These three satellites operate in a near-polar, sun-synchronous orbit 705 km above the Earth's surface. To evaluate the ALI sensor capabilities as a precursor to the Operational Land Imager (OLI) onboard the Landsat Data Continuity Mission (LDCM, or Landsat 8 after launch), its measured top-of-atmosphere (TOA) reflectances were compared to the well-calibrated Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) and the Terra Moderate Resolution Imaging Spectroradiometer (MODIS) sensors in the reflective solar bands (RSB). As part of the EO- 1 mission, the Advanced Land Imager ( ALI) sensor demonstrates a potential technological direction for the next generation of Landsat sensors. EO- 1 has now been operational for more than a decade, providing both multispectral and hyperspectral measurements. The mission was extended because of the value it continued to add to the scientific community. The Earth Observing- 1 ( EO- 1) satellite was launched on November 21, 2000, as part of a one-year technology demonstration mission. Radiometric cross-calibration of EO- 1 ALI with L7 ETM+ and Terra MODIS sensors using near-simultaneous desert observationsĬhander, Gyanesh Angal, Amit Choi, Taeyoung Xiong, Xiaoxiong The results indicate that the relative sensor chip assemblies gains agree with the ETM+ visible and near-infrared bands to within 2% and the shortwave infrared bands to within 4%. The second approach uses vicarious calibration techniques to compare the predicted top-of-atmosphere radiance derived from ground reference data collected during the overpass to the measured radiance obtained from the sensor. The first approach involves calibration of nearly simultaneous surface observations based on image statistics from areas observed simultaneously by the two sensors. Results have been obtained using two different approaches. To evaluate ALI's capabilities in this role, a cross-calibration methodology has been developed using image pairs from the Landsat-7 (L7) Enhanced Thematic Mapper Plus (ETM+) and EO- 1 ( ALI) to verify the radiometric calibration of ALI with respect to the well-calibrated L7 ETM+ sensor. Cross calibration of the Landsat-7 ETM+ and EO- 1 ALI sensorĪs part of the Earth Observer 1 ( EO- 1) Mission, the Advanced Land Imager ( ALI) demonstrates a potential technological direction for Landsat Data Continuity Missions.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |