD Change Map is the primary Change Detection product for use.
This is a processed and filtered change map raster with outputs that range [-1 to 1] and correspond the direction and algorithmic significance of the output. Values from –1 to 0 correspond to decreases in amplitude. Values from 0 to 1 correspond to increases in amplitude. These values can be filtered, colorized, and otherwise post-processed by the user. The file name corresponds to the two source images used to produce the ACD Change Map.
The file name corresponds to the window of time used to generate the output as such: CAPELLA_SP_ACD_HH_<start_time_first_image>_<end_time_ second_image>
Example ACD Change Map file naming: CAPELLA_SP_ACD_HH_20221110132541_2022111132455.tiff
Which corresponds to the two Spotlight GEO products from which it was derived, with the first image taking the first date spot: CAPELLA_C07_SP_GEO_HH_20221110132530_20221110132551.tiff CAPELLA_C08_SP_GEO_HH_20221111132445_20221111132506.tiff
|
|
Preview Image |
GeoTIFF |
<file_name>_diag.geojson* |
The Preview Image is an 8-bit file in TIFF format that is used in the Console display. This file includes change detections that are colorized according to the “Red is Fled, Blue is New” pneumonic. The advantage of this file is that it is simple to load into a GIS for a quick view of changes detected. |
|
STAC File |
Json |
<file_name>.json |
A json file containing the metadata for the ACD Change Map. The metadata includes information on the source images that were used in the Change Map. A detailed description of this file and its contents is in the article entitled Change Detection Metadata.
Example file name: CAPELLA_SP_ACD_HH_20221110132541_20221111132455.json |
The source images used to generate the change maps are captured in the JSON metadata using the following key: