I would like to present CERES raw TOT DET (ToTal DETector output) from TOA (Top Of Atmosphere) from the time periods of 2000-2005 and compare 2010-2015 data on a WGS84 model. I would also like to know if it is possible for SSE to extract this data from the BDS (Bi-Directional Scan) HDF file, without having to strip the data and import with Xcel.
Once this is accomplished, I would like to add MODIS and MIST imagery to give more detail to the energy balance from surface to the top of the atmosphere. The software I have is: HDFView, MINX, MISR, and UNIX software (that came with the CERES BDS scans) - I have trouble with the UNIX - no past experience with programming.
Bidirectional Scan Information
Detailed information on the CERES BDS can be found in the Collection Guide (http://ceres.larc.nasa.gov/documents/co ... G_R3V4.pdf)
The data in the CERES BDS TOA and surface coordinates are geodetic and based on the WGS84 model. CERES has carried over from the Earth Radiation Budget Experiment convention to use colatitude instead of latitude. Colatitude starts at the North Pole with a value of 0 and terminates at the South Pole at 180 (Lat = 90 – CoLat).
The BDS includes raw counts, drift corrected counts, and filtered radiance for the total detector output. Even though the filtered radiance has been converted to physical units of W m-2 sr-1, the filtered radiance does not take into account the spectral losses that occur in reflection and absorption at the detector.
Other CERES Products that May Support Analysis
The unfiltered radiance, corrected for less than 1.0 spectral response, is available on the hourly CERES Single Scanner Footprint (SSF) file. Before the radiances are unfiltered, the shortwave component is subtracted from the total channel to obtain a longwave radiance. To determine the total energy departing at the Earth TOA, the shortwave and longwave need to be combined.
The unfiltered radiance still contains directional dependences based on the instrument and solar geometry. These are removed by applying Angular Distribution Models to generate SW and LW fluxes (W m-2). The TOA fluxes are contained on the SSF also. Parameterized surface fluxes and cloud properties are also contained on the SSF.
The SSF is an hourly footprint level product that contains unfiltered radiances, TOA and surface fluxes, cloud properties, and MODIS radiances. Only Earth viewing footprints are included in this product.
If actual footprint resolution data is not needed for the study, CERES has several gridded products. Created from the hourly SSF, there is SSF1deg-Hour that contains spatially averaged 1o Longitude by 1o Latitude (360 x 180) TOA fluxes and cloud properties for each hour of the day in daily files. The SSF1deg-Day and SSF1deg-Month have time interpolation to produce daily and monthly average fluxes and other parameters.
CERES also produces the Synoptic one-degree product, SYN1deg, that combines CERES instruments from the morning and afternoon overpasses along with geostationary imager data to determine the diurnal cycle of the fluxes. The Fu-Liou radiative transfer model is used to produce surface fluxes and in-atmosphere fluxes at 500, 200, and 70 hPa.
There is also the Energy Balanced and Filled, EBAF, data set that only contains TOA fluxes but adjusts for the ocean heat storages and provides clear sky values for all grid boxes.
Mar 31, 2016
The BDS is a daily footprint-level product that contains 13,091 scan lines made of 660 footprints per scan line. Not all these footprints are Earth viewing. These daily files average 655 MB with compression used. It is just not feasible to provide the data in ASCII.
The CERES team has provided view_hdf, an IDL-based reader and visualization tool, for HDF4 products (https://asdc.larc.nasa.gov/documents/tools/view_hdf.pdf). It uses the IDL virtual machine that can be obtained free of charge as described in the document. This package will let you dump a variable to an ASCII file.
Since CERES and MISR products are delivered in HDF, the MISR tools should work with CERES, but have not been tested.
Other commercial packages that allow HDF data manipulation are MatLab and IDL. The open source Python also provides an HDF library for manipulating the data.
The CERES ordering tool provides the ability to visualize and subset data products and can be reached here: http://ceres.larc.nasa.gov/order_data.php. Subsetted products from this tool are delivered in netCDF. There is also the ability to download the data behind a given image as an ASCII text file. If you only need values for a given region, you can subset the data for that region, visualize one of the months, select time series, and then download the data as ASCII.
Mar 31, 2016
Thanks very much for the feedback!
I am also interested in the instrumentation - specifically the bolometer and calibration protocols - I understand TRW performed the assembly and calibrations - is there any documentation I can easily access?
Apr 01, 2016
TRW was the original instrument manufacture and performed the calibration work. The team is now part of Northrop Grumman Aerospace Systems.
CERES publications can be searched at http://ceres.larc.nasa.gov/ceres_library_search.php
These articles may have the information you requested.
Jarecke, P. J.; Folkman, M. A.; Hedman, T. R.; Frink, M. E. (1993)
Clouds and the Earth's Radiant Energy System (CERES): Long-wave Calibration Plan and Radiometric Test Model (RTM) Calibration Results
Metrologia, 30(4), 223. http://dx.doi.org/10.1088/0026-1394/30/4/003
Lee, R.B.; Barkstrom, B.R.; Bitting, H.C.; Crommelynck, D.A.H.; Paden, J.; Pandey, D.K.; Priestley, K.J.; Smith, G.L.; Thomas, S.; Thornhill, K.L.; Wilson, R.S. (1998)
Prelaunch calibrations of the Clouds and the Earth's Radiant Energy System (CERES) Tropical Rainfall Measuring Mission and Earth Observing System morning (EOS-AM1) spacecraft thermistor bolometer sensors
IEEE Transactions on Geoscience and Remote Sensing, 36(4), 1173-1185. http://dx.doi.org/10.1109/36.701024
Apr 13, 2016
Thanks very much for the info - but do you have a copy of this information that I don't have to pay for?
I'm also interested in the Quality Assurance report for the radiometer instrumentation.
Apr 16, 2016
This document may be of interest to you.
The Quality Assurance Guidance for the Collection of Meteorological Data Using Passive Radiometers:
https://cfpub.epa.gov/si/si_public_file ... _id=508342
Apr 26, 2016
However, there may be some documents listed that "reside" in a specific commercial documentation service, which MAY charge a fee.
If you have tried to get documents and have been unable to obtain them for free, please let us know which ones and we will try to get a free copy to you.
Apr 26, 2016