DR. RUSSELL KEITH RANEY
For over four decades, Dr. Russell Keith Raney has been one of the most distinguished
pioneers of Synthetic Aperture Radar (SAR) systems and techniques.
Dr. Keith Raney is widely known as the first proponent of Digital SAR processing when at the
time all experts were of the view that optical processing was the only feasible way. He
brought out the first Digital SAR processor under the aegis of Canada’s MDA for SEASAT
SAR data (1978). Though the SEASAT processor used the classical Range Doppler
algorithm, he soon understood the fine limitations of this algorithm and proposed the Chirp
Scaling algorithm—together with colleagues from Germany and Canada—for simplifying and
improving the process for retrieving images from the data collected by the radar.
He was the inspiration behind the CCRS (Canadian Centre for Remote Sensing) radar
remote sensing programs. He was the principal architect of celebrated Radarsat-1 satellite.
The Radarsat series—Radarsats 1 and 2, followed by the Radarsat Constellation Mission
(RCM) —demonstrates that complex and costly SAR satellites can also be profitable and
support a wide variety of SAR data applications from commercial utility to climate change
In addition to this, he contributed to the design of Pioneer and Magellan, NASA’s Venus
orbital radars. Magellan demonstrated that one can cobble up a great interplanetary mission
from leftover hardware, enabled by new ideas such as Block Adaptive Quantisation. His
SAR-mode approach is the backbone of the European Space Agency’s first Earth Explorer
satellite Cryosat, a radar altimeter designed primarily to monitor changes in polar ice sheets.
Cryosat’s SAR mode altimetry has been adopted as the standard for international
operational oceanic radar altimeter missions such as Freilich and Sentinel-3.
Dr. R K Raney has connections to Indian Space Industry. He was the architect of the Hybrid
Polarimetric S-band Mini SAR payload of India’s Chandrayaan-1. This instrument delivered
evidence of water ice in the cold depths of permanently shadowed lunar craters. Before Mini
SAR, there were very few scientists—countable on fingers—who believed that there is water
at all on moon’s surface. After Mini SAR, the idea of water on the Moon has been accepted
One of Dr Raney’s significant contributions is the path breaking idea of Hybrid Polarimetry,
first flown in space aboard Chandrayaan-1 lunar mission (2008), which ISRO demonstrated
for the first time in Earth orbit with RISAT-1 (2012). This successful mission proved that full
polarimetry can be readily implemented in any SAR imaging mode, a major breakthrough.
Conventional Earth observing SAR full polarimetry uses the Quad-pol method (since 1985).
Quad pol’s unique mode yields impressive results, but is limited to low incidence angles, and
suffers from poor area coverage. As a result, Quad-pol products were never adopted by
operational agencies. In contrast, the Hybrid Polarimetry method has no such limitations,
hence this innovative approach operationalizes orbital radar polarimetry. Though his idea
was rejected by most SAR experts in its inception stages, Hybrid Polarimetry was
incorporated in Canada’s RCM following RISAT-1’s precedent, and today is on the path to
revolutionising polarimetric utility from orbital SAR systems.