。。Digital product format:
。。The image product format of CBERS-1 is the CBERS Fast Format. In addition, CRESDA also offer image products in the GeoTIFF format which is much simple for use.
。。CBERS Fast Format
。。The standard format for CBERS-1 digital products is CBERS Fast Format.It is based on the general format for digital products.All field definitions strictly follow American Nation Standards Institute(ANSI) and International Organization for Standardization(ISO) standards.A digital product is referred to as a volume set,A volume set may have one or more volumes,depending on image size and output media density.
。。Header File
。。The first file on each volume,a Read-Me-First file,contains header data.It is in American Standard Code for Information Interchange(ASCII), to ANCI and ISO standards.Alphanumetric fields are left justified and numeric fields are right justified.Dates are given in ANSI full year,month,and day-of-month format.All processing options and map projection information for the product are also contained in this file.
。。Image Files
。。All image files contain only one band of image pixels.There are no header records within the image file,nor are there prefix and/or suffix in the individual image records.
。。Trailer File
。。The last volume of the Fast Format image set includes a trailer file after the image files.This file does not to be read to ingest the image files.The trailer file contains ancilliary information that is not relevant to describing the format of the digital product.However,the information contained in the trailer file is processing information like ephemeris points so that the approximate spacecraft position for each pixel in the image can be computed.This file is in ASCII,to ANSI and ISO standards.
。。CBERS Fast Format volume set contains a header file, image files,and a trailer file.The format of the header file is similar the format of the TM header file,so that existing software for reading TM digital products should be able to ingest CBERS digital products with minimal modification.The trailer file provides additional information about the image data.
。。GeoTIFF Format
。。GeoTIFF Format is the improved TIFF 6.0 edition. The map-matched GeoTIFF-format images can be loaded and linked to the accuracte geographic locations in many GIS and image processing software. The GeoTIFF Format is completely compatible with the generic TIFF format.
。。For the GeoTIFF-format CBERS-1 image products, each file name is correspond to a different band of CBERS-1 sensor. The first 512 bytes of a GeoTIFF product file is the file header which includes the desciption to the image file such as product ID and image size (lines and samples per line), etc. In addition, an parameter file named product ID with an extension .ODL is also offered together. This parameter file mainly includes the detailed description to the product, such as orbit number, date of data acquisition, solar elevation angle, the longitudes and latitudes for the four corners and the center of the scene, and satellite systematic parameters and statistical data for use in geometric correction, etc.

。。Annotation format of optical image product:
。。For the optical image product, the image-related parameters are annotated outside the image border, please refer to the following picture.


Level 2 optical image product for the region of TianJin.

。。The explanation to the annotation outside the border:
。。The color numbers in the upper left corner indicate the composite bands. For example, the "Bands 4, 3, 2" in the color composite image means that Band 4 is for Red channel, Band 3 for Green channel, and Band 2 for Blue channel.
。。The numbers in the upper right corner indicate that the path, row and float fraction of the scene. For example, the "WRS373/056-00" means that the image is referred to the World Reference System, the path number is 373, row number is 56, and 00 indicates the scened is processed without float. One scene can be floated by 0% to 99% without change to the image size.
。。Under the image border annotations described are the production sequence number, satellite name, sensor type, longitude and latitude of the scene center, product level, product orientation, scene size (full or quarter), geographic coordinate system, projection name, zone number of the projection, date of data acquisition, solar azimuth and evelvation angles, name of ground receiving station, and the original output aperture of image pixel, etc.
。。Description of annotations for the image frame:
。。The white annotations of the image frame are the map coordinates for the map projection, the unit is meter. The capital characters S and N indicate the map coordinates in south-north direction, E and W indicate the map coordinates in the east-west direction.
。。The red annotations of the image frame are the longtitudes (E, W) and latitude (S, N).