# Presentation: 215300

## Searching: Whither NDG?

- Bryan Lawrence

## Starting position

- Visualisation is nice but once a user has done that a few times, they want the data for themselves.
- They want to be able to bookmark workflow (e.g. “I always want the last month’s climatology picture”).
- Simple hierarchical menus like that provided by LAS simply do not scale (so I have 100+ entities in my menu, how do I deal with that?)

## NERC Metadata Gateway - SST

**Notes:**
On the way through, make the point that the datasets we see are not all the datasets that have SST – we’ll come back to that!
Also make the point that we could have chosen a time or spatial subset when that frame is up.

## NERC Metadata Gateway - SST

**Notes:**
On the way through, make the point that the datasets we see are not all the datasets that have SST – we’ll come back to that!
Also make the point that we could have chosen a time or spatial subset when that frame is up.

## Very Irregularly Copied to GCMD

## ESIP to BADC (and we didn’t do it!)

## DIF Fields

- Some fields are **required**, meaning that the fields must be present in the DIF in order for the DIF to load into DIF databases. These fields are Entry_ID, Entry_Title, Parameters, Data_Center and Summary.
- Other fields are deemed **critical**, meaning these fields are crucially important for data set selection (*i.e.*, searching), user understanding of the data, or data access.
- Fields critical _for searching_ are Parameters, Temporal_Coverage, Spatial_Coverage and Location. If a user conducts a search by these criteria, and the DIF does not contain the information, the DIF will not be found in the search.
- Fields critical for _user understanding_ of the data are Entry_Title, Summary and Data_Resolution. Without these fields, users cannot know if a dataset is appropriate for their needs.
- Lastly, the Data_Center field is critical for users to be able _to access the data_ once they decide the data is appropriate for their needs.

## Examples of what Q metadata must support

- Start Search

- Observations

- Simulations

- Type of Model (e.g. UM)

- When Run?

- Who by?

- Why (e.g. 2xCO2)

- Specific Times

- Code Base (e.g Kuo Param)

- Specific Experiment

- 1d-4d slice: **A-type **metadata object

- Field Campaign  or Cruise

- Platform

- Instrument

- Observation Period

- Parameter Observed

- Phenomena Observed

- Geographic Location

- Parameter

- Algorithm

- Not exclusive! Very complex routing!

## NDG version of Bob’s ESG Object Model

- Ensemble

- Simulation

- Aggregation

- Project

- Dataset

- Operational

- Campaign

- Platform

- Instrument

- DataFile

- B-Attributes

- A-Attributes

- For the moment, collapsing the inheritance of CF variables into the (netCDF) Data File.

- Defining TWO types of attribute

## Slide 10

## Slide 11

## Slide 12

## We can select information from previous pages.

-  People usually complain when selecting means loosing information and have to go back to choose options not available from the current page

## All these pages are drawn dynamically on the fly as we browse the catalogue

## ... getting to the data 

- ... getting to the data

## Bottom  Line

- Simple (google-like)
- Re-entrant (bookmarks)
- Scripting basis (gui decoupled from functionality)
- Dynamically generated
- Deliver data first, worry about visualisation second
- Avoid traversing deep hierarchies where possible or presenting the user with lengthy lists (more than 10 items).
- Simple!

## FGDC CSDGM sections

**7 Main Sections**

**Description**

- *

***Identification***

*title, description, subject*

- Data Quality

*accuracy, processing*

- Spatial Data Organization

*vector, raster*

- Spatial Reference

*projection, depth*

- Entity & Attribute

*features, values*

- Distribution

*ordering point, media*

*******

***Metadata Reference***

*date written, author*

****Required sections***

_**3 Supporting Sections**_
- Citation (reference)
- Time Period
- Contact

## Directory Interchange Format (DIF)

- A de-facto standard for directory entries which describe a group of data.
-  DIF consists of a collection of fields which detail specific information about the data. Five fields are required in the DIF; the others expand upon and clarify the information. Some of the fields are text fields, others require the use of valid values.
- The DIF allows users of data to understand the contents of a data set. The DIF contains those fields which are necessary for users to decide whether a particular data set would be useful for their needs.
- The DIF is compatible with Federal Geographic Data Committee's (FGDC) Content Standard on Digital Geospatial Metadata (CSDGM).
- The compatible content allows fields to be mapped. With the mapping, FGDC CSDGM records can be converted into DIF and vice versa.