Remote sensing is a method that collects data of the Earth's surface without causing disturbances. Thus, it is worthwhile to use remote sensing methods to survey endangered ecosystems, as the studied species will behave naturally while undisturbed. The latest passive optical remote sensing solutions permit surveys from long distances. State-of-the-art highly sensitive sensor systems allow high spatial resolution image acquisition at high altitudes and at high flying speeds, even in low-visibility conditions. As the aerial imagery captured by an airplane covers the entire study area, all the animals present in that area can be recorded. A population assessment is conducted by visual interpretations of an ortho image map. The basic objective of this study is to determine whether small- and medium-sized bird species are recognizable in the ortho images by using high spatial resolution aerial cameras. The spatial resolution needed for identifying the bird species in the ortho image map was studied. The survey was adjusted to determine the number of birds in a colony at a given time.

Landsat imagery is the most frequently used remotely sensed data in many fields related to the monitoring of the Earth's surface. As Landsat satellites have gathered data since 1972, lots of valuable information has been stored and can be derived from imagery over a long time interval. Of course, due to certain factors such as weather conditions and satellite-related technical issues, data collection cannot be consistent in time and space. Cloud coverage is the most obvious condition that determines the usability of a remotely sensed satellite images. For successful results, a rich data supply is essential. To explore the data supply of a certain study area, the Landsat metadata can be checked which is usually an involved process especially for a long time interval. Therefore, the visualisation of Landsat metadata can result in a faster work flow and successful study area selection. In this paper we present a cloud cover-weighted metadata map for the area of Europe.

The manuscript presents maps of internationally important wetlands located in the Kis-Sárrét (Hungary) from 1860 to 2008. The study area is located in south-east Hungary, in the Körös-Maros National Park and covers 8048 ha. For the historic map review, we used digitized data of topographic maps from the period of two military surveys and the Second World War. We also made habitat maps of the area in 2007 and 2008. Data processing, and the establishment of a database of the mapped area, was made using QuantumGIS 1.7.0 and Esri ArcView GIS 3.2. Maps were produced using Esri ArcGIS 10.0 and show where and in what ratio the once extensive wetlands occurred, how they changed and in which part of the area they survived in different mapping periods. They provide a point of reference for the monitoring of wetlands, contributing to the long-term conservation of these valuable habitats. Maps and diagrams show that between 1860 and 1944 wetland extent decreased by half. The ratio of natural, 'purely' wet habitats reaches only 4.67% now. Wetlands typically occur in habitat complexes, therefore not 'purely' wet habitats (20.77%) also have to be taken into account. Considering this, and a recent habitat reconstruction, the extent of wetlands is more favourable today than it was in 1944. However, to sustain them requires care and well-planned management to which the maps presented here provide an important basis.

Aerial surveys have always significantly contributed to the accurate mapping of certain geographical phenomena. Remote sensing opened up new perspectives in nature monitoring with state-of-the-art technical solutions using modern onboard recording equipment. We developed the technical background and the methodology that supports detailed and cost-effective monitoring of a network of natural areas, thereby detecting temporal changes in the spatial pattern of land cover, species, biodiversity, and other natural features. In this article, we share our experiences of the technical background, geometric accuracy and results of comparisons with selected Copernicus Land Monitoring products and an Ecosystem Map based on the testing of our methodology at 25 sites in Hungary. We combined a high-spatial-resolution aerial remote sensing service with field studies to support an efficient nature conservation monitoring network at 25 permanent sites. By analyzing annually (or more frequently) orthophotos taken with a range of 0.5–5 cm spatial resolution and 3D surface models of aerial surveys, it is possible to map the upper canopy of vegetation species. Furthermore, it allows us to accurately follow the changes in the dynamics at the forest edge and upper canopy, or the changes in species’ dominance in meadows. Additionally, spatial data obtained from aerial surveys and field studies can expand the knowledge base of the High-Resolution Aerial Monitoring Network (HRAMN) and support conservation and restoration management. A well-conducted high-resolution survey can reveal the impacts of land interventions and habitat regeneration. By building the HRAMN network, nature conservation could have an up-to-date database that could prompt legal processes, establish protection designation procedures and make environmental habitat management more cost-effective. Landscape protection could also utilize the services of HRAMN in planning and risk reduction interventions through more reliable inputs to environmental models.

High altitude aerial surveys have the potential to improve disturbance-free data collection in wildlife research, but previously, bird species were not recognizable in high-altitude orthophotos. This method of aerial surveying is effective and can be repeated frequently due to its low cost; it also has the additional advantage of being able to monitor the status of protected areas. In the case of waterbirds, due to the low vegetation coverage, aerial remote sensing is an exceptionally effective technique for surveying populations and detecting nests. Aerial surveys made at low altitudes can cause serious stress for birds. The method we developed and employed is unlikely to be detected by either ground-based or nesting birds but is far more reliable compared to the low-resolution imaging methods and to the evaluation of non-georeferenced photo series. The modern sensors and photogrammetric procedures enable the use of the present method worldwide; furthermore, the large-scale ortho image-derived information has become obtainable more frequently. Direct georeferencing makes the field geodetic survey unnecessary. Orthophotos with a 0.7 cm spatial resolution allow us to reliably identify even the individuals of smaller species, and by the use of oblique images, they can be tracked from two or four different directions.