Resource Centre‎ > ‎

Devices to capture Images

This page provides an overview about the different means to capture images from above and compares the means according to different criteria, so we can have a better understanding of the advantages and limitations of our own system. A conclusion is drawn concerning the use of each device in a Disaster Situation, summarised in a comparative table.

Means to gathers photos from above

Unmanned Means

Unmanned platforms are very variable in their technical specifications. The requirements for lifting capability and platform safety are much less stringent with unmanned than with manned platforms; the cost and technical expertise needed to operate such systems also vary greatly.

Poles or Masts and Telescopic Arms
Mainly used in Media and sometimes in Civil Protection, they are also used for taking photos of houses for real estate listings or on archaeological sites. From a limited hight, the cameras are triggered electronically from the ground.

The low cost approach means that the methods should be available to nearly any researcher or technician in specific domains. User friendly, the system doesn' t require specific knowledges. Good manoeuvrability. The resolution and interpretation of the image is very good, the idea being simply to have a flying-like point of view. The range is limited by the low-hight which excludes Poles or Telescopic Arms from their use in other field of activities.
Conclusion: little use in catastrophes.

Kites, Balloons, Blimps (Dirigibles)
-Kites are tethered aircraft lifted by wind. 
Kytoon is a type of kite filled with hydrogen, hot air, methane, or helium. Both Kites and Kytoon being limited by weather condition are rarely used in Aerial Photography.
Balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. If the balloon is tethered to the ground is called a moored balloon. Balloons are often shaped like blimps or Zeppelins but have no propulsion.
-Blimp & Zeppelins. The term "blimp" refers only to free-flying aircraft. A blimp or non-rigid airship, is an airship without an internal supporting framework or keel. Distinction is made between non-rigid airship, semi-rigid airship and rigid airship (e.g., a Zeppelin).
source: Wikipedia)

  • Unmanned Hot Air Moored balloon (type of aerostat) - fixed on a line (tethered)
  • Unmanned Moored balloon (type of aerostat) filled with Helium without engine - fixed on a line (tethered).
  • Unmanned Hot Air Balloon (free flying balloon) with engine to propeller and steer it through the air. (no examples found).
  • Unmanned Blimp (Dirigible) is a free flying aircraft filled with Helium and has usually an engine to propeller and steer it through the air.
Camera and Robot system of unmanned moored balloons, blimps (dirigibles) and Zepellins are usually remote controlled to take Aerial Photos. Unmanned Blimps (free-flying aircraft) are normally manoeuvred by radio remote control as well as the camera and robot system. They are frequently used in different Aerial Photography areas such as tourism, agriculture or urban planning (see Applications for aerial photographies). Depending on camera and software used, the imagery has good resolution which allows good interpretation of the Photos. 
However, specific formation is required to use equipment and for the interpretation of Aerial Pictures.
Conclusion: The user-friendliness and the cost effectiveness of those systems, especially the unmanned moored balloon, the easy transportation and manoeuvrability, the real time utilisation and the direct interpretation of the material produced are clear and direct advantages when applied in Disaster and Emergency situation. However the tethered version have limited activity radius and force to move on the ground.

Unmanned Air Vehicles (UAVs), Drones, Micro Air Vehicles (MAVs)
An unmanned aerial vehicle (UAV) is an aircraft that is flown by a pilot or a navigator, without a human crew on board. They have been developed for military purposes since the first World War. However the technology has improved a lot resulting in an increase in civil applications. Most of the UAVS utilise a variety of wings, blades, rotors and fins to create lift and/or stabilise the vehicle in flight. Today's UAVs often combine remote control and computerised automation. More sophisticated versions may have built-in control and/or guidance systems to perform simple scripted navigation functions such as way-point following to make Aerial Photos. Nevertheless the autonomy of the system determines the number of applications.
Conclusion: The UAVs are certainly the future in Aerial Photography but so far due to the high technical requirement (e.g the manoeuvrability) their use in Disaster and Emergency Situation is limited to big scale catastrophes in
countries with high economical resources.

Manned Means

Manned platforms are very variable in their technical specifications. General requirements such as infrastructure, cost and technical expertise needed to operate such systems and legislative framework make manned means much more stringent than unmanned ones. The use of manned means is fairly expensive to operate and normally requires a trained pilot, ground-support crew and infrastructure (e.g. for starting and landing). It exists a great variety of devices used in Aerial Photography.

Parachutes, Paraglider, Hang glider, Ultralight, Gliders
This group is "pro-forma" mentioned, being a manned mean. Lightweight, slow-flying aeroplanes and gliders are subject to minimum regulation being mainly used for leisure and sporting purposes.
Conclusion:To our knowledge they are not used in disaster situations.

Balloons, Blimps and Zeppelins
The categories manned balloons and Zeppelins are as numerous as the unmanned versions but have no special role in Aerial Photography compared with their normally smaller unmanned relatives. 
Conclusion: H
igh technical requirement, physical infrastructure and regulating framework limits its use in disasters and emergencies.

Helicopters, Fixed-wing Aircrafts, Airplanes
These aircrafts are flying just like the unmanned version. They move with moderate to high velocity and vibrate. Velocity and vibration has an impact on the quality of the photos requiring a professional camera system.
Their use in Aerial Photography cover the whole range of application (see: Applications for Aerial Photography
Conclusion: These are usual devices used in Emergency Situation, but the high cost and the low availability (most of the cases they are needed for transport purposes of wounded or live saving material) limit their use for taking Aerial Photos.


Satellites are used for a large number of purposes. Common types include military and civilian Earth observation, communications, navigation, weather, and research satellites. Satellites are usually semi-independent computer-controlled systems.
Reconnaissance satellites are Earth observation satellite or communications satellite deployed for military or intelligence applications (Very lit
tle is known about the full power of these satellites, as governments who operate them usually keep information pertaining to their reconnaissance satellites classified.)

Earth observation satellites are intended for non-military uses such as environmental monitoring, meteorology, map making etc. (Source: Wikipedia)

Satellite in Disaster Situation
An International Space Charter has been put in place aiming at providing a unified system of space data acquisition and delivery to those affected by natural or man-made disasters through Authorized Users. Each member agency has committed resources to support the provisions of the Charter and thus is helping to mitigate the effects of disasters on human life and property. 
Activation Mechanisms of the Space Charter:
The only bodies authorised to request the services of the Charter for a disaster occurring in their country or territory are the Authorised Users (around 40). An Authorised User may request the Charter to assist a disaster management user from another country in response to a major emergency. (Source:International Space Charter)

In the framework of the Space Charter, it seems that a cooperation, or a kind of complementation between data acquisition of satellite and Aerial Photography is not integrated.

Advantages of Satellite Images in Disaster Situation:
They can provide a rapid and accurate overview of a disaster situation of large geographical dimension. They can also provide data on "no go" areas such as disasters occurring in the territory of authoritarian states where access is restricted. 

Weaknesses of Satellite Images in Disaster Situation:
Different problems can be pointed at, concerning the acquisition, provision and interpretation of Satellite Images:
-Meteorological issues such as clouds can delay the data acquisition and delivery.
-Satellites Images have to pass through a Value Added Reseller for the correct interpretation and then sent to End Users. 
-Availability of Satellite Images for remote places, small scale disasters or updated images for long ongoing disasters with frequent changing situation (such as reconstruction after an earthquake) seems to be limited.
-Delivery to an Onsite Coordination Centre/Crisis Management Centre can be sometime very difficult, depending on satellite connection and bandwidth.
-The resolution of Satellite Images can limit its use in disaster response. In a situation where detailed information about a location and Real-time Use is required (such as images of buildings for Urban Search and Rescue teams in an Earthquake scenario) Satellite Images are not sufficient.
-Most of the Satellite Images are taken vertically which prevent topographical (3D) interpretation.
-No real-time use

ConclusionConcerning the images used in disasters and other application areas, satellites play a significant role in large scale disasters with a wide geographical impact. Satellite Images provide valuable information in disaster situation. Sometimes they are the only way to retrieve information and therefore international pressure can be built up on authoritarian regimes. 
Relying on the production and the provision of Satellite Photos can generate delays, time can be wasted and life endangered. In some disaster scenario, Aerial Photos have clear advantages and Satellite Images are not the mean of first choice. Nevertheless Aerial Photos can complement Satellite Images ( for instance if Satellite Images are not complete due to clouds or other weather conditions and there are some doubts in the interpretation of the images, confirmation can be done with Aerial Photos).

Comparison of the different Devices Systems when used in a disasters:

The comparison table provides an overview of the different devices (technologies) applied in the case of Natural or Man Made Disasters and Hazards. The criteria used derive from international acknowledged evaluation criteria in Humanitarian Action. The criteria are modified with the purpose to compare devices (technology) to take images from disaster zones. The comparison encounters various problems such as the moment of the use of the device and the magnitude of the disaster or hazard as well the resources available in the concerned country. For the purpose of simplification we are using the scenario of a common natural disaster such as an earthquake or flooding in a developing country and looking at the criteria from the perspective of a user of images located in the disaster zone. In this scenario we assume the Space charter is activated and Satellite images are free available.

Definition of the criteria used in the comparison table:

Relevance /Appropriateness:
Relevance is concerned with assessing whether the device (technology) is in line with local needs and priorities.
A device (technology) is appropriate when it can be used themselves by local teams, increasing ownership, accountability and cost-effectiveness accordingly.
Sub Criteria Relevance /Appropriateness: Availability, User friendliness, Technical Autonomy, Affordability/Sustainability

Connectedness refers to the need to ensure that updated Imagery is available during all phases of the disaster management cycle, including to a context that takes longer-term and interconnected problems into account.
Sub Criteria Connectedness: Availability , Affordability/Sustainability, Real-time Use,

The need to produce images in order to support planning and coordination process of interventions to reach major population groups facing life-threatening suffering wherever they are.
Sub Criteria Coverage: Quality, Accessibility,

Efficiency measures the outputs (Imagery used in planning and coordination) – qualitative and quantitative – achieved as a result of inputs. 
Sub Criteria Efficiency: Quality, Technical Autonomy, Affordability/Sustainability,

Effectiveness measures the extent to which the taking of the images achieves its purpose (support to planning and coordination), or whether this can be expected to happen on the basis of the outputs. Implicit within the criterion of effectiveness is timeliness.
Sub Criteria Effectiveness: Real-time Use, Interpretation, Quality, Availability

Impact looks at the wider effects (influencing decision making processes) of the images taken. Impacts can be intended and unintended, positive and negative, macro (sector) and micro (household).
Sub Criteria Impact: Quality, Real time Use

Definition of the Sub critera:

User friendliness: User friendliness describes the handling of the device and the outputs (images) to support planning and coordination by a Disaster Management Team on the spot of a disaster zone (On-Site).

Interpretation: Interpretation looks at the possibility to understand the information captured in an image and attribute the correct use of it.

Availability: Availability describes the possibility in which a device or its product is available at all stages of the planning and coordination process and on site of the disaster.

Affordability/Sustainability: Affordability looks at the possibility that device and its product are available to local emergency management teams and that they can maintain the device and equipment.

Real-time Use: Real-time use describes the ability to produce, provide and make an interpretation of images at the same moment.

Technical Autonomy: Technical Autonomy describes the circumstances in which images are captured, delivered and processed independently from human and technical inputs.

Quality: Quality describes resolution of a photo, 3 D impression.

Accessibility: Accessibility describes the geographical range of the image and the autonomous manoeuvrability of the Device.