The ESA POLinSAR Workshop on "Applications of SAR Polarimetry and
Polarimetric SAR Interferometry" is arranged at the ideal time
for developing this urgently
required technology for environmental stress-change and
local-to-global conflict monitoring in
air and specifically in space. In this overview, reasons are provided on why we do need to place
multi-modal, multi-band single and multiple pass
POLinSAR monitoring platforms into space.
The questions "on what POLinSAR
monitoring can provide that POL-SAR and IN-SAR by
themselves cannot accomplish" is assessed; whereupon facts and justifications
on placing POL-IN-BISAR satellite clusters into space are
presented. Reasons for this technology becoming a
basic requirement for current, near-future and much more so for future all-day & night
year-round monitoring of the terrestrial
covers are analyzed in view of the un-abating and
uncontrollable terrestrial population explosion. The pertinent
questions on how to reduce the
exorbitant cost for initiating this
"home-globe security protection" technology are also broached,
and the expected benefits are laid out in detail. The
pertinent National and International airborne
and space borne multi-modal, multi-band SAR remote
sensing and security conflict surveillance
support agencies are herewith invited for co-sponsoring
our proposal, which is timely and
POLinSAR platforms are urgently required to be placed into space.
I. Background with developmental technology history
1.1. POLinSAR theory and algorithm development has been accomplished and is verified.
1.2. POLinSAR image data takes were acquired with space borne SIR-C/X-SAR and with
several POLinSAR airborne platforms like the DLR-OP-IHR E-SAR, the DCRS EMI-SAR,
the CRL PiSAR, the ONERA RAMSES-SAR and the NASA-JPL AIRSAR.
1.3. POLinSAR image feature sorting and identification algorithms have been tested and are
available as was demonsrated by Cloude and Papathanassiou beyond doubt.
1.4. Cost reduction with the aid of bistatic cartwheel POL-SAR imaging platforms in air and
space have been and/or are being demonstrated currently in North America and Europe.
II. From airborne to space borne POLinSAR platform deployment
2.1 Not withstanding space borne applications, airborne multi-modal, multi-band POLinSAR
test platform development is essential, must go on for years to come in order to support
basic technology advancement and algorithms verification
2.2 Airborne POL-inSAR platform deployment, while truly imperative for technology
development, is too expensive for wide area conflict monitoring, and need be replaced by
"Unmanned Automated Vehicle: UAV" POLinSAR platforms at the same time during
which the entire air and space borne technology is being developed
2.3 While both airborne and UAV multi-modal, multi-band POLinSAR platform
deployment is very essential for localized, regional and mission-oriented flight-path
imaging; global terrestrial and future planetary remote sensing and surveillance require
the urgent and rapid development of space borne multi-modal, multi-band single and
multiple pass POLinSAR monitoring platforms
2.4 Global worldwide monitoring of the terrestrial hydro-sphere and biosphere together with
a more accurate acquisition of more precise biomass estimation require single and
distributed multi-modal, multi-band POLinSAR monitoring platform deployment. This
technology will become all the more relevant for effective global conflict surveillance
III. Applications and improvement on terrestrial biomass estimation
3.1 POL-SAR imaging platform deployment enabled the development of highly improved
supervised and unsupervised image feature sorting and interpretation algorithms
including soil moisture and roughness parameter estimation, which are far superior to
those of mono/multiple-polarization-amplitude SAR and/or passive lidar sensing.
3.2 IN-SAR can provide only average-in-altitude "Digital Elevation Maps: DEM" and it is
not able to discern canopy cover versus under-store, versus vegetated ground and/or
multilayered under burden returns.
3.3 Although for rather specific limited cases multiple complex amplitude-only (HH, HH +
VV, HH + HV, VV + VH) quasi-polarimetric SAR may provide may provide improved
"specific scenario-dependent" information on vegetation cover above that of amplitude-
only SAR, it is not sufficient for precise biomass estimation of densely vegetated and
especially forested regions; whereas INSAR does not help at all
to acquire 3-D forest canopy versus forest under-store, versus vegetated ground und
multi-layered under-burden differentiation, which only and only multi-band single and
multiple pass POLinSAR and POL-TOMO-SAR can accomplish. This applies especially
to soil moisture and roughness estimation as well as to the mapping of flooded regions.
IV. Cost reduction via POLin BISAR cart-wheel clusters in space
4.1 It is a well known fact that any novel advanced forefront
imaging technique whether in
non-destructive testing, medical radiology, sub-aquatic sonar imaging, and/or
Radar/SAR remote sensing and conflict surveillance - is exorbitantly costly during its
infant stages; and these relatively high cost factors cannot and must not be considered a
deterrent factor, hampering the steady and urgent advancement of POLinSAR technology.
4.2 Multi-modal multi-band polarimetric SAR deployment was proven a viable novel
imaging technology hitherto not surpassed or even closely competing with existing
SAR imaging technology. In fact, it was demonstrated beyond doubt that fully
polarimetric POL-SAR outperforms conventional mono/multiple-polarization-amplitude-
only SAR by a factor of 12 15 dB in general.
4.3 Airborne and space borne POLinSAR imaging & sensing platform deployment was
successfully demonstrated with the SIR-C/X-SAR missions 1 & 2, which were
complemented more recently by the DLR-OP-IHR multi-pass E-SAR POL-TOMO-SAR
experiments, providing the first true 3-D image-reconstructions of volumetric vegetation
scatter, which when extended to the multi-band microwave POLinSAR image data take
acquisition will enable the isolation of compact (point) targets in a 3-D forest and
vegetated or urban environment being of essential relevance to `National home-land'
and even more so to `International home-globe' security conflict surveillance missions
4.4 The first steps in developing airborne and space borne clusters of partially and fully
polarimetric bistatic cartwheel SAR imaging deployment are well under way both in
Europe and North-America and, a fully polarimetric Cartwheel SAR Cluster
deployment was proven to be feasible - at least on the drawing boards. The costs are only
slightly above those of purely amplitude-only systems, and the truly impressive
improvements obtained in deploying bistatic POLinSAR cart-wheel clusters for a highly
more accurate and close-to-reality biomass estimation justify the costs.
V. Benefits for highly improved and more accurate biomass
estimation, and for the ` homeland'
plus `home-globe' security conflict mitigation missions
5.1 Near future and future environmental stress-change remote sensing and localized to wide
area security conflict surveillance requires monitoring technologies which are being
advanced towards the limits of physical realizability like POLinSAR is
5.2 The entire field of local to global biomass estimation of multi-modal, multi-band
microwave POLinSAR imaging in concert with advanced passive and active polarimetric
EO sensing will be advanced most actively and will become quantitatively accessible.
5.3 The initial exorbitant cost factors are being addressed
and shown to be not as drastic -
with the introduction of multi-static cartwheel clusters of multi-band POL-SAR, i.e.,
POL-IN-BISAR systems - as previously estimated, which will pave the way to "all-day
& night year-round" 3-D monitoring of the terrestrial covers.
5.4 Similar to placing the equidistantly spaced fleet of
orbiting GPS satellites into space, we
are herewith developing the complementary set of equidistantly spaced orbiting clusters
of multi-modal, multi-band microwave POL-IN-BISAR monitoring satellites for space
deployment, which will provide day and night, hourly stress-change and security conflict
indicators. These all-important indicators are required already now, and much more so
are in desperate need in the nearer and distant future for protecting "Mother Earth = our
home-globe" suffering from an un-abating population explosion and therewith an ever
increasing number of future environmental stress-change and political security conflicts.