exemplo de calculo

Anais XVI Simpósio Brasileiro de Sensoriamento Remoto - SBSR, Foz do Iguaçu, PR, Brasil, 13 a 18 de abril de 2013, INPE

Avaliação da propagação de erros ao utilizar a aproximação de Wien na linearização da lei de Planck
Atilio Efrain Bica Grondona1,2
Silvia Beatriz Alvez Rolim1
Matheus Pinheiro Ferreira1
Bijeesh Kozhikkodan Veettil2
Maria Lujan Iglesias1
1

Universidade Federal do Rio Grande do Sul - UFRGS
Centro Estadual de Pesquisas em Sensoriamento Remoto e Meteorologia (CEPSRM)
Av. Bento Gonçalves, 9.500 – 91501-970. Caixa Postal 15.044
Porto Alegre, RS/Brasil
{atilio.grondona, silvia.rolim}@ufrgs.br; [e-mail]; [e-mail]
2

Codex Remote – Ciências Espaciais e Imagens Digitais
Av. Borges de Medeiros 659, Conj. 503 – Porto Alegre - RS, Brasil
{atilio, bijeesh}@codexremote.com.br
Abstract. Temperature and emissivity are among the major physical properties of materials which are studied using thermal infrared images. Many methods for temperature and emissivity retrieval are based on linearization of Planck’s law though these approximations are subjected to errors. This paper describes the propagation of errors in the linearization of Plank’s function using Wien’s approximation. The relationship between radiance and temperature is non-linear and the temperature emissivity separation is a complex task. Linearization is a technique that mitigates this problem. The data used for this study were obtained using a µFTIR field spectroradiometer from a quartz sample under controlled conditions. The instrument is calibrated using cold and hot blackbodies and the sensor is calibrated with a Lambertian surface. The emissivity is calculated using the
Plank’s function and the temperature for a radiance measured in a given wavelength. Other sources of errors such as atmospheric effects were not considered here. Possible errors in temperature, emissivity and wavelength were analyzed. To solve the problem of multiple variables, Wien’s approximation is