Photo Credit: Thales, GoogleEarth
Bright Spark is the project name (or codename) for an experimental airborne Synthetic Aperture Radar (SAR). The project started life as a radar pod for the UK’s military drone programme called Watchkeeper which was modified by Thales,UK for Dstl (The British Government’s Defence Science and Technology Laboratory). The idea was to push the art of the possible and achieve resolutions beyond conventional SAR systems in order to explore the effects that resolution has on image interpretability and automated feature extraction.
How ‘Fine’ is Fine Resolution ?
Radars achieve finer resolutions by spreading the transmitted pulses over a range of frequencies (called the bandwidth). The wider the bandwidth, then the finer the resolution. For comparison Cosmo-Skymed and TerraSAR-X can transmit around 150MHz of bandwidth giving 1m resolution on the ground1. Bright Spark transmits 3750 MHz giving 4cm resolution on the ground! This is finer than any military system out there (that we know of).
Military or Scientific ?
Over recent years there has been an explosion of low cost RF electronics that has increased the accessibility of sophisticated radar signal processing techniquess. Unfortunately the cost of flying high fidelity SAR sensors is still quite prohibitive for most Universities and research institutions. The combination of these two has resulted in an increase in RF engineering expertise within the scientific community and a limited ability to apply those skills to real-world data.
As one of Dstl’s responsibilities is to facilitate scientific advances it has adopted an unusual approach to alleviate this problem. Rather than lock away the Bright Spark data in highly classified vaults, it has worked with decision and policy makers across the British Government to agree that the imagery is not classified unless the area being observed contains sensitive information. For this reason we are pleased to offer availability of limited Bright Spark datasets to the scientific community.
Table of Specifications
|Centre Frequency||34.2 GHz|
|Centre Wavelength||0.00876316 m|
|Number of Linear FM Chirps||3|
|Bandwidth of each chirp||1.32 GHz|
|Chirp step||1.2 GHz|
|Total bandwidth||3.72GHz (1.32 + 2*1.2)|
|Slant range resolution||0.04m|
|Cross range resolution||0.028m|
|Image sample size range||0.037594m|
|Image sample size cross range||0.037594m|
|Range oversample factor||1.33|
|Cross range Oversample factor||1.33|
- The Data tab is where you can find out about the images available to download and how you can access the raw data.
- Have a look under articles to see papers and documents related to Bright Spark.
If you want to help, add an article, submit a paper of have a question about the data then please feel free to send me an email.
This project would not have occured without the support of key individuals in Thales and Dstl. In addition there are a lot of people around the world actively supporting radar research and the aims of this project. Here is a growing list of active participants. If you have something to contribute to the work then drop me a line and Ill add your name to the list.