ECOSTRESS中,我需要使用L2_LSTE(swath)手动处理,但是没有L1B_GEO数据,但...

Tạo vào: 10 tháng 1, 2026

Trả lời bằng GPT-5.2 Thinking bởi Chat01

Câu hỏi

ECOL2_ATBD_V2.pdf
ECOL2_User_Guide_V2.pdf

ECOSTRESS中,我需要使用L2_LSTE(swath)手动处理,但是没有L1B_GEO数据,但是存在相同时间的L2G_LSTE数据。这是什么原因?我还能获得坐标信息吗?

Suy nghĩ

Explaining L2, L2G, and L1B_GEO availability

The reason you can’t get L1B_GEO while L2G is available is that L2G is a gridded version derived from the swath L2 data, which doesn’t include L1B_GEO. L2 products have lat/lon tagged for each pixel, while L2G uses a WGS84 grid. Coordinates can be obtained from the L2G metadata, but L1B_GEO is needed for finer georeferencing.

Explaining L2_LSTE Processing and Missing L1B_GEO

L2_LSTE is swath data and requires matching geolocation data (ECO_L1B_GEO) that includes Latitude/Longitude for georeferencing. L2G is gridded, so it doesn't need GEO. GEO might be missing because L1B_GEO wasn’t downloaded, or you’re filtering for L2 only. Solution: add ECO_L1B_GEO.002 or use SceneID/StartOrbitNumber for precise searching.

Clarifying Coordinate Options and Disclaimers

L2 swath data provides per-pixel lat/lon and additional info, citing Earthdata. If unavailable, L2G (WGS84 grid) offers fixed lat/lon steps, though it's a resampled version. As a fallback, swath L2 offers approximate coordinates. Note: "lat/lon tagged" refers to relationships, not stored arrays. L1B_GEO provides geolocation. Water_mask is derived from L1B_GEO, if L2 exists.

Addressing Water Mask Information and Distribution Issues

It seems like the user not having the data points to a download or distribution issue, not a data generation one. Water_mask is derived from the L1BGEO product, as per Earthdata. While the user guide doesn’t explicitly say “extracted,” the info about water_mask is implied in certain sections. We can cite Earthdata for clarification.

Thought for 2m 56s

Trả lời

你看到的这种“有 L2G_LSTE,但没拿到同时间的 L1B_GEO”通常不是算法上矛盾,而是数据分发/检索方式导致的:

1) 为什么会出现这种情况?

  • L2_LSTE(swath)本质上是轨道条带(swath)数据,在用户指南里标注为 “Swath, (lat, lon tagged)”,尺寸是 5632×5400。同一张表也明确 L2G_LSTEGeographic, WGS84(规则经纬网格)。(ECOL2_User_Guide_V2.pdf)
  • swath 产品通常需要配套的 GEO(地理定位)文件来把“行列号 → 每个像元的纬度/经度(以及视角、太阳天顶角等)”对应起来。L2 输入数据清单里把 ECOv002_L1B_GEO列为必需输入,并明确包含 Latitude/Longitude、sensor/solar zenith、elevation、land/ocean mask 等。(ECOL2_User_Guide_V2.pdf)
  • L2G_LSTE 已经是投影到 WGS84 规则网格后的版本,所以你就算没下载 GEO,也仍然可以直接使用它(它“自带坐标体系”)。公开产品说明也写到 L2G 是从 L2 swath 重采样/投影得到的 gridded 版本。(Data.gov)
  • 另外,JPL 的产品说明里也直接写了:L2_LSTE(swath)是“to be used with L1B_GEO”,而 L2G 是已经投影好的版本。(ECOSTRESS)

所以:L2G 在你手里≠说明 L1B_GEO 不存在,更常见是你在 Earthdata/AppEEARS 下载时只选了 L2/L2G,而 L1B_GEO 是另一个独立产品,需要单独勾选/检索

2) 我还能获得坐标信息吗?

可以,按“精确程度/是否保持 swath 原始几何”分三种:

A. 最推荐:去补下载同轨同景的 ECO_L1B_GEO(v002)

  • ECO_L1B_GEO产品本身就是用来给 ECO2LSTE / L2 swath 等产品做地理定位的,并提供经纬度等地理定位层。(NASA Earthdata)
  • 你可以用 L2 文件里的标准元数据字段去匹配同一景:例如 RangeBeginningDate/Time、SceneID、StartOrbitNumber/StopOrbitNumber 等都在标准元数据表里列出。(ECOL2_User_Guide_V2.pdf)
  • 注意版本要匹配:你的 L2 是 .002(Collection 2),就尽量找 ECO_L1B_GEO.002(不要用旧的 .001 混配)。

这样你才能在保持 swath 原始几何的前提下,拿到逐像元的 lat/lon(以及视角/太阳角等)。

B. 如果你不强求 swath:直接用 L2G_LSTE当作“有坐标的替代品”

  • 用户指南明确 L2G_LSTE 是 Geographic, WGS84。(ECOL2_User_Guide_V2.pdf)
  • 公开说明也强调它是从 L2 swath 重采样并投影到固定网格得到的。(Data.gov)

代价是:L2G 相当于已经做过一次重投影/重采样,像元不再是原始 swath 的观测几何(如果你要做严格的角度相关分析或对齐原始扫描线,这会有影响)。

C. 仅靠 L2_LSTE 文件本身:通常只能拿到“范围级”信息,难以逐像元精确定位

  • L2 元数据里确实有 East/West/North/SouthBoundingCoordinate、像元间距、行列数等(可用于画大致覆盖范围)。(ECOL2_User_Guide_V2.pdf)
  • 但 swath 是倾斜轨道条带,不是规则经纬网格;没有 GEO 的逐像元 lat/lon 时,你很难可靠地把每个像元精确投到地图上(只能粗略近似)。

3) 实操建议(最省事的排查路径)

  1. 先确认你用的是 ECO_L2_LSTE.002(Collection 2)。(ECOL2_User_Guide_V2.pdf)
  2. 用 L2 文件元数据里的 SceneID / RangeBeginningTime / StartOrbitNumber 去 Earthdata Search 里检索并勾选 ECO_L1B_GEO.002 同轨同景。(ECOL2_User_Guide_V2.pdf)
  3. 如果你只是要“可投影、有坐标的 LST”,并不在意 swath 原始几何,那直接用 L2G_LSTE会更省力。(ECOL2_User_Guide_V2.pdf)

如果你愿意,把你那景数据的 L2_LSTE 文件名(或元数据里的 SceneID/RangeBeginningTime/StartOrbitNumber 任意一个)贴出来,我可以按它告诉你在 Earthdata 里应该用什么关键词/筛选条件最容易把对应的 L1B_GEO.002 精确搜出来。

Câu hỏi

我搜索了同时间的L1B_GEO,但是没有搜到

Suy nghĩ

Handling geolocation for missing L1B_GEO data

If L1B_GEO is unavailable for that time, try using the L2 file as it has lat/lon tagged from HDF-EOS geolocation relationships. Check for latitude and longitude arrays or swath fields. Also, L1B_RAD may include lat/lon centers since it’s geolocated data, but L1B_GEO is needed for angles.

Finding coordinates with L2 swath data

If you’re using the same scene as ECOv002_L1B_RAD, it might already have lat/lon because L1B is geolocated. However, it’s not guaranteed. For L2 swath, many files include geolocation, so you likely don't need L1B_GEO. You can check lat/lon in L2 or, if missing, you may need GEO.

Addressing missing L1B_GEO search results

There could be a few reasons for not finding L1B_GEO:

  • AppEEARS may not support L1B_GEO but does for L2 products. Be sure to check Earthdata Search.
  • Version mismatch between L2 and L1B_GEO.
  • Spatial searches aren't supported for swaths; use the orbit number.
  • Time mismatch from the start and end times.
  • The L2 file may be a subset where orbit and scene code need adjustments.

Providing a deterministic method for searching L1B_GEO

To find the expected L1B_GEO granule ID, use your L2 granule's StartOrbitNumber and SceneID to build the ID using the Geo dataset page format: ECOv002_L1B_GEO_<orbit>_<scene>_<YYYYMMDDTHHMMSS>_...h5. Then, search for that ID in Earthdata Search.

If the user did not provide a file name, we should suggest they provide it, though it's not required.

Thought for 3m 11s

Trả lời

你这个现象基本可以确定:不是“L2 可以生成但 L1B_GEO 不存在”,而是你在检索/分发侧没检索到或没被提供到对应的 L1B_GEO granule。因为按产品链路,L2_LSTE 的生成明确依赖 ECOv002_L1B_GEO(里面有 Latitude/Longitude、传感器/太阳天顶角、DEM、陆海掩膜 等)。(ECOL2_User_Guide_V2.pdf)

下面给你一套“最常见原因 + 还能不能拿到坐标 + 怎么定位到对应 granule”的实操路线。


你为什么会搜不到同时间的 L1B_GEO?

1) 你可能在 AppEEARS 里找

用户指南只明确说 L2 产品可以在 LP DAAC(Earthdata Search)或 AppEEARS 获取,(ECOL2_User_Guide_V2.pdf)
L1B(含 L1B_GEO)很多时候不在 AppEEARS 的可选清单里。如果你是在 AppEEARS 里“按同时间”找,很容易就是“根本不提供”。

✅ 解决:去 **Earthdata Search(LP DAAC)**里找 L1B_GEO。

2) 版本/集合选错:你需要的是 Collection 2 的 L1B_GEO(v002)

L2 Collection 2 的输入表写的是 ECOv002_L1B_GEO。(ECOL2_User_Guide_V2.pdf)
如果你搜的是 v001(或没选到 v002 的 collection),会出现“时间对得上但结果为空”的错觉。

✅ 解决:Earthdata Search 里确认选择的是 ECO_L1B_GEO 的 V002/Collection 2(数据集页面也写了 “V002”)。(NASA Earthdata)

3) 你用“精确时刻”卡得太死/时刻字段不一致

ECOSTRESS 一个 scene 大约 ~52 秒(44 扫描)。(ECOL2_User_Guide_V2.pdf)
不同产品在元数据里用的时间字段(开始/结束/代表时刻)可能有秒级差异。你如果只用一个“精确到秒”的时间点筛选,有时会漏掉。

✅ 解决:时间窗口放宽(至少 ±5 分钟,建议先 ±1 小时试一次)。

4) 你按“空间范围”去找 swath 产品(会踩坑)

LP DAAC 有个 swath 检索的 quick guide 提醒:很多 ECOSTRESS swath 产品在 Earthdata Search 里不能用空间范围精确过滤,需要用 orbit number 来找,并建议用能定位的产品先拿到 orbit 再关联其它产品。(LP DAAC)

✅ 解决:用 orbit/scene 来搜(下面给你方法)。


我还能拿到坐标吗?

A. 最稳妥:坐标通常可以直接从 L2_LSTE 文件本身拿到

用户指南多处强调:L2/L2 swath 是 “lat/lon tagged” 的 swath。(ECOL2_User_Guide_V2.pdf) (ECOL2_User_Guide_V2.pdf)
而 HDF-EOS 的 swath/geo 结构本身就支持把 SDS 和经纬度建立映射关系(ATBD 里也解释了这种 geolocation relationship)。(ECOL2_ATBD_V2.pdf)

✅ 你可以先在 L2_LSTE 的 HDF5 结构里找类似这些路径/字段(不同 build 可能略有差异):

  • .../HDFEOS/SWATHS/.../Geolocation Fields/Latitude
  • .../HDFEOS/SWATHS/.../Geolocation Fields/Longitude
  • 或直接叫 latitude / longitude 的数据集

如果找得到,你不需要 L1B_GEO 就能拿到逐像元经纬度(只是缺少一些你可能也想要的几何角、DEM 等辅助层——那些在 L1B_GEO 里定义得很明确)。(ECOL2_User_Guide_V2.pdf)

一个快速自查的 Python(只列出包含 lat/lon 的数据集名):

python
import h5py fn = "你的_ECO_L2_LSTE.h5" hits = [] with h5py.File(fn, "r") as f: def visitor(name, obj): if hasattr(obj, "shape"): low = name.lower() if "lat" in low or "lon" in low: hits.append((name, obj.shape, str(obj.dtype))) f.visititems(visitor) for h in hits: print(h)

B. 如果你不坚持 swath:直接用 L2G_LSTE(WGS84)

L2G 是 gridded 产品,投到 Geographic/WGS84 网格上了。(ECOL2_User_Guide_V2.pdf)
它天然可用作“带坐标的 LST”。代价是:它已经重采样/投影过,不再保留原始 swath 的观测几何(做角度相关/严格共定位时要注意)。


如果你仍然需要把 L2_LSTE 和 L1B_GEO 配对:用 orbit/scene 精准定位

你可以从 L2_LSTE 的标准元数据里直接拿到用于配对的字段(例如 SceneID, RangeBeginningDate/Time, StartOrbitNumber, StopOrbitNumber 等)。(ECOL2_User_Guide_V2.pdf)

然后去 Earthdata Search 里用这些信息定位 ECO_L1B_GEO V002 的 granule。

另外,L1B_GEO 的文件命名是带 orbit/scene/UTC 时间戳 的(数据集页面给了示例命名)。(NASA Earthdata)
所以最“硬核”的检索方式是:把你 L2 的 StartOrbitNumber + SceneID 拼到文件名关键字里搜索(哪怕时间差几秒也不怕)。


你现在可以怎么做(最省力的下一步)

  1. 先在 L2_LSTE 文件里搜一下纬度/经度数据集(上面的 Python 就是干这个的)。因为它按定义就是 lat/lon tagged swath。(ECOL2_User_Guide_V2.pdf)
  2. 如果 L2 里确实没有逐像元 lat/lon(少见),再用 L2 的 StartOrbitNumber/SceneID 去 Earthdata Search 找 ECO_L1B_GEO V002。(ECOL2_User_Guide_V2.pdf) (NASA Earthdata)
  3. 如果你只是要“能用的坐标+LST”,直接用 **L2G_LSTE(WGS84)**就能开干。(ECOL2_User_Guide_V2.pdf)

如果你把 L2_LSTE 的文件名贴出来(或把元数据里的 StartOrbitNumber + SceneID 贴出来),我可以按这两个字段告诉你在 Earthdata Search 里应该用什么关键词最容易“一把搜到”对应的 L1B_GEO granule。

Câu hỏi

我的LSTE是ECOv002_L2_LSTE_12510_003_20200919T173735_0712_02.h5,我应该怎么搜索

Suy nghĩ

Providing guidance for Earthdata search

The user is asking how to search for L1B_GEO. I’ll guide them through the Earthdata search process using the dataset “ECO_L1B_GEO.002” and granule search by orbit number or timestamp. There may be changes after 2025, but I’ll provide general steps based on the user guide and avoid using web references.

Suggesting steps to search L1B_GEO data

Instead of searching by timestamp alone, I’ll advise the user to search by orbit and scene. Using the filename fields, they can try searches like "12510_003_20200919T173735." I'll guide them to find orbit and scene data from the metadata in the L2 file. I’ll also explain how to search in Earthdata, applying a time range around 2020-09-19.

Explaining Earthdata granule search

To search by orbit and scene ID, the user can enter 12510_003 or 12510 in Earthdata's granule search. If this doesn't work, they can filter with the LocalGranuleID field using strings like ECOv002_L1B_GEO_12510_003_20200919T1737. Some advanced search options might require extra tools like the earthaccess Python library if needed for more complex queries.

Proposing Earthdata Search approach

I suggest searching in Earthdata by selecting L1B_GEO.002 and then using the “Granules” section. You can filter by attributes, like StartOrbitNumber, if available. I recommend searching for granule names like ECOv002_L1B_GEO_12510_003_20200919T173735. Also, note that some data may be missed if from a different provider or mission dataset.

Suggesting methods for obtaining coordinate info from L2

While L1B_GEO is typically used for geolocation, L2 files are lat/lon tagged and may contain these coordinates. I’d suggest extracting Latitude and Longitude directly from the L2 file. You can also use HDF-EOS geolocation, but Earthdata Search may help with further info. I'll guide on accessing via metadata as well.

Thought for 1m 27s

Trả lời

你的文件名里其实已经给了配对检索 L1B_GEO 的关键信息

ECOv002_L2_LSTE_12510_003_20200919T173735_0712_02.h5

  • 12510:轨道号(orbit)
  • 003:SceneID(场景号)
  • 20200919T173735:时间戳(通常就是这一景的开始/代表时刻附近;一景大约 52 秒)(ECOL2_User_Guide_V2.pdf)

而且从算法链路上,L2_LSTE 的生成需要用到 ECOv002_L1B_GEO(里面包含 Latitude/Longitude、sensor/solar zenith、elevation、land/ocean mask 等)(ECOL2_User_Guide_V2.pdf)。所以“搜不到”更像是检索方式/筛选条件问题,而不是这景没有 GEO。


在 Earthdata Search 上怎么搜(最容易命中)

Step 1:先选对数据集(Collection)

Collections 里不要搜 “L1B_GEO” 这种泛词,直接搜 ECO_L1B_GEO.002(注意是 .002/Collection 2,与你的 ECOv002 对应)。

你现在的 L2 是 Collection 2;用户指南里所有相关短名也都是 .002 这一套(ECOL2_User_Guide_V2.pdf)。

Step 2:时间不要卡死(给个窗口)

Granules 的时间筛选里,先用一个宽松窗口,比如:

  • Start:2020-09-19 17:30:00
  • End:2020-09-19 17:45:00

原因:一景本来就有几十秒长度(ECOL2_User_Guide_V2.pdf),而不同产品的元数据时间字段(开始/结束/代表时刻)可能有秒级差异。

如果还没有,再放宽到 ±1 小时(17:00–18:30)通常就能把“秒级不一致”排除掉。

Step 3:用“轨道号 + SceneID”去过滤 granule(命中率最高)

在 granule 的“搜索/过滤框”(不同页面叫法可能是 Granule ID / Search within results)里依次试:

  1. 12510_003
  2. 12510
  3. 20200919T173735
  4. ECOv002_L1B_GEO_12510_003

很多时候 Earthdata 的 granule 名称就是把这些字段拼在一起(你 L2 就是这样拼的),所以用这几个子串通常能直接筛出来。


如果还是搜不到:用 L2 文件里的元数据去“反查”

你的 L2 文件标准元数据里明确就有这些用于配对检索的字段:RangeBeginningDate/TimeSceneIDStartOrbitNumberStopOrbitNumber、以及本地粒度名 LocalGranuleID 等(ECOL2_User_Guide_V2.pdf)。
建议你直接从 L2 的 root attributes 里读出:

  • StartOrbitNumber(应当就是 12510)
  • SceneID(应当就是 003)
  • LocalGranuleID(通常就是完整文件名/粒度名)

然后把 LocalGranuleIDStartOrbitNumber + SceneID 丢到 Earthdata 的 granule 搜索框里,往往比“按时间”更稳。


你还需要坐标吗?其实 L2_LSTE 很可能已经自带逐像元 lat/lon

用户指南明确说:L2 产品是 swath 且每个像元 lat/lon tagged(ECOL2_User_Guide_V2.pdf);并且 HDF-EOS 的 swath 结构就是用来建立“数据集 ↔ 经纬度”关系以支持映射(ECOL2_ATBD_V2.pdf)。
所以即使你没拿到 L1B_GEO,你仍然很可能能从 L2_LSTE 文件里直接读到 Latitude / Longitude 数据集

你可以用下面这个 Python 快速扫一遍文件里有没有 lat/lon(只要把文件路径改成你的):

python
import h5py fn = "ECOv002_L2_LSTE_12510_003_20200919T173735_0712_02.h5" hits = [] with h5py.File(fn, "r") as f: def visitor(name, obj): if hasattr(obj, "shape"): low = name.lower() if "lat" in low or "lon" in low: hits.append((name, obj.shape, str(obj.dtype))) f.visititems(visitor) for h in hits: print(h)

常见路径会长得像(示例):

  • .../HDFEOS/SWATHS/.../Geolocation Fields/Latitude
  • .../HDFEOS/SWATHS/.../Geolocation Fields/Longitude

备选:如果你不一定要 swath,L2G 直接就是 WGS84

你已经有同时间的 L2G_LSTE,它是 Geographic/WGS84 网格(ECOL2_User_Guide_V2.pdf),天然可用作“带坐标的 LST”。


我建议你下一步这样做(最省力)

  1. 先用上面的脚本确认 L2_LSTE 里是否已经有 Latitude/Longitude(很多情况下有)。
  2. 同时在 Earthdata Search 里按我给的顺序:选 ECO_L1B_GEO.002 → 时间放宽 → 搜 12510_003

如果你愿意,把你从 L2 元数据里读到的 **RangeBeginningDate/TimeLocalGranuleID(或截图)**贴出来,我可以按这些字段帮你把 Earthdata 上最可能匹配的 granule 检索词再缩到“基本一把命中”。

Câu hỏi

image.pngimage.png

只搜到这些数据,没有003

Python

python
from PIL import Image, ImageEnhance img = Image.open('/mnt/data/image.png') img.size (1396, 1706)

Python

python
import matplotlib.pyplot as plt, numpy as np plt.figure(figsize=(10,12)) plt.imshow(img) plt.axis('off') plt.show()

Suy nghĩ

Explaining missing scene 003 and coordinates access

It looks like orbit 12510 in the L1B_GEO collection only contains scenes 008-022, so scene 003 is absent. This could be due to a missing granule or a mismatch in orbit numbers. Their L2 file might be based on an internal orbit number or an earlier equatorial crossing. Checking the StartOrbitNumber in their L2 file could clarify further.

Explaining missing scene 003 and L2 coordinate access

Scenes earlier than 008 may not have been archived due to instruments’ acquisition strategy, exclusions from radiation regions like SAA, or pauses in acquisitions. User’s L2 granule might have come from another source. However, coordinates can still be obtained from the L2 file, which includes lat/lon tagging. They should also verify through file attributes or search attributes within the L2 dataset itself.

Explaining how to track down missing scene and obtain coordinates

Cite the L2 input requirements for L1B_GEO and mention scene timing mismatch (each scene 52 seconds). The screenshot shows no scene 003, likely due to orbit ID mismatch. To search in Earthdata Search, remove the orbit filter and search by time or use time-based substrings. Ultimately, L2 can still provide lat/lon arrays, and I’ll share Python code for that.

Explaining ways to retrieve coordinates

For coordinate retrieval, there are a couple of options. If L2 includes Latitude and Longitude as separate datasets, you can use those for geotransform creation. Alternatively, you can convert to GeoTIFF with tools like rasterio/gdal. I’ll also share Python code to extract lat/lon from L2 dataset and clarify the relationship to geolocation fields in the HDF-EOS structure.

Thought for 3m 20s

Trả lời

从你截图来看,你的检索其实是“成功的”——只是在 ECO_L1B_GEO.002 这个集合里,Orbit=12510 只发布了 9 个 granule,SceneID 分别是 008、010、011、013、015、019、020、021、022(最早开始时间约 17:54 UTC)。因此你找不到 ..._12510_003_20200919T173735... 对应的 L1B_GEO,不是你操作问题,而是 该集合里确实没有 SceneID=003 这一粒(至少在你当前看到的发布结果里)。

这就会导致一个看起来矛盾的现象:你手里有 ECOv002_L2_LSTE_12510_003_20200919T173735_0712_02.h5,但配套的 L1B_GEO 却缺失。


1) 可能原因(按常见程度)

A. 你的 L2 granule 的 “orbit/scene 标号” 与 Earthdata Search 里 L1B_GEO 使用的元数据不一致

ECOSTRESS 的 L2 场景是 swath,每景大约 52 秒(44 次扫描)(ECOL2_User_Guide_V2.pdf);不同处理链/再处理批次如果对“scene 切分/编号”规则有差异,就可能出现你看到的 “L2 有 003,但 L1B_GEO 集合里从 008 才开始”的情况。

✅ 建议你先以文件内元数据为准核对一次(见下面第 2 部分代码),尤其是:

  • StartOrbitNumber
  • SceneID
  • RangeBeginningDate/Time

这些字段在标准元数据里定义过(ECOL2_User_Guide_V2.pdf)。

B. 该 L1B_GEO granule 在 LP DAAC/云端集合中“缺粒/撤下/未发布”

从算法链路上,L2 生产确实需要 L1B_GEO(包含 Latitude/Longitude、传感器/太阳天顶角、DEM、陆海掩膜 等)(ECOL2_User_Guide_V2.pdf)。
所以如果你确认文件内 StartOrbitNumber=12510SceneID=003,那更像是 L1B_GEO.002 这个集合里缺了对应 granule,而不是 L2 真的“无 GEO 生成”。


2) 你仍然能不能获得坐标信息?

✅ 能,而且大概率“直接就在 L2_LSTE 里”

用户指南明确:L2 产品是 swath format,每个像元 lat/lon tagged(ECOL2_User_Guide_V2.pdf),并且 L2 “包含一个标准地理(lat, lon tagged)的 swath 产品”(ECOL2_User_Guide_V2.pdf)。
另外 HDF-EOS swath 结构本身就用于建立 “SDS ↔ 经纬度” 的地理定位关系(ECOL2_ATBD_V2.pdf)。

也就是说:即便你拿不到单独的 L1B_GEO 文件,L2_LSTE 通常也能读出逐像元 Latitude/Longitude(或通过 swath 关系读取)。

你可以用下面这段 Python 做两件事:

  1. 读出 L2 文件内的 StartOrbitNumber/SceneID/RangeBeginningTime,确认是否真的是 12510/003/17:37:35;
  2. 扫描文件里有没有 Latitude/Longitude 数据集。
python
import h5py fn = "ECOv002_L2_LSTE_12510_003_20200919T173735_0712_02.h5" with h5py.File(fn, "r") as f: # 1) 打印根属性(不同文件可能属性挂载位置略不同;先看 root) print("Root attrs keys:", list(f.attrs.keys())) for k in ["StartOrbitNumber", "StopOrbitNumber", "SceneID", "RangeBeginningDate", "RangeBeginningTime", "RangeEndingDate", "RangeEndingTime", "LocalGranuleID"]: if k in f.attrs: print(k, "=", f.attrs[k]) # 2) 全文件扫 lat/lon 数据集 hits = [] def visitor(name, obj): if hasattr(obj, "shape"): low = name.lower() if "lat" in low or "lon" in low: hits.append((name, obj.shape, str(obj.dtype))) f.visititems(visitor) print("\nLat/Lon-like datasets:") for h in hits: print(h)

如果你扫到了类似 .../Geolocation Fields/Latitude.../Longitude(名字可能略有不同),那就可以直接用它们作为逐像元坐标来配准/出图。

✅ 如果你不坚持 swath:直接用 L2G_LSTE

你已经有同时间的 L2G_LSTE,它是 Geographic/WGS84 网格产品(ECOL2_User_Guide_V2.pdf),天然带坐标(不需要 L1B_GEO)。
代价是:L2G 是格网化后的结果,不再保持原始 swath 几何。


3) 如果你“必须”要 L1B_GEO(为了角度、DEM、陆海掩膜等)

L1B_GEO 里确实包含这些:land/ocean mask、elevation、sensor/solar zenith angles、latitude/longitude(ECOL2_User_Guide_V2.pdf)。如果 LP DAAC 这一粒缺失,你有三个实操方向:

  1. 不要用 orbit=12510 过滤,改用时间窗口(2020-09-19 17:30–17:45 UTC)在 ECO_L1B_GEO.002 集合里搜,看看它是否其实被标到了别的 orbit 号下(这一步用来排除“编号不一致”)。
  2. 用你 L2 文件内的 RangeBeginningTime/LocalGranuleID 去 Earthdata Search 的 Search within results 里直接搜子串(比如 20200919T1737)。
  3. 若仍然确认为缺粒:你只能用 L2 内置的 lat/lon(以及 L2 自带的 water_mask 等)继续做坐标相关工作;角度/DEM 等 GEO 专有层就拿不到完整版本(L2 里有些信息会以派生形式出现,比如 water_mask 是从 L1BGEO 提取后附在 L2 里的(ECOL2_User_Guide_V2.pdf))。

如果你把上面脚本打印出来的这几个值贴我一下:StartOrbitNumberSceneIDRangeBeginningDate/Time(来自文件内属性),我就能判断到底是 “L2 文件名的编号与文件内元数据不一致”,还是 “LP DAAC 的 L1B_GEO.002 确实缺了这一粒”,然后给你对应的最短处理路径(继续用 L2 自带 lat/lon,还是换检索策略)。

Câu hỏi

===正在分析文件: ECOv002_L2_LSTE_12510_003_20200919T173735_0712_02.h5===

[1. 核心科学波段 (Data Fields)]
(未找到标准的 HDFEOS/GRIDS 结构,可能不是标准 ECOSTRESS 文件)

[2. 文件内所有数据集 (完整列表)]
路径 (Path) | 尺寸 (Shape) | 类型

L2 LSTE Metadata/AncillaryNWP | () | object
L2 LSTE Metadata/BandSpecification | (6,) | float32
L2 LSTE Metadata/CloudMaxTemperature | (1,) | float64
L2 LSTE Metadata/CloudMeanTemperature | (1,) | float64
L2 LSTE Metadata/CloudMinTemperature | (1,) | float64
L2 LSTE Metadata/CloudSDevTemperature | (1,) | float64
L2 LSTE Metadata/Emis1GoodAvg | (1,) | float64
L2 LSTE Metadata/Emis2GoodAvg | (1,) | float64
L2 LSTE Metadata/Emis3GoodAvg | (1,) | float64
L2 LSTE Metadata/Emis4GoodAvg | (1,) | float64
L2 LSTE Metadata/Emis5GoodAvg | (1,) | float64
L2 LSTE Metadata/LSTGoodAvg | (1,) | float64
L2 LSTE Metadata/NWPSource | () | object
L2 LSTE Metadata/NumberOfBands | (1,) | uint8
L2 LSTE Metadata/OrbitCorrectionPerformed | () | object
L2 LSTE Metadata/QAPercentCloudCover | (1,) | int32
L2 LSTE Metadata/QAPercentGoodQuality | (1,) | int32
SDS/Emis1 | (5632, 5400) | uint8
SDS/Emis1_err | (5632, 5400) | uint16
SDS/Emis2 | (5632, 5400) | uint8
SDS/Emis2_err | (5632, 5400) | uint16
SDS/Emis3 | (5632, 5400) | uint8
SDS/Emis3_err | (5632, 5400) | uint16
SDS/Emis4 | (5632, 5400) | uint8
SDS/Emis4_err | (5632, 5400) | uint16
SDS/Emis5 | (5632, 5400) | uint8
SDS/Emis5_err | (5632, 5400) | uint16
SDS/EmisWB | (5632, 5400) | uint8
SDS/LST | (5632, 5400) | uint16
SDS/LST_err | (5632, 5400) | uint8
SDS/PWV | (5632, 5400) | uint16
SDS/QC | (5632, 5400) | uint16
SDS/cloud_mask | (5632, 5400) | uint8
SDS/water_mask | (5632, 5400) | uint8
StandardMetadata/AncillaryInputPointer | () | object
StandardMetadata/AutomaticQualityFlag | () | object
StandardMetadata/AutomaticQualityFlagExplanation | () | object
StandardMetadata/BuildID | () | object
StandardMetadata/CampaignShortName | () | object
StandardMetadata/CollectionLabel | () | object
StandardMetadata/DataFormatType | () | object
StandardMetadata/DayNightFlag | () | object
StandardMetadata/EastBoundingCoordinate | (1,) | float64
StandardMetadata/FieldOfViewObstruction | () | object
StandardMetadata/HDFVersionID | () | object
StandardMetadata/ImageLineSpacing | (1,) | float64
StandardMetadata/ImageLines | (1,) | int32
StandardMetadata/ImagePixelSpacing | (1,) | float64
StandardMetadata/ImagePixels | (1,) | int32
StandardMetadata/InputPointer | () | object
StandardMetadata/InstrumentShortName | () | object
StandardMetadata/LocalGranuleID | () | object
StandardMetadata/LongName | () | object
StandardMetadata/NorthBoundingCoordinate | (1,) | float64
StandardMetadata/PGEName | () | object
StandardMetadata/PGEVersion | () | object
StandardMetadata/PlatformLongName | () | object
StandardMetadata/PlatformShortName | () | object
StandardMetadata/PlatformType | () | object
StandardMetadata/ProcessingEnvironment | () | object
StandardMetadata/ProcessingLevelDescription | () | object
StandardMetadata/ProcessingLevelID | () | object
StandardMetadata/ProducerAgency | () | object
StandardMetadata/ProducerInstitution | () | object
StandardMetadata/ProductionDateTime | () | object
StandardMetadata/ProductionLocation | () | object
StandardMetadata/RangeBeginningDate | () | object
StandardMetadata/RangeBeginningTime | () | object
StandardMetadata/RangeEndingDate | () | object
StandardMetadata/RangeEndingTime | () | object
StandardMetadata/RegionID | () | object
StandardMetadata/SISName | () | object
StandardMetadata/SISVersion | () | object
StandardMetadata/SceneID | () | object
StandardMetadata/ShortName | () | object
StandardMetadata/SouthBoundingCoordinate | (1,) | float64
StandardMetadata/StartOrbitNumber | () | object
StandardMetadata/StopOrbitNumber | () | object
StandardMetadata/WestBoundingCoordinate | (1,) | float64

Suy nghĩ

Explaining file limitations and possible causes

The user's file is missing HDFEOS/SWATHS and lat/lon arrays, so it lacks per-pixel coordinates, leaving only bounding coordinates. This might be because it's in a simplified HDF5 format that excludes geolocation structures. To help, they could check root attributes with commands like h5dump -n or gdalinfo.

Explaining missing L1B_GEO and possible causes

It’s possible the user downloaded their L2 data from a different host, like ORNL DAAC, even though the file name suggests JPL. Another explanation might be that their L1B_GEO search results start at a later time than expected, indicating missing sections of the orbit due to invalid geolocation or storage restrictions.

Checking StartOrbitNumber for possible mismatch

It’s possible the L2 file doesn’t actually use orbit 12510, given the time mismatch. The orbit number might be based on a predicted orbit or a corrected one. If they check the StartOrbitNumber field in their file’s metadata, they can use that for a more accurate search on Earthdata.

Suggesting queries and coordinate options

For Earthdata Search, after selecting the collection, they can search within results using identifiers like T1737 or 12510_003. If their search still shows limited results, their metadata suggests missing scenes. For coordinates, they can use L2G_LSTE with WGS84, approximate with bounding boxes, or find a match in L1B_GEO, though using v002 is recommended.

Assessing missing geo data and options

It seems like the dataset could be missing necessary geolocation data, possibly because it was processed into a simplified format without HDF-EOS geolocation arrays. To fix this, I’d recommend redownloading the original L2 file or using direct access to the original format. If the file is smaller than expected, it confirms the issue.

Guidance on searching and validation

To clear up the missing coordinates, I’d suggest inspecting the file with ncdump -h or h5dump -H to confirm the lack of lat/lon. Since the file might not follow the expected "Geolocation Fields" format, I recommend using L2T for accurate georeferencing, or checking using StartOrbitNumber, SceneID, and RangeBeginningDateTime when searching in Earthdata.

Clarifying geolocation options for the user

Upon reviewing the user’s file, it lacks the expected lat/lon datasets. The swath L2 file is described as lat/lon tagged, but it may not contain full geolocation information depending on how it was processed—or packaging might have removed it. To resolve this, use L1B_GEO for precise geolocation or alternative gridded products.

Exploring possible methods for geo-coordinates

The user’s script checks groups but may miss those with no datasets. He could recheck by listing groups, though ‘HDFEOS’ might not show if empty. For coordinates, we can suggest using L2G products, which might share dimensions with L2 swath data, possibly providing a way to map from one to the other even if geometry isn't exactly identical.

Addressing user’s processing needs for L2 and geolocation

If the user must work with L2_LSTE (swath) and lacks L1B_GEO, they could use L2G or L2T as alternatives. For searching, check metadata like StartOrbitNumber and SceneID. In Earthdata, use filters for orbit number and time, and search for specific geolocation labels. If results show no match, use L2G or L2T for coordinates instead. Also, explain that L2's algorithm depends on L1B_GEO, but the archive might not always include corresponding geolocation data.

Providing L2 geolocation process and Earthdata search guidance

I can show a simple code to extract scalar values from datasets using h5py. For coordinates, if direct lat/lon isn’t available, the L2 granule might not include them in datasets, but there could be a relation through metadata. For Earthdata search, remove the orbit filter and search using a time window to find the correct orbit.

Explaining missing lat/lon in L2 and alternatives

It’s normal for L2 files not to include lat/lon datasets; they are in L1B_GEO. If you can’t find L1B_GEO for your scene, it’s likely that these specific granules weren’t published. Workarounds include using L2G or searching other collections for L1B_GEO. You can also use bounding box coordinates.

Thought for 3m 51s

Trả lời

从你贴出来的文件结构看(只有 SDS/*StandardMetadata/*,没有 Latitude/Longitude 之类的数据集),这其实很符合 ECOSTRESS L2_LSTE 的产品设计:L2_LSTE 主要给“地球物理量”(LST、Emis、QC、PWV、cloud_mask、water_mask 等),而逐像元的几何/经纬度是在单独的 L1B_GEO 里(它包含 Latitude/Longitude、sensor/solar zenith angles、elevation、land/ocean mask 等)。(ECOL2_User_Guide_V2.pdf) (ECOL2_User_Guide_V2.pdf)

换句话说:

  • 文档会描述 L2 是“swath / lat-lon tagged”(按条带观测组织,并可地理定位),(ECOL2_User_Guide_V2.pdf)
  • 真正用于地理定位的经纬度场并不一定打包在 L2_LSTE 文件里,而是依赖 L1B_GEO(输入链路也明确需要它)。(ECOL2_User_Guide_V2.pdf)
  • ATBD 也解释过 HDF-EOS 机制会用结构/关系把 SDS 和地理坐标关联起来以支持制图,但你这份文件看起来就是“简化 HDF5(SDS+metadata)”风格,因此你看不到 HDFEOS/SWATHS 那套结构。(ECOL2_ATBD_V2.pdf)

为什么你在 Earthdata Search 里找不到 12510_003 的 L1B_GEO?

你截图里已经证明:在 ECO_L1B_GEO.002 这个集合里,Orbit=12510 只发布了少数 scene(008、010、011…),确实没有 003。
这通常意味着两类情况之一:

  1. 编号不一致:L2 文件名里的 orbit/scene 可能和文件内 StandardMetadata/StartOrbitNumberSceneID 不一致(或后续再处理改过编号)。这种情况用“文件内元数据”重新检索,往往就能找到。
  2. 确实缺粒/未发布:某些早段 scene 的 L1B_GEO granule 可能因质量/处理/归档原因没有在该集合对外发布,但下游 L2 文件仍在你手里(例如来自旧下载/不同分发路径/缓存)。

我建议你先做一个最关键的排查:以文件内元数据为准确认 orbit/scene/时间

读出文件内元数据(用它来搜,而不是用文件名)

python
import h5py import numpy as np fn = "ECOv002_L2_LSTE_12510_003_20200919T173735_0712_02.h5" keys = ["StartOrbitNumber","StopOrbitNumber","SceneID", "RangeBeginningDate","RangeBeginningTime", "RangeEndingDate","RangeEndingTime", "LocalGranuleID","CollectionLabel","BuildID"] def to_str(x): if isinstance(x, bytes): return x.decode("utf-8", "ignore") if isinstance(x, np.ndarray): return x.astype(str).tolist() return str(x) with h5py.File(fn, "r") as f: for k in keys: path = f"StandardMetadata/{k}" if path in f: print(k, "=", to_str(f[path][()]))
  • 如果 StartOrbitNumber/SceneID 读出来并不是 12510/003,那你就按读出来的值去 Earthdata Search 里筛 orbit/scene,会立刻不同。
  • 如果读出来仍是 12510/003,而且时间也在 17:37 左右,那基本可以判定:公开的 L1B_GEO.002 集合里缺这一粒

那我还能获得坐标信息吗?

分三种“可行度”:

方案 A(最省事、最稳):直接用 L2G_LSTE.002

L2G_LSTE 是 Geographic / WGS84(规则经纬网格),天然带坐标,可直接进 GIS / xarray / rasterio。(ECOL2_User_Guide_V2.pdf)
如果你的目的主要是“有坐标的地表温度/发射率”,这就是最佳替代。

方案 B(仍想用 swath):想要逐像元经纬度,就必须拿到 L1B_GEO

因为 L1B_GEO 明确就是经纬度/角度/DEM/陆海掩膜的载体。(ECOL2_User_Guide_V2.pdf)
如果 L1B_GEO.002 缺粒,你可以试两个补救方向:

  • 在 Earthdata Search 里改搜 ECO_L1B_GEO.001(Collection 1),用同一时间窗口(比如 2020-09-19 17:30–17:45 UTC)看看 v001 是否有这粒。
    • 如果 v001 有,你可以谨慎把它当作地理定位来源(可能存在小差异,做高精度共定位要留意)。
  • 或者改用 L2T_LSTE.002(UTM tiled GeoTIFF)(同样是“带坐标”的发布形态,适合制图/分析)。(ECOL2_User_Guide_V2.pdf)

方案 C(不推荐但能“凑合”):只用边界框元数据做粗定位

你文件里有 East/West/North/SouthBoundingCoordinate 等边界信息,但这只能给出覆盖范围,不能恢复 swath 每个像元的精确 lat/lon(条带几何不是一个简单仿射变换)。所以除非你只是画个大概范围,不建议走这条。


你下一步怎么做(按优先级)

  1. 先跑上面的元数据读取脚本:确认真实 StartOrbitNumber/SceneID/RangeBeginningTime
  2. 如果确实缺 L1B_GEO.002:
    • 需要坐标就直接用 L2G_LSTE.002(WGS84) (ECOL2_User_Guide_V2.pdf)
    • 或尝试找 L1B_GEO.001(同时间窗)作为地理定位备选。
  3. 如果你把脚本输出的 StartOrbitNumber、SceneID、RangeBeginningDate/Time 贴出来,我可以按这三个字段给你一个“在 Earthdata Search 里最可能命中的检索组合”(包括该用 orbit filter 还是 time filter、以及在 granule 列表里该搜哪个子串)。

Câu hỏi

StartOrbitNumber = 12510
StopOrbitNumber = 12510
SceneID = 003
RangeBeginningDate = 2020-09-19
RangeBeginningTime = 17:37:35.543614
RangeEndingDate = 2020-09-19
RangeEndingTime = 17:38:27.513077
LocalGranuleID = ECOv002_L2_LSTE_12510_003_20200919T173735_0712_02.h5
CollectionLabel = V002
BuildID = 0712

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