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Susie Slavney

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  1. The first of several LRO Diviner Regional Cumulative Products (RCP) has been released. This is the first Diviner product to use the PDS4 standard.
  2. Answers from the Diviner science team to questions from a Diviner user. Q: The radiance unit mentioned in the lbl file is W m**-2 sr**-1, the term corresponding to frequency is missing. Why is it so? A: Radiance has units of W m**-2 sr**-1 and does not include a frequency term,units of spectral radiance include frequency. Q: How are the BT values calculated from radiance? Are there any preprocessing steps involved in this calculation? Simple calculation using the Planck's function (for the central wavelength) does not match the BT values given in the file. A: The spectral radiance is integrated across the spectral passbands. The Diviner channel spectral responses are described in: Paige, D. A., Foote, M. C., Greenhagen, B. T., Schofield, J. T., Calcutt, S., Vasavada, A. R., et al. (2010). The Lunar Reconnaissance Orbiter Diviner Lunar Radiometer Experiment. Space Science Reviews, 150(1–4), 125–160. https://link.springer.com/article/10.1007/s11214-009-9529-2
  3. Mars 2020 Release 1 includes raw, calibrated, and derived data from sols 0 through 89, February 18 through May 20, 2021, for the Mastcam-Z, MEDA, MOXIE, PIXL, RIMFAX, SHERLOC, SuperCam, Helicam, and EDLCam instruments. Visit https://pds-geosciences.wustl.edu/missions/mars2020/index.htm for details.
  4. Geosciences Node data for InSight Release 9 are online at https://pds-geosciences.wustl.edu/missions/insight/index.htm. This includes data for RISE, RAD, IDA, and SEIS.
  5. There is a one-to-many mapping from dataless SEED files (and StationXML files) to the miniSEED files (and GeoCSV files). In the PDS label for each miniSEED file there is a pointer to the dataless SEED that was delivered with it. Look for the attribute <insight:metadata_file_name>. The dataless SEED files are cumulative, and you are encouraged always to use the latest ones, even if the label indicates an earlier version. The collection inventory is not guaranteed to be in any particular order, although typically new files are added to the bottom with each delivery.
  6. Hi Kevin, The file naming scheme is documented in the InSight SEIS Software Interface Specification section (https://pds-geosciences.wustl.edu/insight/urn-nasa-pds-insight_documents/document_seis/seis_sis.pdf). The number you indicate in the file name is the revision of the miniSEED file. This is the revision internal to the SEIS science team, as they may go through several revisions before the data file is delivered to PDS. If we receive multiple products for which everything in the file name is the same except this revision number, we consider them to be separate products and we archive them all. You ask how to know the revision number ahead of time. You'll find a list of all the products in a collection in the collection inventory. For the SEIS data_seed collection, which includes the SEED and miniSEED files, the collection inventory is here: https://pds-geosciences.wustl.edu/insight/urn-nasa-pds-insight_seis/data/collection_data_seed_inventory.csv As you may know from reading the documentation, every SEED or miniSEED file has an equivalent ASCII text file. The ASCII-equivalent file for a SEED product is a StationXML file. The ASCII-equivalent file for a miniSEED product is a GeoCSV file. These are in the data_table collection, and its collection inventory is here: https://pds-geosciences.wustl.edu/insight/urn-nasa-pds-insight_seis/data/collection_data_table_inventory.csv In these inventories, you'll see that each product is listed by its unique Logical Identifier with Version Identifier (LIDVID), like this: P,urn:nasa:pds:insight_seis:data_seed:xb.elyse.03.bhu.2019.042.11::1.1 The "P" means this product is a primary member of the collection. You can ignore it. The final "::1.1" is the Version Identifier (VID). This is the PDS version number, which is unrelated to the SEIS internal revision number discussed above. The first PDS version of every product is 1.0. In this example, 1.1 indicates that there has been a minor revision, probably a change to the PDS label. The inventory does not include the directory path to each file, but you can figure it out. For example, from the product identifier xb.elyse.03.bhu.2019.042.11, you can assume that product is found in the directory data/xb/continuous_waveform/elyse/2019/042/. Both the miniSEED file and the ASCII-equivalent file are in that directory, along with their PDS labels in XML files. I hope this helps. Susan Slavney
  7. Geosciences Node data for InSight Release 7 are online at https://pds-geosciences.wustl.edu/missions/insight/index.htm. This includes data for RISE, RAD, IDA, and SEIS.
  8. Geosciences Node data for InSight Release 6 are online at https://pds-geosciences.wustl.edu/missions/insight/index.htm. This includes data for RISE, RAD, IDA, and SEIS.
  9. Jee, 1. Yes. 2. To assign each pixel a latitude and longitude, you will need the information in the IMAGE_MAP_PROJECTION part of the label, and also the file DSMAP.CAT in the CATALOG directory of the archive (or DSMAP_POLAR.CAT if you are working with an image in polar stereographic projection). DSMAP.CAT is a text file that gives the details of the simple cylindrical map projection, including the equations to go between latitude-longitude and line-sample. The IMAGE_MAP_PROJECTION keywords in the label give you the values to plug in to those equations for that particular image. 3. The data are in 16-bit signed integers because some of the values are negative. Even after applying the scale and offset there will be negative values, representing elevation below the defined planetary radius, as explained in the note in the label.
  10. Geosciences Node data for InSight Release 5 are online at https://pds-geosciences.wustl.edu/missions/insight/index.htm. This includes data for RISE, RAD, IDA, and SEIS.
  11. Jee, The IMG files are just binary arrays, nothing complicated. The label file that accompanies each image file gives the information your software needs to read the file. For instance, in LDEM.LBL in the IMAGE object, you'll see these lines: LINES = 720 LINE_SAMPLES = 1440 MAXIMUM = 21008 MINIMUM = -17758 SAMPLE_TYPE = LSB_INTEGER SAMPLE_BITS = 16 UNIT = METER SCALING_FACTOR = 0.5 OFFSET = 1737400. This tells you the image array has 720 lines with 1440 samples (pixels) in each line. (The pixels should be displayed from left to right, top to bottom.) Each pixel is a 16-bit signed least-significant-byte-first (little-endian) integer. To go from pixel value to meters, multiply the pixel value by 0.5 and add 1737400. The range of values in the array is from -17758 to 21008 meters. See also Frequently Asked Questions About LOLA Data.
  12. As June says, the data values are int16, signed 16-bit integers. I think your fread statement looks correct, although I am not a Matlab user. The PDS3 label says SAMPLE_TYPE = LSB_INTEGER, which is defined as a signed integer in the PDS3 data dictionary, although it would have been helpful if the label explicitly declared the samples to be signed. You may assume that LSB_INTEGER and MSB_INTEGER in PDS3 labels always mean signed integers. LSB_UNSIGNED_INTEGER and MSB_UNSIGNED_INTEGER are used when the values are unsigned.
  13. MISSING_CONSTANT is the value used to indicate that no actual data value exists; that is, the data value is missing. It does not make sense to apply the SCALE and OFFSET to these pixels. Pixels with this value should be omitted from computations. The value that indicates "missing data" is chosen to be outside the expected range of actual data values. The PDS3 Data Dictionary defines MISSING_CONSTANT as follows: "The missing_constant element supplies the value used to indicate that no data were available." (https://pds.nasa.gov/datasearch/subscription-service/SS-20200212.shtml). Examples of its use are given in the PDS3 Standards Reference (https://pds.nasa.gov/datastandards/pds3/standards/sr/StdRef_20090227_v3.8.pdf).
  14. The SKYV* files are in the EXTRAS directory, which means they are not part of the official LOLA PDS archive, and therefore not peer reviewed. They are extra material that users may find interesting or helpful as an addition to the standard data products. For the product you mentioned, SKYV_65N_240M, there is an equivalent IMG product in http://imbrium.mit.edu/EXTRAS/ILLUMINATION/IMG/. According to its label, it is a binary array of 6420 by 6420 16-bit LSB signed integers (LSB = least-significant-byte-first = "little-endian"). To go from the DN value to solid angle in steradians, you apply the formula DN*SCALING_FACTOR+OFFSET, where SCALING_FACTOR is 0.0002 and OFFSET is 6.2832.
  15. Hi, I don't see any product in the LOLA archives with the name SKYV_65N_240M_JP2. Can you give me the URL where you found it? In general, the JP2 files are JPEG2000 images. You won't be able to read them easily in MATLAB. In the LOLA archives, JP2 images are included only for ease of displaying the data. For every JP2 file there is a corresponding IMG file containing the same data in plain raster format, which is readable in MATLAB. The OBJECT = IMAGE section of the label (*.LBL file) tells you the information MATLAB needs to know to read the file, such as number of lines, number of samples per line, size of a sample, and sample type (byte order).
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