Talk:Moderate-resolution imaging spectroradiometer
|WikiProject Spaceflight||(Rated Start-class, Low-importance)|
|WikiProject Meteorology / Data / Instruments||(Rated Start-class, Low-importance)|
The MODIS data processing chain is wanted!
The MODIS data processing chain should also be described.
The short version of the story is, roughly:
- L0 to L1A to L1B:
- the satellite sends a sequence of packets, formatted as per CCSDS recommendations, which are received by the receiving station and, after any duplicate or damaged packets are removed, saved as an .pds file;
- the data is then extracted out of the individual packets to be laid on swath (as in swath width), and an MxD01 (with x being “O” for MODIS/Terra and “Y” for MODIS/Aqua, respectively) file is formed;
- the geolocation is then performed, resulting in an MxD03 file;
- both the geolocation results and the original unpacked data-on-swath (MxD01) are needed to perform the calibration, resulting in an MxD02 — calibrated radiances — file;
- L1B to L2:
- the cloud mask is retrieved (MxD35);
- the atmospheric variables (temperature and moisture profiles, the total amount of the atmospheric gases, etc.) are retrieved (MxD07); there, some ancillary data is used, in particular — the final reanalysis data, as published by NCEP;
- with the atmospheric variables known, the accurate atmospheric correction is performed, resulting in the land surface (i. e., “no atmosphere”) reflectances product (MxD09);
- L2 to L2G to L3:
- the data on swath is first transferred to a kind of “intermediate” grid format, which allows for all the observations (i. e., up to four) of a given pixel of the grid to be saved (MxD09G);
- a number of gridded products are then made, among those are BRDF model parameters (MCD43A1 for the “500 m” grid and MCD43B1 for the “1 km” one), Albedo (MCD43A3 and MCD43B3), etc.; the “C” letter here means that the product combines the data from both the MODIS/Terra and MODIS/Aqua sensors.
(But note that while the scheme outlined above is linear, the actual processing chain is more like a tree, with, e. g., some of the L3 products being all about atmosphere, and thus requiring no MxD09 processing. There're also much more products than mentioned above.)
Unfortunately, I cannot provide appropriate references just now, aside from Математические технологии оперативного регионального спутникового мониторинга характеристик атмосферы и подстилающей поверхности ч. 1. MODIS, which I co-authored.
Also of significance are:
PS. File naming conventions should also be described.
What replaced MODIS?
- Not yet, the satellites are still operational. I'm not sure if NASA has annonced anything to replace the satellites so far. Wonderworld1995268 (talk) 03:29, 5 September 2010 (UTC)
@Tony1: If an article were to be created for the relevant type of spectroradiometry, then I would be more swayed by your move rationale. While the current title is now apparently consistent with Wikipedia's style, I'm not certain this is actually intended to be descriptive title; it is the name of the instrument. This is especially pronounced upon examining the information page here. It reads "Moderate Resolution Imaging Spectroradiometer" with capital letters starting each word, and curiously, it also neglects the hyphen. Is this worth discussing? Dustin (talk) 17:12, 26 December 2015 (UTC)
- @Dustin V. S.: Do you mean the way some scientists/organisations cap every type of spectroscopy? Methinks it's in the mistaken belief that because they're typically expressed with capped initialism, those letters should be capped in the expanded forms (against the advice of the major style guides, and en.WP's). But here, perhaps your point is that this is a specific instrument developed by NASA (which suffers from serious cap-disease—every nut and bolt seems to be capped in their world). If there were more than one of these MODIS's, there'd be no doubt: generic and downcased. If it's the only one, I wonder whether it embraces a measurement phenomenon (moderate-resolution imaging spectroradiometry)? If so, that phenomenon could presumably be the basis of other devices. Sometimes there's a grey area where a commercial product becomes generic (hoovering the carpet; googling). Generally, the trend is to minimise upcasing (according to CMOS and Oxford), although they're not uber-specific about that. Pleased to hear your opinions. Tony (talk) 01:07, 27 December 2015 (UTC)