Technical Reports of the Ins�tute of Cetacean Research (2021)

pp. 64–67

Technical Report-Note (not peer reviewed)

Development of an Unmanned Aerial Vehicle (UAV) and u�lity forthe research work of the Ins�tute of Cetacean Research
Koji Matsuoka* and Takashi Yoshida
Institute of Cetacean Research, 4–5 Toyomi-cho, Chuo-ku, Tokyo 104–0055, Japan*Contact e-mail: matsuoka@cetacean.jp
The usage of drones is increasing for the observa�on andresearch of wild animals including the cetaceans. Drones
are replacing helicopters and small airplanes which require
airﬁeld for departure and arrival. The key characteris�cs ofdrones are their small sizes and maneuverability. Furthermore, they can be operated from the pla�orm of vessels.
This increases their u�lity in diﬃcult environments that areo�en encountered in cetacean research ac�vi�es. Whale
research using drones has already begun (e.g., Hodgson
et al., 2017), and they are used for various observa�on purposes in the polar regions (e.g., Funaki et al., 2014).
The Ins�tute of Cetacean Research (ICR) has acquired
some commercially-available drones, e.g., the Phantom
4 Pro (DJI), with the aim of studying whales. Also theICR has started the development of its own Unmanned
Aerial Vehicles (UAVs). This technical note describes thisdevelopment, and summarizes the applica�on of UAVs
in the context of the research work on cetaceans by theIns�tute.
UAV development at the ICR
Since 2019, the ICR has been working on the development of new whale research methods for cetaceansusing small UAVs. It has developed a Ver�cal Take-oﬀ andLanding (VTOL) type UAV, speciﬁcally to operate from acetacean research vessel. Flight tests in open seas fromseveral oceanic regions, including the Antarc�c Ocean,
have been conducted to examine the performances of
the UAVs. From such tests, and to ensure good performance, several important factors were iden�ﬁed. Amongthese factors were strong winds at open sea, hull swaying, magne�c disturbance and radio wave interference,

Table 1
Speciﬁca�on of the newly-developed VTOL-UAV in 2021.
Name

Prototype ASUKA Mk 4

Overall length

1,920 mmWing length

2,500 mm

Overall height

620 mmBody weight

12.44 kg

Cruising range

Approx. 100 km (51 km in Level 3 ﬂight mode)

Maximum speed

160 km/h

Payload5 kg maximum

Seaworthiness

Figure 1.
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Normal opera�on at 20 kt wind speed, level ﬂight maintained at 40 kt wind speed

Photograph of the VTOL ASUKA aircra� (Prototype ASUKA Mk 4) developed in 2021.

Development of an Unmanned Aerial Vehicle (UAV) and u�lity for the research work of the Ins�tute of Cetacean Researchand geomagne�c devia�on in the polar regions. The newUAV ʻASUKA,ʼ a VTOL type, was designed to minimize allsuch detrimental factors. The main data of the ASUKA are
shown in Table 1 and the UAV itself is shown in Figure 1.
Figure 2 is a conceptual image of the opera�on ofVTOL-ASUKA from the pla�orm of a cetacean research
vessel in the Antarc�c. No airﬁeld is required as the UAV
can depart and return using the pla�orm of a cetacean
research vessel conduc�ng rou�ne line transect surveys.
Flight opera�ons can be conducted in shallow waters
and ice bound seas where research vessels are unable toenter.
UAV performance during a ﬁnless porpoise survey
The ASUKA was used in a survey for ﬁnless porpoise(Neophocaena phocaenoides) in Mikawa Bay, Aichi prefecture in March 2021. The UAV departed and arrived
using the pla�orm of the research vessel and conducted

a total of six aerial visual surveys (total distance: 71.2 km).
It succeeded in detec�ng and iden�fying three ﬁnless
porpoise pods (four individuals). The sigh�ng rate was
0.56 individuals/10 km. Figure 3 shows the ASUKA operating during the ﬁnless porpoise survey in Mikawa Bay on
29 March 2021.
In March 2021, ASUKA achieved an autonomous ﬂight
distance of 51 km in the North Paciﬁc Ocean (Figure 4,le�), which is considered a Japanese record for UAVs (adomes�c record for ﬂight distance under the condi�onsof Level 3 ﬂight (unmanned area with no visual line ofsight and no assistants) as speciﬁed in the ʻRoadmap for
the Industrial Revolu�on in the Skyʼ promoted by Japan.
Figure 4 (right) shows the track lines of the UAV during
the ﬁnless porpoise survey in Mikawa Bay on 29 March
2021. Figure 5 shows ﬁnless porpoise detected and iden�ﬁed by the ASUKAʼs camera.

Figure 2.

Conceptual image of the opera�on of VTOL-ASUKA from the pla�orm of a vessel. Unlike small airplanes
and helicopters, ASUKA do not require an airﬁeld, and can operate over shallow waters as well as in polynyas in the Antarc�c where the vessels cannot operate. In coastal areas, ASUKA can provide informa�on on
the presence of ﬁshing nets.

Figure 3.

VTOL-ASUKA undertaking ver�cal take-oﬀ from the research vessel (le�) and launch landing on the vesselin strong winds (right) during a survey in Mikawa Bay on 29 March 2021.
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Technical Reports of the Ins�tute of Cetacean Research (2021)

Figure 4.

Long-distance (51 km) survey trial (le�) and track lines of the survey (right) by ASUKA during the ﬁnless
porpoise survey in Mikawa Bay on 29 March 2021.

Further improvement
Further performance development of ASUKA con�nues
to be focused on aspects related to shoo�ng equipment
and image processing technology. The eﬀorts will also befocused on increasing the dura�on of surveys (distances)by the crea�on of a lightweight vehicle with a large capacity ba�ery. The idea is to further develop and implement an UAV capable of carrying out research on marinemammals under stringent condi�ons, while ensuring that
disturbance to the animals is minimal.

Figure 5.

Photographs of ﬁnless porpoise taken during aﬂight at an al�tude of 50 meters by ASUKAʼs camera(using zoom) during the ﬁnless porpoise survey inMikawa Bay on 29 March 2021.

Japan 2021 Drone Exposi�onThe ASUKA was introduced at the Japan 2021 Drone Exposi�on for the Commercial Unmanned Aircra�s Systems(UAS) Market, together with its results from aerial cetacean surveys. The exposi�on was held between 14 and16 June 2021 at the Makuhari Messe (Chiba City, Japan),and was organized by Japan UAS Industrial Development
Associa�on (JUIDA). During the event, ASUKA a�ractedthe a�en�on of many engineers as an aircra� capableof taking oﬀ and landing from vessels. During the Exposi�on, useful informa�on was obtained regarding, forexample, the development of technology for moun�ng
biopsy equipment as well as surveys on marine debris
and red �de. Such advances will be useful for research on
cetaceans.

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Applica�on to the study of cetaceans at the ICR
The ICR regularly conducts vessel-based dedicatedcetacean surveys. In general, UAVs operated from thepla�orm of the vessels will increase and improve theobserva�onal capacity during the surveys. For example,
the use of UAVs will allow the survey of cetaceans even incircumstances where vessel movement is inhibited, suchas the polynyas in the Antarc�c.
The use of UAVs will also complement the observa�onsof researchers on board regarding species iden�ty, number of animals in a school and behavior of the sighted
cetaceans. UAVs can also obtain data for photogrammetry studies, which are important for taxonomical or stock
structure studies.
Addi�onally, the use of UAVs will enable the collec�onof environmental data from above when opera�ng overshallow waters, as well as the detec�on of areas whereﬁshing gears are installed. That is, it is an�cipated thatthe use of drones will enhance informa�on collec�onfrom a wider range of oceanographic condi�ons and sea
areas, thus providing more precise ﬁndings from researchac�vi�es.

Development of an Unmanned Aerial Vehicle (UAV) and u�lity for the research work of the Ins�tute of Cetacean ResearchACKNOWLEDGEMENTS

REFERENCES

We thank the Fisheries Agency of Japan for researchpermit and funding for the development and implementa�on of UAVs. We also thank Yoshihiro Fujise, Takashi
Hakamada, Megumi Takahashi, Taiki Katsumata andMasato Hayashi (ICR) for their logis�cal support. Ourgra�tude to all engineers who were involved in the development work. Finally, our thanks to Luis A. Pastene (ICR)
for his assistance in the prepara�on of this manuscript.

Funaki, M., Higashino, S., Sakanaka, S., Iwata, N., Nakamura, N.,
Hirasawa, N., Obara, N. and Kuwabara, M. 2014. Small unmanned aerial vehicles for aero-magne�c surveys and theirﬂights in the South Shetland Islands, Antarc�ca. Polar Science
8: 342–356.
Hodgson, A., Peel, D. and Kelly, N. 2017. Unmanned aerial vehicles for surveying marine fauna: assessing detec�on probability. Ecological Applications 27 (4): 1253–1267.

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