ieijing 2008
1201
TOWARDS A NEW PARADIGM FOR HIGH-RESOLUTION LOW-COST
PHOTOGRAMMETRYAND REMOTE SENSING
I. Colomina, M. Blâzquez, P. Molina, M.E. Parés and M. Wis
Institute of Geomatics
Generalität de Catalunya & Universität Politècnica de Catalunya
Parc Mediterrani de la Tecnologia
Av. del Canal Olimpie s/n, Castelldefels, Spain
ismael.colomina@ideg.es
KEY WORDS: calibration, INS/GPS, orientation, photogrammetry, remote sensing, trajectory determination, UAV.
ABSTRACT:
Current mobile primary data acquisition systems can be grouped in three main categories: terrestrial, manned airborne and satellite
borne. This paper discusses whether Unmanned Aircraft Systems (UASs) together with the appropriate sensing and navigation-
orientation payloads can constitute a new, fourth data acquisition paradigm of the high-resolution and low-cost type. For this purpose,
and based on practical experience gained at the Institute of Geomatics (IG), some fundamental issues of UAS-based photogrammetry
and remote sensing (PRS) are reviewed; from the geomatic aspects of navigation and orientation, to the manifold of already existing
applications and to various regulatory initiatives that the main aviation authorities are conducting. The paper identifies technical
challenges and advantages specific to UAS-based PRS and concludes that, beyond the technical aspects, one key issue is the
integration of UAS in the civilian non-segregated airspace.
1. INTRODUCTION
A typical UAS consists of an Unmanned Aircraft (UA), a
Control System (CS) —usually a Ground Control System
(GCS)— and a communications data link between the UA and
the CS. In civilian applications, the vast majority of UAs are
equipped with sensors and perform some form of remote
sensing. The term and concept of UAS have been recently
introduced to replace those of Unmanned Aerial Vehicle (UAV)
which is just a component of an UAS.
UAs can be categorised in terms of weight, altitude and range,
and other criteria. According to weight we have micro UAs
(less than 2kg), mini UAs (2 to 8 kg), small UAs (8 to 25-30 kg)
and tactical UAs (25-30 to 400 kg). Figure 1 shows an example
of a small UA for PRS applications. (Sometimes, UAs
weighting less than 150 kg are also referred to as small UAs.)
According to altitude and range we have Low Altitude Long
Endurance UAs, Medium Altitude Long Endurance (MALE)
UAs (5.5 to 18 km), High Altitude Long Endurance (HALE)
UAs (above 18 km) and others. UA classification is of the
utmost importance for worthiness and certification issues and a
current hot topic in the aviation community. The above
categories are not comprehensive, given just for the sake of
clarity and may easily change in the next months.
communications, advertising, media, audio broadcasting and
meteorology.
Requiring no on board human pilots has advantages and
disadvantages. The fundamental advantage of UASs is that
they are not burdened with the physiological limitations and
economic expenses of human pilots. As a result, UAs use to be
cheaper, smaller and lighter than their manned siblings. UAS
operations are therefore far less expensive (20-30 /hr for a 10
kg payload) than any manned aircraft and far more
environmentally friendly (generate less C0 2 and noise).
Furthermore, there are areas and circumstances where manned
aircrafts cannot be flown and where unmanned systems can,
like low altitude flights.
The fundamental disadvantage of UASs is that they do not
benefit from the sensing and intelligent features of human
beings and, therefore, they are less able to react to unexpected
situations. Mainly because of this, the usage of UASs is not yet
sufficiently regulated by the civil aviation and security
authorities. This is a major barrier to the development of the
UAS natural market. Other, derived, issues are those related to
communication links (reliable, long range, low weight, out of
line-of-sight, sufficient bandwidth), collision avoidance and
homeland security.
UASs date back to the 19th century and modem UASs date
back to the Second World War. Historically, UASs have had a
strong military presence for scouting and attack missions since
their use in the battlefield involves no risk of loss of human life.
The dominant role of the defense and espionage industry
notwithstanding, the civilian applications and their overall use
have expanded dramatically over the past years. The statement
can be easily proven by a quick Internet web search. Among
their many uses, we can mention Earth observation and aerial
surveying, precision agriculture, environment monitoring and
sampling, general scientific research, surveillance,
The above mentioned advantages and the availability of the
Global Positioning System (GPS), together with the
unstoppable miniaturization of computer and sensing
technology, have calledthe attention of many professional
communities to the use of UAS. In this paper we explore the
feasibility of high-resolution airborne PRS with UAS.