> For the complete documentation index, see [llms.txt](https://satdocs.hydrosat.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://satdocs.hydrosat.com/changelog.md).

# Changelog

A list of product updates, including release dates and key features.

{% updates format="full" %}
{% update date="2026-10-07" tags="platform" %}

## Full Resolution Previews in Discovery Portal

For data you have download access to, including evaluation data, you can now see that imagery in full preview resolution on the map, to make understanding the data easier at a glance.

When zoomed in, there is now a clear visual indicator for imagery that is not available to you in full preview resolution. You can contact our sales team at <sales@hydrosat.com> for access to downloadable data.

<figure><img src="https://3702723385-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FBgOfOR7RYuK5Fm69JAWF%2Fuploads%2FPLu5mB0hHKJyGcJxBIv5%2Fpreviews.png?alt=media&amp;token=9c388ff5-e0a0-4a27-9ed8-15e0d077cb43" alt=""><figcaption></figcaption></figure>
{% endupdate %}

{% update date="2026-09-30" tags="platform,product-update" %}

## Nighttime Imagery Now Available

Nighttime thermal imagery is now available in Hydrosat's Discovery platform within the `vz-liri-l1a-night` and `vz-l1b-night` STAC collections.

To learn more about our nighttime products, see [Product Details](/thermal-data/product-details.md).

<div data-with-frame="true"><figure><img src="https://3702723385-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FBgOfOR7RYuK5Fm69JAWF%2Fuploads%2FUDvVxvKESWJ8fzUdMumU%2FScreenshot%202026-10-05%20at%2010.09.46%E2%80%AFAM.png?alt=media&amp;token=1b8c3dea-b2cd-4e3a-8c39-f720fc74c281" alt=""><figcaption><p>Nighttime imagery visualized in the Discovery portal.</p></figcaption></figure></div>
{% endupdate %}

{% update date="2026-09-08" tags="quality-control" %}

## Image Quality Logs

Quality logs are now available in STAC item metadata (`hydrosat:quality_log`).

These logs offer more context about acquisition and processing conditions so that users can better understand quality characteristics across scenes.

| Quality Log                          | What It Means                                                                                    |
| ------------------------------------ | ------------------------------------------------------------------------------------------------ |
| `Insufficient illumination for VNIR` | The sun's elevation was low during acquisition. This may reduce the quality of the VNIR imagery. |
| `Geolocation out of spec`            | Geolocation for the scene does not meet the expected accuracy.                                   |
| `Georeference failure`               | The nominal georeference procedure did not complete as expected.                                 |
| `Extreme cold values clipped`        | Some pixels contain fill values. Use the `QUALITY_ASSURANCE` mask for details.                   |
| {% endupdate %}                      |                                                                                                  |

{% update date="2026-08-25" tags="cloud-mask" %}

## Cloud Mask Improvements

We've deployed a new version of our cloud detection model using a significantly larger and more diverse training dataset. This results in fewer false positives in the cloud mask and improved detection performance across a wider range of cloud conditions.
{% endupdate %}

{% update date="2026-05-21" tags="processing" %}

## Footprint Geometry Correction

We've deployed a minor fix to ensure representativeness of STAC item footprint geometries with actual imaged area.
{% endupdate %}

{% update date="2026-03-31" tags="processing" %}

## Coregistration Improvements

We've refined our mutual information-based coregistration workflow for improved feature matching between the LWIR and VNIR data.
{% endupdate %}

{% update date="2026-02-24" tags="processing" %}

## Geometric Processing Improvements

We've updated our georeferencing and VNIR band alignment workflows to improve geolocation accuracy and band-to-band registration. This release includes:

1. An enhanced optical distortion correction to reduce residual along-track offsets
2. Use of a digital elevation model (DEM) to improve band-to-band registration over complex terrain
   {% endupdate %}

{% update date="2026-02-05" tags="product-update" %}

## Level-1 Unit Changes

We've modified the units for our Level-1A and Level-1B data products.

#### Before The Change

Previously, L1A and L1B imagery assets contained per-band digital number data. To arrive at radiance, the user needed to apply gain and offset coefficients provided in product metadata.

#### After The Change

**Level-1A Products**

* L1A imagery assets now natively contain per-band top-of-atmosphere (TOA) radiance values. Gain and offset coefficients are applied as part of Hydrosat's data processing.
  * Units: W/m<sup>2</sup>/sr/μm
  * Scaling factor: 0.01 (VNIR), 0.0001 (LWIR)

**Level-1B Products**

* L1B imagery assets contain per-band TOA reflectance data (for VNIR bands) and brightness temperature data (for LWIR bands).
  * Units: Unitless (VNIR); Kelvin (LWIR)
  * Scaling factor: 0.0001 (VNIR); 0.01 (LWIR)

**Conversions**

* Hydrosat provides a full suite of coefficients in product metadata for conversion between TOA radiance and reflectance (or brightness temperature). For more information on usage, see [this page](https://satdocs.hydrosat.com/product-details#conversions) or our product guide.
  {% endupdate %}

{% update date="2026-01-27" tags="thumbnails" %}

## Thumbnail Colorization Improvements (LWIR)

We've improved the contrast and visual consistency in our L1B and L2 thermal thumbnails and previews. This includes:

* Consistent scaling across the full imaging strip rather than within individual scenes.
* A switch from the `inferno` color ramp to a modified `RdYlBu_r` color ramp, where cooler pixels are shown in blue and warmer ones in red. These colors map to predictable temperatures; the breakpoint from blue to yellow occurs at approximately 0 degrees Celsius.

This change has no impacts on the underlying data.
{% endupdate %}

{% update date="2026-01-20" tags="processing" %}

## Noise Mitigation

We've implemented a minor correction for noise in the thermal products.
{% endupdate %}

{% update date="2026-01-14" tags="thumbnails" %}

## Thumbnail Colorization Improvements (RGB)

We've released a color curve approach that improves the visual contrast in our true color thumbnails. This change has no impacts on the underlying data.
{% endupdate %}

{% update date="2025-12-17" tags="cloud-mask" %}

## Updated Cloud Mask

We've released an improved cloud mask, which uses a U-Net convolutional neural network architecture. The new model outperforms our baseline Fmask approach across several key metrics.
{% endupdate %}
{% endupdates %}