Assessment of Land-sat Satellite Images used to calculate Land Surface Temperature(LST): A case study in Adhamiya Baghdad

With the help of this study, a method for extracting temperature of the land surface (LST) using data from thermal band 10 of LAND-SAT9 collection 1 levels -1 and collection 2 level 2 is described. This method uses satellite data from thermal infrared sensors (OLI & TIRS). This research aims to estimate the LST over the AL-Adhamiya area on the image date 02/20/2023 to retrieve and compare the (LST) including real-time measurements made while taking the images using an infrared thermometer camera, readings were made in direct contact with the object using ( K-type thermocouple ). The findings demonstrated that the LST varies depending on whether there is vegetation, bare soil, asphalt, or a residential area.=11 C°, 14-16 C°,13.9- 15.5 C° and 19.1 – 20.7 C° resprctivly. This study compares the association between different forms of land cover and (LST) and assesses how well land cover temperature amounts are described using LAND-SAT-9 data.

One of the most crucial factors in land-surface physical mechanisms at the regional and global levels is (LST) which incorporates Surface atmosphere interactions and all energy transfers amid the land and the atmosphere [1][2][3] [4].The surface energy balance, meteorology, and hydrology have all been extensively used [5].A crucial element of the climate system on Earth is (LST) [6] Remote sensing has a vital role in computing land surface temperature (LST) by a method for generating different LST products and measuring LST at both a regional and global level [7].A better knowledge of the landsurface-atmosphere interaction processes at both the global and regional scales may result from new LST insights, which may also offer a useful surface state indicator for a variety of subjects.Therefore (LST) has been known by the ( National Aeronautics and Space Administration), the United States Climate Change Science Program, and as a key parameter of the Earth's surface.New (LST) results may lead to better recognition of land surface-atmosphere interaction processes around the world, which may also offer a useful surface state indicator for a variety of applications.LST is recognized as an important land surface parameter by the Climate Observing System for the World, one of the ten primary climate variables in the terrestrial biosphere, according to the Program on Climate Change Science [8].The only means to quantify LST globally at a spatially averaged pixel size is by satellite observation, which uses broad-area coverage and frequent temporal revisiting [9].Since the 1960s, a variety of satellites, including several thermal infrared (TIR, 8-14 m ) wavelength region tools for the atmospheric window, have been aired on numerous satellite programs, including the National Administration satellite series Oceanic and Atmospheric (NOAA) satellites, the Land-sat Terra and Aqua series of Earth-observing system satellites.The second generation satellite series is a Meteosat (MSG), and the Chinese Fengyun satellite series (FY).LST stands for the thin layer's thermodynamic temperature, at the point where the soil, vegetation, or other surface elements meet the atmosphere.It depicts the temperature at which the Earth's surface would be at restrained touch.This thin layer, or ground surface, in remote sensing, is an unbroken projected surface.consisting of all immediately visible elements within the immediate area of view of the sensor (IFOV; Figure 1), its thickness is comparable 1300 (2024) 012006 IOP Publishing doi:10.1088/1755-1315/1300/1/012006 2 to the depth of penetration.The distance at which the radiation intensity starts to decline by 1/e (about 37%) is known as the penetration depth and may be stated as [10] Figure 1 Land surface mapping in remote sensing.
-Tsi, i, and ai stand for the visible component's surface temperature, emissivity, and anticipated area weight, respectively.-VZA stands for vertical zone angle, -v is the viewing azimuth angle.

̸ 4лK
Where: ⸹ₚ is the range of penetrating, ℷ₀ is the used for the measurement's wavelength, K is the refractive index portion between 0.01 and 1.The process of removing atmospheric factors and accounting for the Since after LST is derived read data, such as read temperature or brightness (BT), the effect of absorbance is also referred to as read temperature [11].The LST is distinct from other temperatures needed for a particular satellite sensor in several applications.For instance, radiometric temperature integration across the full spectrum and the upper hemisphere is frequently required for estimating surface radiant exitance [12].Additionally, for a reasonable heat flux, estimating the aerodynamic temperature is necessary [13], and raising the resistance when replacing such temperature with radiometric temperature is necessary to account for their discrepancies [14].

Literature review related to Land surface temperature
Earlier studies concentrated on modelling and monitoring the class regions to assess changes in LU/LC.As a result of these changes, there could be a loss of agricultural land, a reduction in water bodies, air pollution, and an increase in land surface temperature.As a result, RS and GIS could provide essential tools for the analysis.Several papers have been published in the area of interest.The most intriguing studies are those that we've chosen to highlight here: [15] proposed a way for the reclamation of land surface temperature (LST) from the LANDSAT-8 data's two thermal bands (10,11).Two images dated 2 and 18 March 2018 that used to derive the LST and compare it surface temperatures measured in the field with an simultaneously with the picture taking, an infrared thermometer camera was used.The correlation coefficient was 0.70 and 0.89 for bands 10 and 11 respectively for the image acquired on the 2 of March 2018 and 0.70 and 0.72 on the 18 th of March 2018 respectively.These results emphasize that the LANDSAT-8 Thermal bands are an effective way for LST retrieval.

Muhammad et al. (2018)
Salah A. (2010) [16] For the years 1961 to 2002, researchers looked into the use of remote sensing and geographic information systems (GIS) integration to detect built-up area expansion and assess its effects on surface temperature in Baghdad.The relationship between thermal conduct and the volume of green cover was investigated using the (NDVI).The conclusions of the regression and correlation studies of the surface temperature that were obtained from Landsat data images using the NDVI showed that a inverse correlation on average greater than 85% was detected.
Oday J. et al. ( 2020) [17] Using Landsat satellite photos and GIS technologies to map and analyze spatial variation for the thermal island, remote sensing is employed to identify the thermal island.(NDVI) is used to calculate vegetation cover between 2003 and 2018.The thermal band of satellite photos taken at the same period is used to determine the land surface temperature.While the NDVI values were high in 2003, ranging from (-0.714 to 0.693), indicating a high vegetative cover, they have significantly declined over the past 15 years, falling to (-0.22 to 0.509) in 2018.From 10.93 to 36.26 in 2003 to 22.62 to 50.29 in 2018, the land surface temperature (LST) has increased.All of this was accomplished at the cost of converting Baghdad's open green, and agricultural areas into areas used for business, housing, and industry, as well as the numerous haphazard settlements that began to spring up in the city after 2003.
S. Q. Al-Jbouri (2021) [18] In this governorate, the relationship between the normalized difference vegetation index (NDVI) and land surface temperature (LST) was investigated.Land surface temperature (LST) and the Normalized Difference Vegetation Index (NDVI) were employed in two of the Landsat-5 ETM + and Landsat-8 OLI satellite pictures obtained between 1999 and 2019.The findings showed that for 2019, NDVI climbed and LST declined, but for the three regions in 1999, LST increased and NDVI decreased.Finally, the association between LST and NDVI was discovered using regression.It was determined that there is a negative link between NDVI and LST, with 0.76 being the strongest correlation.
Salem M et al. ( 2023) [19] Land surface temperature (LST) estimation and monitoring of the majority of the Al-Anbar Governorate are supplied using Landsat imagery from five years (2005, 2010, 2015, 2016 and 2020).Landsat 5 (TM) captured the images from the years 2005 and 2010, whereas Landsat 8 (OLI/TIRS) captured the images from the remaining years.The Landsat 5 and Landsat 8 photos were used to obtain the LST using the Single Channel Algorithm.Moreover, the maximum likelihood The land use/land cover (LULC) maps for the five years were produced using a classifier.The observed discrepancy between the LST and normalized differential vegetation index (NDVI) readings during this period was caused by fluctuations in LULC.Finally, a regression analysis was done to model how the LST and NDVI relate to one another.The outcomes revealed Monserud et al., (1990) [20] Using data from Landsat 5 and 8 and TIRS, the LST in the Iraqi city of Najaf was examined between 1990 and 2017 with factors in LU/LC reflecting the city's growing urbanization.As a result, there was an increase in temperature in populated regions.The analysis of the data revealed both a large temperature increase and a minor expansion of the vegetation cover.With the decrease of sandy lands, where major changes were discovered in the research area, residential land might potentially rise dramatically.Beg, et al., (2018) [21] In arid regions, temperatures ranged from 26°C to 41°C, whereas in vegetation areas, they ranged from 25°C to 35°C.While the amounts of vegetative cover and bare land decreased from 16% to 6% in the study region, there was an inverse link between LST and NDVI.This study examined how the increase in population in Baghdad, Iraq, hurts services and the summertime temperature.

Study area
The historical centre of this study is the Al-Adhamiya neighbourhood, which is crucial for the research since it has all the qualities that set it apart from other historical hubs in Baghdad, as shown in Fig. 1.It was limited by latitude 30• 20' 00" N to 33• 30' 00" N and longitude 44• 20' 00" E to 44• 20'00" E.  In order to determine whether the temperature obtained from Landsat-9 satellite imagery and a manually operated ground device for measuring object temperatures and using the results in the creation of maps that classify the Earth based on temperature are compatible, and measurements were made of the temperatures of several types of land cover items in the research area.These temperatures were then compared with the temperature obtained from Landsat-9 satellite imagery, This was obtained in 2023 and comprised ten photos shot in three different seasons of the year.Satellite data over Al-Adhamiya city on the 20 of February 2023 (daytime, path 168/raw 38, level-1TP product) were employed in this investigation.were downloaded with a 9-point image quality from the USGS.The research area includes a residential neighbourhood, bare ground, and vegetation.The data were all reprojected to a datum WGS84, zone 38, Universal Transverse Mercator coordinate system (UTM).

Infrared Thermometer Camera (IR Thermometer)
Temperature is measured with an infrared thermometer. of an impermeable object's surface [22].The energy that is transmitted, reflected, and sensed by the The optics of a thermometer are gathered and directed toward a detector.The electronics of the device convert the data a temperature reading is converted and shown on the screen.(see Figure 1).An infrared thermometer camera, shown in Figure 1, is used to measure temperature without contact.The magnitude of infrared radiation sent out by an object's surface can be measured, this thermometer can determine its surface temperature [22].As seen in Figure (1-b), the thermometer supports measuring contact temperature using a K-type thermocouple.In this study, type-K (thermocouple) thermometers were used for all ground-truth observations of land surface temperature.Table 2 illustrates the features of the IR temperature camera.

The accuracy of Land Surface Temperature (LST) computation using Land-sat Collection 1 and Land-sat Collection 2 data:
The accuracy of Land Surface Temperature (LST) computation using Land-sat Collection 1 and Land-sat Collection 2 data can vary depending on several factors, including the specific Land-sat satellite, the quality of the data, and the methods employed.Here is an overview of both collections:

Material and Methods: 3.1 Land Surface Temperature (LST) Computation using Land-sat Collection 1 Data :
The Land-Sat 9 satellite pictures are the data used in this investigation acquired in February 2023, Data used are "Band 10 for the thermal infrared (OLI) sensor (10.6 -11.19 µm) at 100m resolution, 'Band 4 red (0.64 -0.67 µm) 30m' and 'Band 5 for near infrared (0.85 -0.88 µm) ) 30 meters from Land-sat9 Operational Land Imager (OLI).LST is calculated by a series of applied band-based mathematical algorithms.Bands 4 and 5 are applied to compute the NDVI index, and Band 10 OLI is used to estimate brightness.Using the metadata file, the thermal infrared bands should be convert to brightness temperature (BT) [2]: Where: The information file associated with the satellite image contains (TIRS) bands 10 K1 and K2.
To have the results in Celsius (C•), Refinement requires the addition of absolute zero, roughly equivalent to (273.15).
Where: NIR stands for the pixel's near-infrared band intensity, RED for its red band.Note: Calculating proportional vegetation (Pv) and emissivity (e) both depend on the NDVI.Note: NDVI of the pure pixel is used to determine the proportions of plant and bare soil.To estimate LST, one must calculate the "land surface emissivity" (LSE).This term refers to a surface's capability to absorb longwave radiation.The kind of soil, the roughness of the surface, and the type of green cover all play a role in LSE.The subsequent equation utilizing LSE will provide [5]: The last step is to determine LST using LSE, which is calculated from Pv and NDVI, and the brightness temperature (BT) of band 10 and LSE.The following equation can be used to retrieve LST [6]: Where

Validation and Results : 4.1 Validation of LST:
Land-sat-9 collection 1level 1 and collection 2 level 2 data of 20, February 2023 have been retrieved (LST) and was evaluated.derived LST from satellite information was confirmed by field observation from the research region at the same time as the satellite overflight, which, by local standard time was (7:34:22 AM) for collection 1level 1, (07:33:58 AM) for collection 2level 2 according to Metadata.With the use of a handhold, in-situ observation was conducted manually.IR camera for measuring temperature (IR thermometer) at numerous observation locations across the various land cover types present in the study area.A temperature contrast ratio has been discovered between the obtained band 10. Results of LST and in-situ temperature observations for nine sites, ranging from (9.9 -26.2 C•) for collection1 level 1 and (2.3 -48.2) for collection 2level 2 as shown in the table above.The relationship between temperatures recorded by a field IR-thermometer camera and LST calculated from LAND-SAT recorded a few differences ranging between (-0.89-2.45)for collection 1level 1 and (2.84 -8.65) for collection 2level 2. This is an excellent example of how temperatures generated from satellites are relied upon in vast regions, where doing so requires more time and money than using satellites and necessitates.

Results :
The absence of measurements was performed within an hour as opposed to the scene centre time recorded of the photos being acquired, which was at contributed to the good results reported (7:34:22 AM) for collection1level 1, (07:33:58 AM) for collection 2level 2 local time.As a result, for different land covers, the calculated LST and IR-thermometer data showed a lower and bigger temperature difference depending on the period between land cover temperature measurements made in the field during image acquisition.Reducing the cost, effort, and time required to produce data with an adequate resolution is one benefit of adopting remote sensing techniques for land surface temperature modelling.

Conclusion 1-
The proposed algorithm was formed using the (BT) of bands 10 and (E) of various land cover types, derived from LAND-SAT-9 bands 4 and 5. Using an infrared thermometer camera in direct contact with the ground, the estimated LSTs were confirmed.By examining the tables above and contrasting the two photos' measurement findings (Collection 1 -Level 1 and Collection 2 -Level 2), the results show the first image (Collection 1 -Level 1 ) was given a high correlation coefficient of bands 10 = 0.8055,while second image (Collection 2 -Level 2 ) a gave low correlation coefficient of bands 10 = 0.495.2-The vegetation effect negatively on land surface temperature more than the other areas.3-There is a greater impact of the built-up area than the bare land area on land surface temperature, and there is a positive association between the two.4-The link between the indicators of land cover and the land surface temperatures collected from Land-sat satellites suggested the prospect of monitoring several Earth surface events including desertification, urban development and expansion, drought, and wetlands.

Figure 2 .
Figure 2. Location of the study area 2.1 Data Set The USGS website was used to gather multispectral remote sensing technique photos of Al Adhamiya city with the dates (20-2-2023).Every 16 days, LAND-SAT-9 satellite imagery returns to Earth.Table 1 lists the LAND-SAT-9 band descriptions.
The infrared thermometer was used to record field measurements.At the time as the photos were being acquired, observations were measured near the land surface.For February 20 and 21, 2023, the minimum and maximum temperature ranges were 11.4 to 20.7 C. The field measurements and their timetables are listed below (3).

13 Figure 10 .
Figure 10.Land Surface Emissivity (LSE) map (Feb.2023) 6.The last step is to determine LST using LSE, which is calculated from Pv and NDVI, and the brightness temperature (BT) of band 10 and LSE.The following equation can be used to retrieve LST[6]:

Table 1 .
Table 1 lists the LAND-SAT-9 band descriptions.Characteristics of Land-sat-9 bands