9/25/2023 0 Comments Matlab tools for oceanThe amount of electron leakage is proportional to the duration of the integration time. A running average of the most recent 15 scans is maintained. Then additional scans are averaged into the correction factor as these spectra become available. Although the algorithm specifies that 15 consecutive scans be averaged, the correction factor is applied as soon as the first spectrum of data becomes available. To eliminate any error due to leakage, electric dark correction computes an average value of these dark pixels over 15 consecutive scans, and then subtracts this average value from all pixels in the spectrum. Due to leakage, a small amount of electrons escape from the detector well even if there is absolutely no light. A dark pixel is an electrically active CCD detector pixel that has been physically coated to prevent any light from entering. Many spectrometers have a small number of dark pixels. Quick tip: There’s a more detailed explanation of boxcar smoothing and its trade-offs in the Glossary section of our Technical Hub. The SNR will improve by the square root of the number of pixels averaged. If the value entered is too high, a loss in spectral resolution will result and peaks will become flattened. The greater the boxcar width value, the smoother the data and the higher the SNR. For example, a boxcar width value of 5 averages each data point with 5 points to its left and 5 points to its right. The SNR will improve by the square root of the number of scans averaged.īoxcar smoothing is a technique that averages a group of adjacent detector elements across spectral data. The higher the value, the better the signal-to-noise ratio (SNR). This time-based averaging function specifies the number of discrete spectral acquisitions that the device driver accumulates before OceanView receives a spectrum. Activating this feature is as simple as selecting the Automatic option in the Acquisition Group Window of OceanView. Quick tip: In OceanView 2.0.8 and higher versions, there’s a convenient feature that automatically selects the integration time appropriate for your setup. When setting integration time, be careful not to allow any pixels to become saturated, as these pixels will not provide useful data. We find that the best measurements are made when the signal intensity is between 80% and 90% of its full range. Integration time is the period of time over which the spectrometer collects photons and correlates with the intensity of the signal that is captured. This is the first parameter that you will set. This is important even if you’re using one of OceanView’s wizards, which guide you through the steps for specific measurements (absorbance, color and so on) but still require you to input most data acquisition parameters. What do I need to know?Ī: Understanding the key data acquisition parameters available in OceanView will help ensure best results for your spectral measurements. Q: I’m getting started in OceanView and don’t understand how best to use the data acquisition parameters that are available. Now, you can save the processed spectrum, background, reference, and sample files when you select “Save graph to files.” One more step is required: to manually add connections from the reference, background and sample, if desired. File Writer allows you to save and export processed date for each graph to an ASCII file.Īt this point, the Aggregate is still only connected to the processed spectrum (Reflection). In this example, your next step is to select “Configure graph saving” to add the Aggregate and File Writer. To save the dark spectrum (background) and reference in Schematic View, you must manually connect the reference and background nodes to the Aggregate node.įor example, here is a reflectance measurement in Schematic View before the Aggregate node is added: The nodes also indicate where data is processed or manipulated. Icons represent different devices and processes in your project as nodes, with data flow represented by arrows and links that connect those nodes. The Schematic View in OceanView presents data from your device(s) in a diagram format.
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