RACURS has signed a distribution agreement with Capella Space.

Date: 19 may 2021

Type of publication: news

Since 2016, the American company Capella Space has been developing radar solutions, spacecraft and information service, provides on-demand very high-resolution (VHR) Synthetic Aperture Radar (SAR) Earth observation imagery. Through a constellation of small satellites, Capella plans providing easy access to frequent, timely and flexible information about the earth's surface required by specialists in dozens of industries worldwide.

Under the partner agreement, RACURS will distribute Capella’s data in Russia, Belorussia, Moldova, and Armenia.

By April 2021, the Capella constellation consists of three radar (SAR) microsatellites: Capella-2 (Sequoia), Capella 3 and Capella-4. Each satellite will carry an X-band, single-frequency radar capable of acquiring spotlight, sliding spotlight, and stripmap images. The main characteristics of the Capella SAR system are described in Table 1.

Table 1. Capella SAR system characteristics

Capella's SAR satellites support a wide range of look angles and can collect data in different imaging modes. Imaging mode parameters and products specifications for SLC and GEO are in Table 2 and 3, respectively.

Table 2. Specification of the standard single look complex (SLC) image product type

Table 3. Specification of the standard geocoded terrain corrected (GEO) image product type

RACURS develops a software complex PHOTOMOD Radar for spaceborne SAR data processing. The software supports Capella Space images of SLC (Single Look Complex) and GEO (Geocoded Terrain Corrected) processing levels.

The process of importing Capella data from .JSON format into the internal PHOTOMOD Radar .rdp format:

Fig.1 Dialog box for selecting the format and fragment of the image

  
Fig.2. Information box and Capella images metadata

The geocoding process is designed to transform the image from the time-slant range radar coordinate system into the geographic coordinate system on the latitude-longitude grid of the WGS-84 ellipsoid.

Fig 3. Displaying the geocoding processor

Fig 5. Displaying a fragment of a geocoded Capella image on a Google Earth background

As an example, we used a radar image from the Capella-2 (Sequoia) satellite from 01/29/2021 on the territory of Dallas County, Texas, USA. Processing level - SLC (single look complex), mode - Sliding Spotlight (resolution 0.5m in range, 1m in azimuth), polarization - HH.

You can request test data on the official website of Capella Space.

RACURS’s specialists evaluated the quality of Capella samples. The radiometric quality, resolution and metadata geocoding accuracy are shown on the screenshots below. 

Fig 5. Radar image of Lakeview, California, USA

SAR on the Capella-2 (Sequoia) by Capella Space

SpotLight imaging mode, SpotGEO data format

Resolution 0.3 m in range, 0.6 m in azimuth

Visualization in PHOTOMOD Radar software

Fig 7. Radar image of Brawley, Imperial Country, California, USA. SAR on the Capella-2 (Sequoia) by Capella Space. Stripmap mode, SpotSLC data format. Resolution 0.8 m in range, 1.2 m in azimuth. Geocoded in PHOTOMOD Radar software, RACURS Group