Written by Carl Zimmerman, PhD, GIS Coordinator, CT GIS Office (email: carl.zimmerman@ct.gov)
We are all excited about the arrival of the new data and we have received questions about when it will be available. The very high resolution and quality of both the aerial imagery and Lidar create VERY LARGE files which are time-consuming to process and review. Because of this, new vendor workflows and algorithms were required and took some extra time. We know that new imagery is a top priority and the order of dataset delivery has also been altered so that imagery is received first. We are working as fast as possible while maintaining the highest data quality.
The following describes the delivery and timeline and we will provide updates when available.
Delivery Blocks
The data is broken into four delivery sections: northwest CT (light blue, first), southwest CT (dark blue), the CT River Valley (green), and finally eastern CT (brown).
Schedule
Unfortunately, there is no instant gratification in the schedule. The tasks that need to be completed before the data can be finalized and provided include the review, acceptance of edits, final delivery, and then public access. Each step takes some time – there are over 20,000 imagery tiles, billions of Lidar classified points, and over a million buildings.
If you are interested in helping to review the datasets for your town or region, please reach out. There will be a web portal and we will have some training soon to demonstrate its use.
| Tentative data schedule | Block 1 Northwest CT |
Block 2 Southwest CT |
Block 3 Central CT |
Block 4 Eastern CT |
| Imagery | ||||
| 1. Initial data delivery via online review tool | 12/8/2023 | 1/19/2024 | 2/28/2024 | 3/31/2024 |
| 2. Data review* (QAQC**) deadline | 1/10/2024 | 2/14/2024 | 3/27/2024 | 5/1/2024 |
| 3. Final imagery delivery to GIS Office | 1/25/2024 | 3/1/2024 | 4/15/2024 | 5/15/2024 |
| Lidar and GIS Data | ||||
| 4. Initial data delivery via online review tool | 1/31/2024 | 2/29/2024 | 4/30/2024 | 5/31/2024 |
| 5. Data review* (QAQC**) deadline | 3/1/2024 | 4/1/2024 | 6/1/2024 | 7/1/2024 |
| 6. Final Lidar and GIS data delivery to GIS Office | 4/1/2024 | 5/1/2024 | 7/1/2024 | 8/1/2024 |
*Data review will be lead by the GIS Office with help from the Data Acquisition Working Group and stakeholders
**QAQC stands for Quality Assurance and Quality Control