4.5.2. Disadvantages

Processing and analysis of aerial photographs require experienced technical manpower.

To effectively process and analyze aerial photographs, professionals must have specialized training and experience. This requirement can limit the availability of skilled workers and increase project costs. Involving inexperienced personnel might lead to mistakes or inaccuracies in interpreting the photographs.

Think of it like flying a plane. To fly an airplane, you need trained pilots who understand navigation, weather conditions, and aircraft operation. Just like untrained individuals should not fly a plane, untrained personnel should not analyze aerial photographs, as this can lead to flawed interpretations.

Photographic coverage requires advance flight planning as well as specialised equipment and aircraft.

Taking aerial photographs is not as simple as flying an aircraft. It requires meticulous planning to ensure the right equipment is used, and the flight is optimized for the area being photographed. This includes considering factors such as the flight path, altitude, and timing to avoid weather-related issues.

Consider planning a road trip. You wouldn't just hop in your car and start driving anywhere; you'd map out your route, check the weather, and prepare your car. Similarly, aerial photography necessitates careful preparation to be effective and useful.

Atmospheric conditions (winds, clouds, haze, etc.) may affect the flight plan as well as quality of aerial photographs.

Weather plays a significant role in aerial photography. Strong winds can make flying difficult or unsafe, while clouds and haze can obscure the ground, leading to poor-quality images. Because of this, photographers must time their flights according to weather forecasts, which can complicate planning.

Imagine trying to take a clear photo of a beautiful landscape during a storm. Rain and clouds would obscure your view, just like they can harm the quality of aerial photographs. Photographers need to wait for clear skies, similar to waiting for a sunny day to take photos outside.

Seasonal conditions, i.e., snow cover will affect the photographs and obstruct the features.

Certain seasonal conditions, like snow, rainfall, or vegetation growth, can obscure the features that one would want to map or analyze. For instance, snow can hide roads or landmarks, making it difficult to interpret the landscape accurately.

It’s like trying to find your driveway under a thick layer of snow. Just as you cannot see the ground features clearly in winter, aerial photographs taken during snowy periods will have similar obscured visibility, complicating analysis.

The ground information hidden by high-rise buildings or dense tree canopies, and roads hidden by trees on both sides, cannot be mapped accurately.

Aerial photography can struggle to provide useful information where there are obstructions like tall buildings or dense forests. These objects can obscure the view of the ground, preventing accurate mapping and analysis of what lies beneath.

Imagine standing in front of a large wall and trying to see what’s behind it. Even if you have a telescope, if the wall is too high, you won’t be able to see through. Similarly, aerial photos cannot effectively show what is hidden behind tall trees or buildings.

Accuracy of contours and cross sections will depend on the accuracy of 3D models generation from stereo-photographs which is a factor of scale of photographs and number of ground control points (GCPs) used for creating the 3D model.

The precision of any measurements or maps derived from aerial photographs is contingent on the quality of the 3D models created from them. This model accuracy depends on the scale of photographs taken and the number of ground control points used for calibration. If these factors are not optimal, it can lead to inaccuracies.

It’s comparable to assembling a jigsaw puzzle. If you don’t have the right pieces or if they are incorrectly cut, the final picture will be flawed. In the same way, if the aerial photographs and ground control points aren’t accurate, the resulting 3D model will also be inaccurate.

Aerial photography is expensive for developing countries, like India, particularly if repetitive coverage of an area is required for large scale mapping and monitoring purposes.

For developing countries, the financial burden of deploying aircraft and technology for aerial photography can be considerable. This is especially true for projects that require repeated photography of the same area over time for monitoring purposes. Limited budgets can make consistent monitoring and mapping challenging.

Think of it like hiring a professional photographer for an important event. If your budget is limited, it might be hard to hire someone on a regular basis for annual occasions or events. Similarly, developing nations face constraints that impact their ability to consistently acquire aerial photography for needs like urban planning or environmental monitoring.

For sensitive areas or restricted areas, aerial photography may not be allowed.

Certain areas, such as military zones or places that require protection for privacy or security reasons, may be off-limits for aerial photography. This restricts the ability of those who need to collect data or conduct studies in such locations.

Consider a no-fly zone over a military base. Just like how commercial flights cannot operate in such areas, aerial photographers are also unable to gather data from restricted zones, which can hinder thorough surveying in sensitive regions.

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