NRAO Home  >  Green Bank  |  Wiki Topic:    GB > Software > SddMetrics > MetricsC42007

Changes | Index | Contents | Search | Statistics | Go

Software Development Metrics & Information Summary for C4 2007

16 May 2007 through 30 June 2007

The Plan of Record used for this cycle can be found at PlanOfRecordC42007.

• Overview
  • Project Allocation
  • Cycle Commitments
• Operational and User Support
• Commitment Highlights
  • Evolve Dynamic Scheduling Proposal
  • Business Office System
  • Update Pointing/Focus code to Handle Old Data Sets
  • Analysis of Trajectory Generation Problems
  • Inclinometer Improvements
  • Implement PFM5 revised Pointing/Focus Model
  • Port Holography Manager to Linux
  • Modify Peak Finding Algorithm for Pointing/Focus Code
  • Complete GBT Spectrometer Cross-Polarization Documentation
  • Future Pulsar Backend
  • Data Analysis Planning
  • RFI Database
  • Continuing Education
  • Division Administration & Planning

Overview

Project Allocation

The cycle commitments were allocated over 10 major projects: Dynamic Scheduling, PTCS, Business Office System, Spectrometer, Software Continuing Maintenance and Enhancements (CM&E), e2e, Future Pulsar Backend, Zpectrometer/Ka Receiver, Mustang, and RFI. In the chart below, "other" is used as a catch-all for those cycle commitments which are not associated with a major project.

The projects are further broken down into the individual commitments in the next section.

Cycle Commitments

The cycle commitments for C4 consisted of 23 commitments. A summary of each major commitment is discussed later in its own section. Of the 28 commitments, 26 were met satisfactorily (of these 20 were part of larger efforts which will continue into future cycles). 1 were not completed as expected and continued over into the next cycle. The following commitments were not completed as expected: Complete Documentation of Cross-Polarization Changes - this is written and pending review.

Operational and User Support

The items listed below pertain to time spent supporting GBT operation. These tasks usually involve helping users, fixing/troubleshooting system problems, and fixing/troubleshooting lab test environment problems. Note: Effort estimates reflect total time elapsed, i.e. how long did it take to fix the problem start to finish - not the sum total of each person's time. Operational and User Support was minimal this cycle due to the GBT azimuth track shutdown.

Items:

• date - who - what - how long? (low, medium, high)
• 5-7/6/2007 JoeBrandt - Addressed hardware problems with antenna simulator. medium
• 4-7/6/2007 JoeBrandt - Support for air conditioning shutdown. medium
• 7-8/6/2007 RamonCreager - Patched Grail to fix resource starvation on fire. medium
• 14 Jun 2007 MarkClark - Turned Spectrometer on via glish for operator while CLEO not working. low

Key:

• low - Things that take less than two hours.
• medium - Things that take more than two hours, but less than eight hours.
• high - Things that take more than eight hours.

Commitment Highlights

Evolve Dynamic Scheduling Proposal

Information on the Dynamic Scheduling project can be found at the Dynamic Scheduling Project Page and Dynamic Scheduling Web Home. The effect of weather conditions, both wind and opacity, on high frequency astronomy is well known. Currently, the GBT is using a fairly basic dynamic scheduling system which neither allow for rapid changes in the weather nor for long spells of good or bad weather. To maximize our use of good weather, we need to implement a true dynamic scheduling system on the telescope. The design and implementation of such a system is the goal of this project. This cycle, the Dynamic Scheduling Project underwent an internal staff review and an external conceptual review.

This task was allocated ~388 person-hours of effort, but expended ~447. We underestimated the amount of work required to prepare adequate review materials. This task will be continued into next cycle and throughout 2007. Next cycle, the effort will slow down due to the Ka-band receiver and Mustang preparations for high frequency season.

Business Office System

The creation of an NRAO-wide reservation system is aimed at consolidating the disparate systems used in Green Bank and Socorro for visitor accommodations and support. The name of the system has been changed to the BusinessOfficeSystem because the project now involves more than just reservations.

This cycle, we continued implementation of five Modification Requests which capture all of the changes necessary to deliver a viable Business Office System for both the Socorro and Green Bank Business Offices. We are aiming for deployment of the final system later this year. We executed two rounds of sponsor testing on the system. We are currently working to resolve issues found during sponsor testing and to create an administrator's manual for the system. We will develop a final plan for deployment next cycle.

We allocated ~374 person-hours of effort for this task and expended ~398.

Update Pointing/Focus code to Handle Old Data Sets

Sparrow applications (e.g., PrePoint, GFM) should be able to process older datasets. Specifically, they should successfully process datasets for configurations using multiple beam receivers, where the tracking beam is 'C' representing a 'center' beam, but where scans may be collected with beams other than 'C'. However, some applications were having problems recognizing certain beam designations from older projects. This effort is aimed at providing support in current applications for these beam designations.

We expended ~0.5 peron-hours of effort completing this task this cycle. The modification has been patched into the system software.

Analysis of Trajectory Generation Problems

For some time now the Antenna Manager has had issues which result in the production of transient spikes in commanded acceleration. These spike occur whenever there is a discontinuity in velocity, or a jump in position. At times, the dynamic correction updates are enough to produce notable spikes, but by far the most spikes are generated from step changes in velocity when transitioning off slew trajectories. A second condition is present which produces acceleration spikes. The condition is due to an assumption which is made by the trajectory algorithm, which is that both starting and ending accelerations are of equal magnitude. To date, the spikes have had little effect upon performance. The spikes are too narrow for the position loop to respond, and simply are filtered out. However, in an effort to improve tracking performance, the servo group is investigating the use of friction compensation and acceleration feed-forward. This effort will rely upon a clean acceleration command stream, because the commands will be presented directly into the current loop. This effort is directed at removing the transient spikes in the commanded acceleration.

We expended ~6 person-hours of effort for this task this cycle. Most of the effort for this task was diverted to the development and implementation of a new pointing model. This item will continue into the next few cycles as part of the PTCS project.

Inclinometer Improvements

There have been reports from the PTCS group of problems with the recorded inclinometer data, which are noted as: (1) The device data timestamp is either duplicated for two different data samples, or filled in as NaN values, (2) the device data fields are filled as NaN values, (3) increased accuracy of time-tagging is desired, and (4) decreased error rates are desired. This MR is continued from last cycle.

The MR passed sponsor testing and has been patched into the system software.

Implement PFM5 revised Pointing/Focus Model

This Modification Request details the work to be done to incorporate a new pointing and focusing model in the antenna manager. The changes related to this work will be released for tests on or before August 1st, 2007.

We allocated ~49 of person-hours for this effort and expended ~54 person-hours this cycle. This item will continue into the next cycle as part of the PTCS project.

Port Holography Manager to Linux

The holography backend was originally deployed years ago on a VxWorks system with an MCB interface. The system was limited to 200 ms dumps due to the combination of the VxWorks OS and the MCB interface. We need the backend to dump much faster in order to properly map the GBT's panels. A new host platform and operating system is required (Linux), and a new interface to the data stream and the command stream will be created. No new manager parameters or sampler values will be needed, that is, the external interface to the M&C system will remain unchanged, except for the volume of data recorded, and the legal command values for integration time.

We allocated ~141 of person-hours for this effort and expended ~119 person-hours this cycle. This item will continue into the next cycle as part of the PTCS project.

Modify Peak Finding Algorithm for Pointing/Focus Code

When processing "Peak" or "Focus" scans, the algorithm that GFM uses to find the first guess for the location of the peak seems to be very robust when doing peak scans with the standard scan length and rate. But if one uses very different sample rates or scan lengths, the algorithm sometimes fails to find the correct peak. This MR implements some changes to allow GFM to find a good first guess for the peak position under a wide variety of circumstances. Of course, it is important that the performance for standard Peak scans is not degraded.

We allocated ~68 person-hours of effort for this item and expended only ~55.5. The MR is currently tabled. The PTCS group has settled on a final approach to solve this issue. However, since this approach changes the resultant pointing offset values, deployment of the selected approach will be postponed until after the new pointing model is implemented this summer (ModificationRequest1C407).

Complete GBT Spectrometer Cross-Polarization Documentation

The GBT Spectrometer records correlation data for both auto-correlation (correlations between the same sampler) and cross-correlations (correlations between different samplers). Only half the correlation is produced (positive lags). The correlations are transformed from the lag (time) domain to the frequency domain. The treatment is correct for the auto-correlation case, but incorrect for the cross-correlation case. Cross-correlation is also referred to as cross-polarization because the two samplers come from the two polarizations of the same feed and IF (e.g. X and Y or R and L).

We allocated ~46 person-hours of effort to complete this task and expended ~41 person-hours of effort. This task was continued from last cycle and will continue into next cycle. The documentation is currently being reviewed and will be complete soon.

Future Pulsar Backend

A new activity related to this effort started this cycle. JoeBrandt is exploring the possible uses of GPU-technology for pulsar data acquisition and post processing. He presented a series of lunch talks on the issue - GPU Series 1: Triangles to Pixels and GPU Series 2: GPU Programming - How to Ride the Beast.

Data Analysis Planning

The goal of this activity is to evaluate the current effectiveness of the GBT data reduction package, GBTIDL, identify its current deficiencies, and to plan for the future of GBT data reduction. We expect this effort to continue into the coming cycles and evolve into an effort to implement the recommendations which sprout from the analysis. We allocated ~162 person-hours of effort for this task and only expended ~50. Not much was done on this effort due to unanticipated excused absence and preventive maintenance.

RFI Database

Provide a web-based RfiDataBase according to the specifications in a concept document provided by the RFI Group. The RfiDataBase will enable both observers and the RFI group in the following ways:

• The Known Sources Table will serve the RFI Group as a central repository for knowledge about interference that has been seen on the Green Bank site AND has been positively identified. It will serve observers as the database from which other applications, such as the KnownSourcesDisplayIdLprogram can extract pertinent, up-to-date RFI information. Observers can also use this information pro-actively in the planning stages of their observations.
• The RFI Reports Table will be filled by a Web-based form which requests specific parameters the RFI group needs to know about the interference. This helps observers by letting them know what we need, and helps the RFI group by providing sufficient information to begin the RFI identification process. It will also provide a history of RFI reporting.

We are providing a low level of support for this effort and have added an REU student to the project. We expended ~18 person-hours of effort on this task this cycle.

Continuing Education

This cycle's continuing education time included a project management training course attended by four members of the SDD.

Division Administration & Planning

Actual time spent on this effort was much less than anticipated due to large amounts of excused leave by the division head.