Investigation of P2 duplicates issues

Introduction

One of the duplicates issues in PSPS occurs with duplicate objID within a P2 batch. During ipptopsps batch creation, we remove duplicates within each OTA. However, there are instances where there are duplicate objID that occur in 2 adjacent OTAs.

One of the examples is objID 78302606220962865 in batch B01387864 - PSPS kicked this batch back to us, stating that objID 78302606220962865 was duplicated within that batch.

I downloaded the batch, and investigated it. I found that the objid was in 2 adjacent OTAS (23 and 33). If I plot ra vs objid and color the 2 OTAs differently, I get the following plots:

first, a plot of ra vs dec:

Then a plot of ra vs objID (with red on top)

A plot of ra vs objID (with blue on top)