Data Releases:

DR 1 (partial)

DR2 (full, but...)

DR3.1 (currently about 70% of the fields)

DR4 (3,234 of 3,237 fields - fully released for use)

The first data release (DR1) consisted of 578 of the 3,237 fields comprising GPIPS. These were obtained during observing runs in 2010 (May, June, and September) and in 2011 (May). The were processed through software version 7.1.0 of the MSP_PPOL package. They were primarily intended to allow some early access and use of GPIPS data. DR1 has been superceded by DR3.1 [1/31/2017], so DR1 is no longer served out or supported.

The second data release (DR2) includes all of the GPIPS data. They were all processed to the same software standard (v8.2.1 of PPOL) and used the same (updated to March 2014) calibration files. DR2 consists of a number of large zip files, containing typically 3,237 instances of catalogs and/or images or other high-level data products, organized as one file per observed Mimir field. Similarly, DR2 has been superceded and is no longer served out or supported [1/31/2017].

Unfortunately, use of science use of DR2 uncovered some quality control issues that led to addition of a new criterion for acceptance of an observation (the 'Secular Amplitude' - the peak-to-peak change in the slow sky transmission during the course of an observation sequence) and a full examination of all the final images to identify issues not being flagged via software tests. Many observation sequences were reprocessed using PPOL to cure some of the issues revealed, and many GPIPS field observations were rejected. Reobservations of many fields in 2015 replaced most of the problem fields, but not all.

DR3 (12/4/2015) was the best compilation of GPIPS to date and included cleaner versions of many of the images and observational sequences. However, another serious issue came to light when examining the polarization properties of several fields. This was tracked down to be mostly due to problems in HWP rotation within Mimir. Recent mechanical linkage issues in the HWP drive train have been repaired (permanently, we hope). New data quality testing software tools were developed and applied to all of the GPIPS data to detect HWP problems in the data. This, plus visual examination of the polarization patterns in each of the GPIPS fields revealed that about 70% of the fields have no detectable problems.

These 2,257 fields have been returned to this website for external serving as DR3.1 as [1/31/2017]. Another ~10% of the fields required some data editing and reprocessing to achieve the same 'good' status and these will be merged with DR3.1 over the next few weeks (along with some recent reobservations of some fields). Another ~10% of the fields might be able to be repaired, though with more aggressive data editing. If this is successful, those fields will also be merged into DR3.X. Finally, about 10% of the fields do not appear recoverable and must be reobserved, as has been proposed for May and June of 2017. We expect the final, complete GPIPS data set to be available as DR4 by Fall of 2017.

Yet to come will be VO compliance and searchability.

Jump to DR1

Jump to DR2

Jump to DR3.1 (1/31/2017)

Jump to DR4 (1/16/2019)


Publications resulting from use of GPIPS data must include the required acknowledgement (About > Sponsors).