SCR 3-1102 Vote Comments


Ron Joyner

(Betty Sword responds to Todd’s comments:)

I agree with Susie and Anne. I use NASAView frequently, and it is also referenced in many data product SISs as being provided by PDS for viewing those particular data sets.

(Steve Hughes responds to Todd’s comments:)

Regarding active use, the latest download statistics for NASAView are:Jan – 126 Feb – 188 Mar – 142 Apr – 130

There is also an applicable Level 3 Requirement.”3.3.2 PDS will provide a capability for opening and inspecting the contents (e.g. label, objects, groups) of any PDS compliant archival product”

On a related issue, namely the Object Access Library (OAL),

  • Almost all standard widely used data formats have such libraries for reading and writing data. For example the FITS format has FITS I/O libraries and likewise for HDFn, and CDF.
  • The Object Access Library (OAL) fills this role. It was developed by a team led by Randy Davis on contract to the PDS.
  • NASAView is simply a multi-platform GUI that uses the OAL to read PDS data products.
  • When a new data format (data structure) is proposed for the PDS archive the process for approving the new format currently requires that the algorithm for reading the data be implemented in the OAL. This allows NASAView/OAL to be used to validate that the label correctly describes the data object. I.e. If NASAView can open and display an IMAGE or TABLE, then beyond knowing that the label is syntactically and semantically correct, we also know that the data can be read into memory, converted for use on the host platform, and used. (Note: The software includes over 50 routines for converting values between different hardware platforms.)
  • The PDS-D product servers use the OAL for data product transformation. (e.g. PDS-to-JPEG)
  • We can use NASAView/OAL as one indicator for determining the core PDS data formats.


Susie Slavney

(In response to Todd’s comments:)

We use it frequently for images and tables, though it is admittedly clunky. It’s not obsolete until we have something better for its replacement.


Patty Garcia

Yes (to implementation), but as PSDD is currently in the list of optional keywords for the IMAGE object (allowing all legitimate keywords to be used in the IMAGE object), this seems unnecessary. I don’t think we should encourage the proliferation of SCRs that are not really needed.

(In response to Todd’s comments:)

Susie’s comments apply to Imaging as well.


Todd King

My recommendation is that NASAView not be updated unless it is actively used. We don’t use NASAView at PPI, so from our perspective NASAView could be deprecated (no longer changed).


Anne Raugh

SCR 3-1107: (sic) Expand the Optional Keyword list for the IMAGE Object

(Specifically, add LINE_DISPLAY_DIRECTION and SAMPLE_DISPLAY_DIRECTION, with a requirement that NASAView also be updated to recognize and correctly apply these values.)(In response to Todd’s comments:)

As far as I know, NASAView is the only piece of free software out there that can display a raster image with an attached PDS label. As long as PDS is producing such files and there is no outside support, NASAView has to work and work well.