Geomatics for Urban Analysis 2024/2025 PDF

GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) G. Bitelli Some definitions of Remote Sensing Geomatics for Urban and Regional Analysis G. Bitelli...

GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) G. Bitelli Some definitions of Remote Sensing Geomatics for Urban and Regional Analysis G. Bitelli Remote sensing can be defined as the set of techniques, tools and interpretative means that allow you to extend and improve the perceptive capabilities of the human eye, providing the observer with qualitative and quantitative information on objects placed at a distance and in the Introduction to Remote Sensing surrounding environment. Remote sensing is the set of instrumentation, techniques and methods to acquire, process and interpret images that record the interaction between electromagnetic energy and the Earth. Note: there is a medium of transmission involved, the Earth’s Atmosphere. Remote sensing is the science or art of obtaining information about an object, area, or phenomenon by analyzing data acquired by means of a device that is not in contact with the object, area or phenomenon under examination. The processes of collecting information about Earth surfaces and phenomena using sensors not in physical contact with the surfaces and phenomena of interest. The current situation of Earth Observation The Remote Sensing process (EO) for civil purposes: growing number of systems and spatial missions, by governmental or supranational agencies or by private companies / consortia scientific or commercial purposes Very High Resolution (VHR) imagery (now up to 30-40 cm in panchromatic) short revisit time hyperspectrality … VHR started in 1999 with IKONOS (1 m in PAN) Ikonos (first VHR sensor), 11 september 2001 Landsat missions (NASA, USGS) European Space Agency: the Sentinel missions Landsat 9 launch (September 27, 2021) GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) 1 G. Bitelli  GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) G. Bitelli The electromagnetic spectrum The electromagnetic energy emitted by the Sun The electromagnetic spectrum: visible Scientific discoveries: ultraviolet and infrared… UV IR Remote sensing systems for Earth Observation The data acquired along the orbit is converted into a digital form... Passive Vs Active Sensors emitted … and sent to the receiving stations on Earth GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) 2 G. Bitelli  GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) G. Bitelli Passive sensor Multi-band (multispectral) digital images Multi-band (multispectral) digital images The 4 concepts of resolution in Remote Sensing Geometric Radiometric Resolution Spectral Temporal Example (7 bands) Spatial (=geometrical) resolution The earth surface area covered by a pixel of an image Large area covered by a pixel means low spatial resolution and vice versa GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) 3 G. Bitelli  GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) G. Bitelli Spectral resolution It is related to the number and width of the bands on which the sensor operates: high spectral resolution many narrow windows in the e.m. spectrum Multispectral, Hyperspectral Multispectral Hyperspectral Multispectral imagery For a generic pixel: (Landsat 7 mission) GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) 4 G. Bitelli  GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) G. Bitelli An example of a commercial multispectral sensor (World-View 3) Radiometric resolution and related applications Sensitivity of the sensor to the magnitude of the received electromagnetic energy determines the radiometric resolution Finer the radiometric resolution of a sensor, if it is more sensitive in detecting small differences in reflected or emitted energy 00000000 00 - 01 - 10 – 11 00000001 → values 0÷3 …. 11111111 → values 0÷255 Radiometric resolution Ikonos images showing the impact of improving radiometric resolution. In the upper part of the figure, different roofs can only be discriminated when enough radiometric resolution is available, while in the lower part, the same applies to the darker areas Number of bits dynamic range DN 11 bits: 2048 8 bits: 256 8 the most common 0-255 10 0-1023 11 0-2047 Bright areas 12 recent sensors 0-4095 16 0-65535 A higher radiometric resolution leads to better performance in the discrimination of small differences Dark areas in the mapped phenomena (e.g. ocean temperatures) and also greater readability of the image (e.g. in the visible for shaded areas) (Courtesy Indra Espacio). Temporal resolution Temporal resolution Frequency at which images are recorded/captured in a specific place on the Earth. The more frequently it is captured, the better or finer the temporal resolution is said to be (e.g. useful for disaster monitoring) A sensor that captures an image of a land twice a day has better temporal resolution than a sensor that only captures that same image once a week. July 2 July 18 August 3 16 days Revisit intervals and equatorial crossing times for several satellite remote sensing systems. The specifications assume only one system in operation, with the exception of the AVHRR, which normally operates in pairs, and the two MODIS systems, Time allowing morning and afternoon viewing of the same area in one day. The GOES is 11 days in a geostationary orbit and is always pointed at the same area of the earth. Equatorial crossing times are only approximate, as they change continually by small July 1 July 12 July 23 August 3 amounts and orbit adjustments are needed periodically. GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) 5 G. Bitelli  GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) G. Bitelli Temporal resolution and monitoring of the territory Average reflectance curves and spectral behavior of three typical cover types soil reflectance Vegetation vegetation Water Soil water wavelenght VIS NIR SWIR GREEN NEAR MEDIUM INFRARED BLUE RED INFRARED (see part 3) A multispectral image: different contents for the different bands (Landsat TM 5) Band 1 Band 2 Band 3 GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) 6 G. Bitelli  GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) G. Bitelli Band 4 Band 5 Band 7 Band 6 3 different ways to represent the data Feature space (k dimensions) Nord K=2 K=3 K = 7 bands Est Object space DN band j geographic location for each individual pixel Spectral space physical behavior of the pixel: reflectance as a function of wavelength in DN band i the captured k bands Feature space (n-dimensional scatterogram, here n=2): each point refers to a pixel in the image GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) 7 G. Bitelli  GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) G. Bitelli Urban & Regional Planning Agriculture Scope Scope Mapping & updation of Lyari Express Way – Section (Essa Nagri) Crop acreage estimation city/town maps Crop modeling for yield & Urban sprawl monitoring production forecast / estimation Town planning Crop & Orchard monitoring Facility management GIS database development Benefits Timely availability of crop Benefits statistics for decision making & FFC Goth Macchi Better decision support, planning Dec 16, 2005, Pre-Frost Jan 12, 2006, Damage Mar 05, 2006, Recovery planning & management Crop growth monitoring Rapid information updation Soil status monitoring Infrastructure development Regular reports regarding total monitoring area under cultivation Spatial information analysis Banana Plantation – Muhammad Pur (Ghotki) Flood Damage to Standing Crops Forestry Scope Pre Flood – 17 July 2006 Post Flood – 09 Aug 2006 Satellite image based forest resource mapping and updation Muhro Mari Muhro Mari Forest change detection Darapur Darapur Kot Shahgarch Kot Shahgarch Forest resource inventory 10098 acr GIS database development Godhpur Godhpur Phulani Phulani Than Lake Benefits Sarhad Reserve Forest (Ghotki) Than Lake Goth Lataran Goth Lataran Availability of baseline Shahpur Shahpur Ural Ural information Junno Dhand Junno Dhand Planning for aforestation Goth Raza Mahar Goth Raza Mahar strategies Goth Azizpur Goth Azizpur Futuristic resource planning Sustainability of environment 3516 acr Wild life conservation & development for recreation purpose Sukkur Nausharo Firoz Coastal Resource Mapping Landuse / Landcover Mapping Scope Mangrove forest monitoring Scope Change detection Monitoring dynamic changes Hazard impacts Urban/Rural infrastructure Aqua-culture zones Waterlogging & salinity Benefits Benefits Availability of updated Assessment of spatial distribution information on mangroves of land resources forest Infrastructure monitoring Planning strategies for Availability of usable land aforestation and deforestation Future planning for better land trend management for socio-economic Timely Intervention in specific development areas as and when needed Satellite image Mangroves forest map GEOMATICS FOR URBAN AND REGIONAL ANALYSIS (2024/2025) 8 G. 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