Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Más filtros











Intervalo de año de publicación
1.
Braz. j. biol ; 84: e260615, 2024. tab, ilus, mapas
Artículo en Inglés | VETINDEX | ID: biblio-1374660

RESUMEN

This article describes the environmental impacts of producing a single seedling in forest nurseries of selected districts (i.e., Haripur, Abbottabad, and Mansehra) of Hazara Division of Khyber Pakhtunkhwa, Pakistan using the life cycle assessment (LCA) approach. This study was based on the cradle-to-gate approach which begins with the pre-nursery stage and progresses toward the main nursery before transplanting seedlings into the plantation site. Data or life cycle inventory (LCI) of seedling production were collected through questionnaire surveys and personal meetings with forest nurseries managers and workers regarding consumption of different inputs such as electricity, diesel, fertilizers, herbicides, and polyethylene bags, organic manure, and water consumption. The SimaPro software version 8.5 and the CML2000 v2.05 environmental model was applied to perform life cycle impact assessment (LCIA) for a single seedling production in forest nurseries in the study area. In line with the objectives of the study, primary data regarding inputs and outputs of the nurseries were collected from 35 nurseries in the study area by using a random questionnaire method. In addition, secondary data were taken from online databases such as Eco-invent v.3.2 CORRIM and peer-reviewed published literature. For this study, a functional unit of a single seedling was considered. Production weighted average data were modeled in the latest environmental modeling software i.e., SimaPro v.8.5 for ten US-EPA most wanted environmental impacts, such as global warming potential (GWP), abiotic depletion (AD), eutrophication potential (EP), acidification potential (AP), freshwater aquatic eco-toxicity (FAE), marine water eco-toxicity (MWE), terrestrial eco-toxicity (TE), ozone layer depletion (OLD), photochemical oxidation (PO), and human toxicity (HT). The results showed that the highest environmental impact posed by a single seedling was marine aquatic eco-toxicity (11.31360 kg 1,4-DB eq), followed by global warming potential (0.02945 kg CO2 eq) and (0.01227 kg 1,4-DB eq) human toxicity. The primary reason for these environmental burdens was the use of synthetic fertilizers in forest nurseries and the consumption of fossil fuels in nursery mechanization and transportation activities. The total cumulative energy demand for a single seedling was (0.800 MJ) with more than 90% contribution from fossil fuel energy resources such as petrol and diesel. It is therefore highly recommended to use renewable energy resources and organic fertilizers instead of chemical fertilizers in forest nurseries to avoid and minimize greenhouse gas emissions (GHS) and other toxic emissions in the study area.


Este artigo descreve os impactos ambientais da produção de uma única muda em viveiros florestais de distritos selecionados (Haripur, Abbottabad e Manshera) da divisão Hazara, de Khyber Pakhtunkhwa, Paquistão, usando a abordagem de avaliação do ciclo de vida (ACV). Este estudo baseou-se na abordagem "do berço ao portão", que se inicia na fase pré-viveiro e progride em direção ao viveiro principal antes do transplante das mudas para o local de plantio. Os dados ou inventário de ciclo de vida (ICV) da produção de mudas foram coletados por meio de questionários e reuniões pessoais com o gerente e os trabalhadores dos viveiros florestais sobre o consumo de diferentes insumos, como energia elétrica, diesel, fertilizantes, herbicidas, sacos de polietileno, adubo orgânico e consumo de água. O software SimaPro, versão 8.5, e o modelo ambiental CML2000, v2.05, foram aplicados para realizar a avaliação de impacto do ciclo de vida (AICV) de uma única produção de mudas em viveiros florestais na área de estudo. Em consonância com os objetivos do estudo, os dados primários relativos às entradas e saídas dos viveiros foram coletados de 35 viveiros na área de estudo por meio de um método de questionário aleatório. Além disso, dados secundários foram obtidos de bancos de dados online, como Eco-invent v.3.2 CORRIM e literatura publicada revisada por pares. Para este estudo, foi considerada uma unidade funcional de uma única plântula. Os dados médios ponderados de produção foram modelados no software de modelagem ambiental mais recente, ou seja, SimaPro, v.8.5, para 10 impactos ambientais mais desejados pela US-EPA, como potencial de aquecimento global (PAG), depleção abiótica (DA), potencial de eutrofização (PE), potencial de acidificação (PA), ecotoxicidade de água doce (EAD), ecotoxicidade da água marinha (EAM), ecotoxicidade terrestre (ET), destruição da camada de ozônio (DCO), oxidação fotoquímica (OF) e toxicidade humana (TH). Os resultados mostraram que o maior impacto ambiental causado por uma única muda foi a ecotoxicidade da água marinha (11,31360 kg 1,4-DB eq), seguido pelo potencial de aquecimento global (0,02945 kg CO2 eq) e toxicidade humana (0,01227 kg 1,4-DB eq) eq). A principal razão para esses ônus ambientais foi o uso de fertilizantes sintéticos em viveiros florestais e o consumo de combustíveis fósseis nas atividades de mecanização e transporte de viveiros. A demanda total acumulada de energia para uma única muda foi de 0,800 MJ, com mais de 90% de contribuição de recursos energéticos de combustíveis fósseis, como gasolina e diesel. Portanto, é altamente recomendável usar recursos de energia renovável e fertilizantes orgânicos em vez de fertilizantes químicos em viveiros florestais para evitar e minimizar as emissões de gases de efeito estufa (GEE) e outras emissões tóxicas na área de estudo.


Asunto(s)
Madera , Agricultura Forestal/métodos , Indicadores de Desarrollo Sostenible , Pakistán
2.
Braz. j. biol ; 84: e262662, 2024. tab, ilus, mapas
Artículo en Inglés | VETINDEX | ID: biblio-1384097

RESUMEN

A socio-economic study was conducted in district Mardan of the Khyber Pakhtunkhwa (KP) province of Pakistan to get a comprehensive knowledge of the agroforestry tree species grown on the farmlands, their yield, and carbon stock. For yield and carbon stock estimation, data were collected from 59 sample plots by measuring the diameter, height, volume, and biomass of selected agroforestry tree species through D-tape and Haga altimeter. A total of 59 sample plots were inventoried using 2.5 percent sampling intensity. Each sample plot has an area of 0.5 ha, where each tree with a Diameter at Breast Height (DBH) ≥ 5 cm was inventoried. The calculated amount of volume of each tree species was then converted to biomass by multiplying it by the density of wood and the Biomass Expansion Factor (BEF). Total yield and C stock for the selected agroforestry tree species were 11535.2 metric tons and 2102.2 metric tons, respectively. Populus euroamericana is classified as the main tree with 28% growing stock prior to Morus alba by 21%, while Melia azedarach, Eucalyptus camaldulensis, Dalbergia sissoo, Acacia nilotica, Salix tetrasperma, and Bombax ceiba consist of 15%, 12%, 8%, 6%,7% and 3% growing stock respectively. Among the species found in different sampling plots the yield of Populus euroamericana was found to be 4747.5 metric tons and it was followed by the species Morus alba found at 2027.3 metric tons. Similarly, the volume for Melia azedarach, Eucalyptus camaldulensis, Dalbergia sissoo, Salix spp, Boombox ceiba, and Acacia nilotica was 1532.2 tons,1503 ton,745.7,203.5ton, 555.4ton and 220.5ton, respectively. The carbon stock for Populus euroamericana was calculated as 777.8 ton/ha, while for Eucalyptus camaldulensis, Melia azedarach, Morus alba, Dalbergia sissoo, Acacia nilotica, Salix species, and Bombax ceiba it was calculated as 312.3ton/ha, 272.1ton/ha, 363ton/ha, 245.1ton/ha, 51.4ton/ha, 27.3ton/ha and 53.2ton/ha, respectively. The questionnaire survey conducted for price dynamics showed that the majority of respondents purchase timber from the market for construction. But they use farm trees with low-quality city construction. They dislike using local timber in the conventional building as timber from farm trees is liable to insect attack. Rs. 50,000-100000, (33.33%) of daily sales was concluded from 50% of the trader while (16.7%) of the traders have their sales between Rs.150,000-200,000. Therefore, it is concluded by the authors that both provincial and federal government should promote agroforestry in Pakistan through different incentives because it has the potential to cope with dilemma of deforestation of natural forests and improve the livelihood of local peoples. It is strongly recommended that special projects just like the Ten Billion Tree Afforestation Project (T-BTTP) should be launched for agroforestry plantation and promotion in the country to sustain the ecological harmony and uplift the socio-economic condition of the peoples of Pakistan.


Um estudo socioeconômico foi realizado no distrito de Mardan, da província de Khyber Pakhtunkhwa (KP), Paquistão, para obter maior conhecimento das espécies de árvores agroflorestais cultivadas em terras agrícolas, seu rendimento e estoque de carbono. Para a estimativa de produção e estoque de carbono, foram coletados os dados de 59 parcelas amostrais, medindo-se o diâmetro, a altura, o volume e a biomassa de espécies de árvores agroflorestais selecionadas por meio de fita D e altímetro Haga. Um total de 59 parcelas amostrais foi inventariado usando 2,5% de intensidade de amostragem. Cada parcela amostral possui uma área de 0,5 ha, em que cada árvore com Diâmetro à Altura do Peito (DAP) ≥ 5 cm foi inventariada. A quantidade calculada de volume de cada espécie de árvore foi então convertida em biomassa, multiplicando-a pela densidade da madeira e pelo Fator de Expansão da Biomassa (BEF). A produção total e o estoque de C para as espécies de árvores agroflorestais selecionadas foram 11.535,2 toneladas métricas e 2.102,2 toneladas métricas, respectivamente. Populus euroamericana foi classificada como a principal árvore com 28% de crescimento de estoque, seguida de Morus alba com 21%, enquanto Melia azedarach, Eucalyptus camaldulensis, Dalbergia sissoo, Acacia nilotica, Salix tetrasperma e Bombax ceiba apresentaram 15%, 12%, 8%, 6%, 7% e 3% de crescimento do estoque, respectivamente. Entre as espécies encontradas em diferentes parcelas de amostragem, o rendimento de Populus euroamericana foi de 4.747,5 toneladas, seguida pela espécie Morus alba, com rendimento de 2.027,3 toneladas. Da mesma forma, o volume de Melia azedarach, Eucalyptus camaldulensis, Dalbergia sissoo, Salix spp, Bombax ceiba e Acacia nilotica foi de 1.532,2 toneladas, 1.503 toneladas, 745,7 toneladas, 555,4 toneladas e 220,5 toneladas, respectivamente. O estoque de carbono para Populus euroamericana foi calculado como 777,8 ton/ha, enquanto para Eucalyptus camaldulensis, Melia azedarach, Morus alba, Dalbergia sissoo, Acacia nilotica, Salix species e Bombax ceiba foi calculado como 312,3 ton/ha, 272,1 ton/ha, 363 ton/ha, 245,1 ton/ha, 51,4 ton/ha, 27,3 ton/ha e 53,2 ton/ha, respectivamente. A pesquisa por questionário, realizada para a dinâmica de preços, mostrou que os entrevistados, em sua maioria, compram madeira do mercado para construção, mas usam árvores de fazenda em construções urbanas de baixa qualidade. Eles não gostam de utilizar a madeira local na construção convencional, pois ela é suscetível ao ataque de insetos. Em relação às vendas diárias, 50% dos comerciantes vendem entre Rs. 50.000-100.000, enquanto 16,7% têm suas vendas entre Rs.150.000-200.000. Portanto, conclui-se que tanto o governo provincial quanto o governo federal devem promover, por meio de diferentes incentivos, a agrossilvicultura no Paquistão, por ter o potencial de lidar com o dilema do desmatamento de florestas naturais e melhorar a subsistência das populações locais. É fortemente recomendado que projetos especiais, como o Projeto de Reflorestamento de Dez Bilhões de Árvores (T-BTTP), sejam lançados para plantio agroflorestal e promoção no país para sustentar a harmonia ecológica e elevar a condição socioeconômica dos povos do Paquistão.


Asunto(s)
Árboles , Carbono , Comercio , Pakistán
3.
Braz J Biol ; 82: e267584, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36449831

RESUMEN

Plant leaves and roots are home to diverse communities of bacteria, which play a significant role in plant health and growth. Although one of the most unfriendly environments for plant growth is deserts, desert plants can influence their surrounding microbial population and choose favorable bacteria that encourage their growth under these severe circumstances. Senna italica is known for its excellent medicinal values as a traditional medical plant, but little is known about its associated endophytic bacterial community under extreme conditions. In the present study, metagenomic sequencing of 16S rRNA was used to report the diversity of endophytic bacterial communities associated with the leaves and roots of the desert medicinal plant Senna italica that was collected from the Asfan region in northeast Jeddah, Saudi Arabia. Analyses of the 16S rRNA sequences at the taxonomic phylum level revealed that bacterial communities in the roots and leaves samples belonged to five phyla, including Cyanobacteria, Proteobacteria, Actinobacteria, Firmicutes, and unclassified phyla. Results indicated that the most common phyla were Cyanobacteria/Chloroplast and Actinobacteria. Analysis of the 16S rRNA sequences at the taxonomic phylum level revealed that bacterial communities in the roots and leaves samples belonged to twelve genera at the taxonomic genus level. The most abundant ones were highlighted for further analysis, including Okibacterium and Streptomyces found in Actinobacteria, which were the dominant genus in roots samples. However, Streptophyta found in Cyanobacteria/Chloroplast was the dominant genus in leaf samples. Metagenomic analysis of medicinal plants leads to identifying novel organisms or genes that may have a role in abiotic stress resistance in the plant. The study of endophytic microbiome taxonomic, phylogenetic, and functional diversity will better know innovative candidates that may be selected as biological agents to enhance agricultural and industrial processes, especially for crop desert agricultural improvement.


Asunto(s)
Bacterias , Endófitos , Endófitos/genética , ARN Ribosómico 16S/genética , Filogenia , Bacterias/genética , Estrés Fisiológico
4.
Braz J Biol ; 84: e262662, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35830134

RESUMEN

A socio-economic study was conducted in district Mardan of the Khyber Pakhtunkhwa (KP) province of Pakistan to get a comprehensive knowledge of the agroforestry tree species grown on the farmlands, their yield, and carbon stock. For yield and carbon stock estimation, data were collected from 59 sample plots by measuring the diameter, height, volume, and biomass of selected agroforestry tree species through D-tape and Haga altimeter. A total of 59 sample plots were inventoried using 2.5 percent sampling intensity. Each sample plot has an area of 0.5 ha, where each tree with a Diameter at Breast Height (DBH) ≥ 5 cm was inventoried. The calculated amount of volume of each tree species was then converted to biomass by multiplying it by the density of wood and the Biomass Expansion Factor (BEF). Total yield and C stock for the selected agroforestry tree species were 11535.2 metric tons and 2102.2 metric tons, respectively. Populus euroamericana is classified as the main tree with 28% growing stock prior to Morus alba by 21%, while Melia azedarach, Eucalyptus camaldulensis, Dalbergia sissoo, Acacia nilotica, Salix tetrasperma, and Bombax ceiba consist of 15%, 12%, 8%, 6%,7% and 3% growing stock respectively. Among the species found in different sampling plots the yield of Populus euroamericana was found to be 4747.5 metric tons and it was followed by the species Morus alba found at 2027.3 metric tons. Similarly, the volume for Melia azedarach, Eucalyptus camaldulensis, Dalbergia sissoo, Salix spp, Boombox ceiba, and Acacia nilotica was 1532.2 tons,1503 ton,745.7,203.5ton, 555.4ton and 220.5ton, respectively. The carbon stock for Populus euroamericana was calculated as 777.8 ton/ha, while for Eucalyptus camaldulensis, Melia azedarach, Morus alba, Dalbergia sissoo, Acacia nilotica, Salix species, and Bombax ceiba it was calculated as 312.3ton/ha, 272.1ton/ha, 363ton/ha, 245.1ton/ha, 51.4ton/ha, 27.3ton/ha and 53.2ton/ha, respectively. The questionnaire survey conducted for price dynamics showed that the majority of respondents purchase timber from the market for construction. But they use farm trees with low-quality city construction. They dislike using local timber in the conventional building as timber from farm trees is liable to insect attack. Rs. 50,000-100000, (33.33%) of daily sales was concluded from 50% of the trader while (16.7%) of the traders have their sales between Rs.150,000-200,000. Therefore, it is concluded by the authors that both provincial and federal government should promote agroforestry in Pakistan through different incentives because it has the potential to cope with dilemma of deforestation of natural forests and improve the livelihood of local peoples. It is strongly recommended that special projects just like the Ten Billion Tree Afforestation Project (T-BTTP) should be launched for agroforestry plantation and promotion in the country to sustain the ecological harmony and uplift the socio-economic condition of the peoples of Pakistan.


Asunto(s)
Eucalyptus , Árboles , Biomasa , Carbono/análisis , Bosques , Pakistán
5.
Braz J Biol ; 84: e260615, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35544796

RESUMEN

This article describes the environmental impacts of producing a single seedling in forest nurseries of selected districts (i.e., Haripur, Abbottabad, and Mansehra) of Hazara Division of Khyber Pakhtunkhwa, Pakistan using the life cycle assessment (LCA) approach. This study was based on the cradle-to-gate approach which begins with the pre-nursery stage and progresses toward the main nursery before transplanting seedlings into the plantation site. Data or life cycle inventory (LCI) of seedling production were collected through questionnaire surveys and personal meetings with forest nurseries managers and workers regarding consumption of different inputs such as electricity, diesel, fertilizers, herbicides, and polyethylene bags, organic manure, and water consumption. The SimaPro software version 8.5 and the CML2000 v2.05 environmental model was applied to perform life cycle impact assessment (LCIA) for a single seedling production in forest nurseries in the study area. In line with the objectives of the study, primary data regarding inputs and outputs of the nurseries were collected from 35 nurseries in the study area by using a random questionnaire method. In addition, secondary data were taken from online databases such as Eco-invent v.3.2 CORRIM and peer-reviewed published literature. For this study, a functional unit of a single seedling was considered. Production weighted average data were modeled in the latest environmental modeling software i.e., SimaPro v.8.5 for ten US-EPA most wanted environmental impacts, such as global warming potential (GWP), abiotic depletion (AD), eutrophication potential (EP), acidification potential (AP), freshwater aquatic eco-toxicity (FAE), marine water eco-toxicity (MWE), terrestrial eco-toxicity (TE), ozone layer depletion (OLD), photochemical oxidation (PO), and human toxicity (HT). The results showed that the highest environmental impact posed by a single seedling was marine aquatic eco-toxicity (11.31360 kg 1,4-DB eq), followed by global warming potential (0.02945 kg CO2 eq) and (0.01227 kg 1,4-DB eq) human toxicity. The primary reason for these environmental burdens was the use of synthetic fertilizers in forest nurseries and the consumption of fossil fuels in nursery mechanization and transportation activities. The total cumulative energy demand for a single seedling was (0.800 MJ) with more than 90% contribution from fossil fuel energy resources such as petrol and diesel. It is therefore highly recommended to use renewable energy resources and organic fertilizers instead of chemical fertilizers in forest nurseries to avoid and minimize greenhouse gas emissions (GHS) and other toxic emissions in the study area.


Asunto(s)
Fertilizantes , Plantones , Bosques , Combustibles Fósiles , Humanos , Pakistán
6.
Braz. j. biol ; 82: e267584, 2022. tab, ilus
Artículo en Inglés | VETINDEX | ID: biblio-1403819

RESUMEN

Plant leaves and roots are home to diverse communities of bacteria, which play a significant role in plant health and growth. Although one of the most unfriendly environments for plant growth is deserts, desert plants can influence their surrounding microbial population and choose favorable bacteria that encourage their growth under these severe circumstances. Senna italica is known for its excellent medicinal values as a traditional medical plant, but little is known about its associated endophytic bacterial community under extreme conditions. In the present study, metagenomic sequencing of 16S rRNA was used to report the diversity of endophytic bacterial communities associated with the leaves and roots of the desert medicinal plant Senna italica that was collected from the Asfan region in northeast Jeddah, Saudi Arabia. Analyses of the 16S rRNA sequences at the taxonomic phylum level revealed that bacterial communities in the roots and leaves samples belonged to five phyla, including Cyanobacteria, Proteobacteria, Actinobacteria, Firmicutes, and unclassified phyla. Results indicated that the most common phyla were Cyanobacteria/Chloroplast and Actinobacteria. Analysis of the 16S rRNA sequences at the taxonomic phylum level revealed that bacterial communities in the roots and leaves samples belonged to twelve genera at the taxonomic genus level. The most abundant ones were highlighted for further analysis, including Okibacterium and Streptomyces found in Actinobacteria, which were the dominant genus in roots samples. However, Streptophyta found in Cyanobacteria/Chloroplast was the dominant genus in leaf samples. Metagenomic analysis of medicinal plants leads to identifying novel organisms or genes that may have a role in abiotic stress resistance in the plant. The study of endophytic microbiome taxonomic, phylogenetic, and functional diversity will better know innovative candidates that may be selected as biological agents to enhance agricultural and industrial processes, especially for crop desert agricultural improvement.


As folhas e raízes das plantas abrigam diversas comunidades de bactérias, que desempenham um papel significativo na saúde e no crescimento das plantas. Embora um dos ambientes mais hostis para o crescimento de plantas sejam os desertos, as plantas do deserto podem influenciar a população microbiana circundante e escolher bactérias favoráveis ​​que encorajem seu crescimento sob essas circunstâncias severas. Senna italica é conhecida por seus excelentes valores medicinais como planta medicinal tradicional, mas pouco se sabe sobre sua comunidade bacteriana endofítica associada em condições extremas. No presente estudo, o sequenciamento metagenômico de 16S rRNA foi usado para relatar a diversidade de comunidades bacterianas endofíticas associadas às folhas e raízes da planta medicinal do deserto Senna italica que foi coletada na região de Asfan no nordeste de Jeddah, Arábia Saudita. Análises das sequências de rRNA 16S no nível taxonômico do filo revelaram que as comunidades bacterianas nas amostras de raízes e folhas pertenciam a cinco filos, incluindo Cyanobacteria, Proteobacteria, Actinobacteria, Firmicutes e filos não classificados. Os resultados indicaram que os filos mais comuns foram Cyanobacteria/Cloroplast e Actinobacteria. A análise das sequências de rRNA 16S no nível taxonômico do filo revelou que as comunidades bacterianas nas amostras de raízes e folhas pertenciam a doze gêneros no nível taxonômico de gênero. Os mais abundantes foram destacados para análise posterior, incluindo Okibacterium e Streptomyces encontrados em Actinobacteria, que foram os gêneros dominantes nas amostras de raízes. No entanto, Streptophyta encontrado em Cyanobacteria/Chloroplast foi o gênero dominante nas amostras de folhas. A análise metagenômica de plantas medicinais leva à identificação de novos organismos ou genes que podem ter um papel na resistência ao estresse abiótico na planta. O estudo da diversidade taxonômica, filogenética e funcional do microbioma endofítico conhecerá melhor os candidatos inovadores que podem ser selecionados como agentes biológicos para melhorar os processos agrícolas e industriais, especialmente para o melhoramento agrícola do deserto.


Asunto(s)
Estrés Fisiológico , Senna , Metagenómica , Endófitos
7.
Appl Opt ; 42(29): 5872-81, 2003 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-14577540

RESUMEN

What is to our knowledge a new scene-based algorithm for nonuniformity correction in infrared focal-plane array sensors has been developed. The technique is based on the inverse covariance form of the Kalman filter (KF), which has been reported previously and used in estimating the gain and bias of each detector in the array from scene data. The gain and the bias of each detector in the focal-plane array are assumed constant within a given sequence of frames, corresponding to a certain time and operational conditions, but they are allowed to randomly drift from one sequence to another following a discrete-time Gauss-Markov process. The inverse covariance form filter estimates the gain and the bias of each detector in the focal-plane array and optimally updates them as they drift in time. The estimation is performed with considerably higher computational efficiency than the equivalent KF. The ability of the algorithm in compensating for fixed-pattern noise in infrared imagery and in reducing the computational complexity is demonstrated by use of both simulated and real data.

8.
J Opt Soc Am A Opt Image Sci Vis ; 20(3): 470-80, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12630832

RESUMEN

A novel statistical approach is undertaken for the adaptive estimation of the gain and bias nonuniformity in infrared focal-plane array sensors from scene data. The gain and the bias of each detector are regarded as random state variables modeled by a discrete-time Gauss-Markov process. The proposed Gauss-Markov framework provides a mechanism for capturing the slow and random drift in the fixed-pattern noise as the operational conditions of the sensor vary in time. With a temporal stochastic model for each detector's gain and bias at hand, a Kalman filter is derived that uses scene data, comprising the detector's readout values sampled over a short period of time, to optimally update the detector's gain and bias estimates as these parameters drift. The proposed technique relies on a certain spatiotemporal diversity condition in the data, which is satisfied when all detectors see approximately the same range of temperatures within the periods between successive estimation epochs. The performance of the proposed technique is thoroughly studied, and its utility in mitigating fixed-pattern noise is demonstrated with both real infrared and simulated imagery.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA